Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: sluckey on December 16, 2010, 05:59:01 am
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Ever since I restored the Maggie M10-A, I've been intrigued with the pitch shifting vibrato idea. A few months back FYL posted some info on a Wurlitzer organ vibrato circuit. That got me thinking, "What's going on with the old Hammond organ vibratos?" I've seen many of the small vibrato units on eBay for cheap! Maybe it could be converted to guitar use.
Well, it's actually pretty easy to convert them for guitar use. Here's my project...
(http://home.comcast.net/~seluckey/amps/warbler.jpg) (http://home.comcast.net/~seluckey/amps/warbler/warbler.htm)
(Click on the pic for more info)
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Good morning Steve! That's a great project, and your presentations are all very thorough. I should check back on your website more often.
Cheers,
Chip
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Really sweet, Steve!
Comments on the sound?
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But does it sound as interesting as it looks? (And what do all those bottles do? Any chance of a schematic?)
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Comments on the sound?
Ha! I'll try. Have you ever heard a Magnatone? This is very very similar, but since the Hammond uses three shifting stages (Maggies use only one or two)the sound is fuller than the Maggie and even comes close to a chorus pedal when set right. There's an almost liquid or fluid sound when set to very slow and strong. And fast sounds kinda psychedelic. Set it to medium speed and strength and it sounds really good on Clapton's middle guitar part on Badge. It does suck some of the twang out of a guitar though.
I can't really describe how this sounds, but it works better on clean guitar. I can almost hear (imagine) some of your stuff thru this vibrator. I don't even own a mic, but I may be able to do a line level patch into my computer and record something. I'll let you know if I come up with some sound bytes.
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But does it sound as interesting as it looks? (And what do all those bottles do? Any chance of a schematic?)
The sound is the best part. One bottle is an input/output buffer to get the guitar signal high enough to drive the vibrator unit. Two bottles are the actual phase shift modulator. One more bottle is the LFO and driver, similar to a Fender trem osc/driver.
Look again at the web page. Near the top you'll see a pdf with the actual Hammond AO-41 and AO-47 schematics and a therory of operation. At the bottom of the page is my usual Visio drawn schematic and layout for my as built circuit in pdf format.
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That was George playin the bridge part (thru a Leslie), payin back Clapton for playin on the Beatles White,"While my Guitar Gently Weeps".
Brad :smiley:
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That is one nicely done project! You are a true craftsman!
That drill press has seen some mile,with all the surface rust,eh?
I built a very simple pitch-shifting vibrato in my V-Verb amps,no where near as complicated as the Hammond and likely not as nice sounding.
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Sluckey,
I was hoping you'd share some info on that project. I got to hand it to you, you are a MASTER at these projects and documenting them for the benefit of others.
My hat is off to you! That looks like a fabulously successful project. Bravo!
The one time we met and jammed, I remember you showing me the riff for Badge so it gives me a good mental picture of what this thing probably sounds like with you playing thru it.
:icon_thumright:
THANKS so much for sharing it! You sure come up with some innovative approaches and they always look incredibly well done.
Best regards, Tubenit
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That drill press has seen some mile,with all the surface rust,eh?
Sure looks that way. Actually, the gulfcoast is just a rusty place to live. I could go down to the bay and pick up a bucket of oil for a lube job. :grin:
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sluckey,
What is that Trany in the cathode circuit? I'm thinkin, it's part of whats wobblin the cathodes? But why a trany, for isolation from the LFO? From the text, is this trany being used as some kind of LC low pass, or has freq. got nothing to do with it? :icon_scratch: Got any idea's of what could be swapped in as a sub.? Hopfully something could be bought off the shelf? Maybe 3 seperate units? I'd like to do this build too. I love this/these's kinds of FX.
Thanks, Brad :smiley:
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That was George playin the bridge part (thru a Leslie), payin back Clapton for playin on the Beatles White,"While my Guitar Gently Weeps".
Brad :smiley:
Sorry to say, but that isn't true. George played the rhythm guitar part, while Clapton didn't play on the song at all until the Leslie part came in. Clapton is playing the leslie part and the solo. There have been quite a few interviews over the years where Harrison alludes to this song and Clapton's playing on it.
Greg
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The tranny is not a standard transformer. It's a saturable reactor. This unit has three mounted on a common frame. I don't know how it's made or if there is an affordable COTS unit available. Why not just get the right part to begin with? The entire Hammond vibrato unit (AO-41 or AO-47) is still very affordable on eBay. You guys just don't need to get into a bidding war though! :grin:
The saturable reactor is the key to this circuit. Without it, you got nothing. You can read the theory of operation to see how it works it's magic in the modulator circuit. Here's basically how it works...
Don't think of this as a transformer that's gonna step up or down some ac voltage. Instead, think of it as a device that the primary winding is going to control the impedance of the secondary winding. When current flows thru the primary in one direction, the secondary impedance will be high Z. When primary current reverses directions, the secondary impedance will be low Z. Now make that primary voltage a very smooth, low frequency sine wave and the secondary impedance will smoothly change from a low impedance to a high impedance at the frequency of the sine wave. This secondary is connected such that it switches (actually blends) the plate signal and cathode signal together and passes it on to the next stage. Using the input signal as a reference, the cathode signal will have zero phase shift while the plate signal will have 180 degrees phase shift. The varying impedance of the secondary smoothly blends the 0 and 180 signals together such that the resultant signal has a smoothly varying phase shift. This change in phase causes a change in frequency of the resultant signal.
There's a lot more going on with saturable reactors. Most of it seems like magic.
BTW, I've seen a circuit that uses analog optocouplers to do the same thing as this saturable reactor does.
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I seem to remember reading the opposite, but I very well could be wrong. Still a great song! :laugh:
Thanks, Brad :smiley:
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sluckey,
Thanks. Do you remember where you saw the roach schemo?
Brad :smiley:
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Yes, it was on my computer screen. Can't find it now though. It 'may' have been posted by FYL back in September. Just can't remember.
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Saturable Reactors aye? Are they known by any other names? I have to locate one. What about the soundbyte(s)?
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That's the most common name. They're used in AC voltage regulators, synchro data to azimuth pulse data converters (don't ask). Usually associated with so called magnetic amplifiers. These are the smallest ones I've ever seen.
No sound bytes yet. Maybe over the holidays.
Here's a schematic symbol...
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niiiice! :glasses9:
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Very impressive as usual
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> Saturable Reactors aye? Are they known by any other names? I have to locate one.
Saturable Inductors were hot-poop from 1957 to 1962, and then vanished from the face of the earth.
I'm overstating. Stuff like that was around in 1930s and even 1890s. They lingered past the 1970s, though by that point transistors had taken over many of their jobs.
Each one is designed FOR the job it must do. There were no general-purpose saturable reactors.
Buy the old Hammond. Wire just about like Hammond did or with Sluckey's mods. He added an input booster (organ signal is hotter than guitar signal), and a similar but more-adjustable wobbler (from Fender).
He tried an additional post-boost and removed it. _I_ suspect no post-boost is needed at all; take the last L-C phase network to 250K level pot and out. Loss through the three shifty stage is about 0.4, you want to make-up plus a little more, put a gain of 5 in front. The original Hammond V3(123) post-boost stage is suitable as guitar pre-boost. That makes the same tube-count and 98% the same parts as Hammond AO-47. Just re-wire the post-boost as a pre-boost and then dolly-up the oscillator. (This does mean using 7247 or changing to 12AX7+12AU7.)
He also omitted the dry/wet mixer, which may be interesting to put back in.
> I've seen a circuit that uses analog optocouplers to do the same thing as this saturable reactor does.
The circuit is very general. You can use photoresistors, varistors. or FETs as the variable resistance. The FET variant is VERY popular in some circles.
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sluckey,
I was looking around your site, you do very nice,very neat work!
I went on flea- bay, and found an AO-41, but the guys got it packaged with some other stuff (that I dont need) and wants $99.
WWW and this guy is 20 mins. down the road from me. :huh: Can you belive it? No e-mail address listed either. :rolleyes: So..... I'll have to wait for someone else to put one up for sale.
Thanks, Brad :smiley:
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This is a really beautiful job. I'm overwhelmed by the projects that you guys create. But, I'll have to take my time and build in bits. Hope to live up to the standards that you and your peers provide.
Jack
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I went on flea- bay, and found an AO-41, but the guys got it packaged with some other stuff (that I dont need) and wants $99.
That guy has had that 'deal' running since early October when I started watching. No one's gonna pay that for those units. Just be patient. Your deal will come along. I won't be bidding against you either. Every one I've seen sell during the past 2 months has gone for under $15. Many sellers just call these preamps. Here's a good search string that will pick up most, if not all, of the AO-41s and 47s.
hammond (preamp,vibrato,ao-41,ao41,ao-47,ao47)
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Thanks sluckey.
Brad :smiley:
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Saturable Inductors were hot-poop from 1957 to 1962, and then vanished from the face of the earth.
I'm overstating. Stuff like that was around in 1930s and even 1890s. They lingered past the 1970s, though by that point transistors had taken over many of their jobs.
Each one is designed FOR the job it must do. There were no general-purpose saturable reactors.
Probably not practical to build, but some info that might help someone do so:
www.toshiba.com/taec/components/Generic/M2.pdf
That being said, we don't necessarily build because it's practical.
Also, a short thread from a another unrelated site:
http://www.antiqueradios.com/forums/viewtopic.php?t=35055&view=next&sid=e4ecdbeb0abdd7928ddb43b0ab418424
Jack
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Here are a couple short, poor quality sound clips. The chain is Taylor T5--Warbler--Stuffed Vox--line in at builtin soundcard in computer. The soundcard really loads the amps preamp output and causes a distorted sound. This stuff sounds much cleaner/better without the soundcard connection, but I still don't have a mic. Maybe in a few days...
http://home.comcast.net/~seluckey/amps/warbler/warbler1.mp3
http://home.comcast.net/~seluckey/amps/warbler/warbler2.mp3
This is my first attempt. I used Jet Audio to record. Don't have a clue what I'm really doing. Hopefully this will give you sense of the sounds the Warbler makes. I didn't try any over the top psychedelic sounds. And listen to the Warbler, not my fingers! :grin:
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I seem to remember reading the opposite, but I very well could be wrong. Still a great song! :laugh:
Thanks, Brad :smiley:
Here's a quick thing I found on wikipedia, but I do remember a proper intreview about it that I saw in years past. It is an awesome song....one of my favorites from Cream!
Greg
http://en.wikipedia.org/wiki/Badge_(song)
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slucky,
Sounds great! Very rich, thick, round, and smooth. I'm gonna build one. Just gotta get my hands on one of those saturable reactors. It might not fill a room as well as a real Leslie, but then it sure does'nt weigh as much or take up as much spaceon stage. :laugh: How well does it fill a room? I'd bet pretty darn good. I have a EH, 2 tube pedal thats called the Wiggler (?). It's multi vib/trem/chourse thing, sounds pretty good but I dont think it sounds as good as your Warbler build. Hopefully I'll be able to A/B them for my self some day soon.
I do have a ?..... Of the two (41,47) one has one end of SR grounded, and the other has one end of the SR biased up to 150vdc and no ground. Also, I see that one is (the other end of the SR) plate feed and the other is feed from the cathode. Whats up with this? Why did they do two different ways? Noise, better function of the effect? Also IIRC you built yours to go in an FX loop, but if any one wanted to use the Warbler in front, do you think it would be usefull to wire up that last unused gain stage as a CF?
Thanks, Brad :smiley:
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Thanks for the link SoundmasterG. The sound of the guitar on the bridge has always cut me deep.
Take a listen to slucky's Warbler in action, sounds good huh? Man I've got to build one. Thats one of my favorite type of FX.
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I do have a ?..... Of the two (41,47) one has one end of SR grounded, and the other has one end of the SR biased up to 150vdc and no ground. Also, I see that one is (the other end of the SR) plate feed and the other is feed from the cathode. Whats up with this? Why did they do two different ways? Noise, better function of the effect?
I think it's just a normal progression of the circuit. Maybe it was a cost cutting idea (one less tube) or maybe the 12DW7 was not even around at the time the AO-41 circuit was designed. I've played it with both drivers and didn't notice any difference in sound. The driver is not in the signal path.
I liked the cathode driver better simply because it uses one less tube. The SR is identical in both units though. So if you're gonna totally rebuild, it doesn't matter which unit you get, unless it comes with tubes. I'd lean toward the AO-47 in that case to possibly save having to buy a 12DW7.
Also IIRC you built yours to go in an FX loop, but if any one wanted to use the Warbler in front, do you think it would be usefull to wire up that last unused gain stage as a CF?
My prototype was built on the actual AO-41 chassis, stealing B+ and filaments from another amp. The circuit was left pretty much stock except that I put the fender LFO in it and converted the driver from plate driven to cathode driven like the AO-47. It didn't have enough gain to sit in front of an amp, so I put it between my amp's preamp and power amp (kinda like a passive FX loop). At that point I didn't want to add any more circuitry than absolutely necessary until I was satisfied with the sound effect.
The finished project was intended to be used in front of an amp and included a pre amp and a post amp. The post amp was not needed. I suppose you could convert it to a cathode follower. Might come in handy, especially if you use long cables between the unit and the amp, or want to plug it into a low impedance device like a SS amp.
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Whoa! :tongue9: LOVE that sound! Much better to my ears than trem (which I never liked).
I'll have to keep my eyes peeled for one of those (after the other guys get theirs, of course!)
G
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> one has one end of SR grounded, and the other has one end of the SR biased up to 150vdc and no ground. Also, I see that one is (the other end of the SR) plate feed and the other is feed from the cathode.
Put the two thoughts together. Plate-fed goes up to supply voltage. Cathode-driven goes to ground.
The '41 circuit is sloppy. The large oscillator swing is cut way down, buffered for no reason, then amplified-up again. The plate swing is probably very much like the oscillator swing. Seeing that, the '47 redesign just put the signal to a cathode-follower, saved a bunch of parts.
The back-story may be more complicated. There may be a saturable reactor re-design before the '41 or between '41 and '47, the older SI needed the bigger drive. An improved SI allowed less drive but the tube-works didn't change right away. Recall that unlike guitar amps, church-organs are not SO price-sensitive, the vibrato is the smallest part of a full organ, a few bucks over-spent was not the Big Deal that it would be at Gibson or Kay.
> usefull to wire up that last unused gain stage as a CF?
The output impedance from the R-C-L Y-network is not higher than R115+R114 or 25K. Probably under 20K worst-case, even lower under many conditions. So it can drive a 250K-1Meg output pot and average stage-cable directly. It's really a better source than a guitar, and that works OK.
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I live very close to Lenco Transformer, IIRC Victoria amps has had their tranys made there for a long time, as well as at least a few other boutique builder's. Their an old company (started back in the 40's?). I ran across them yesterday, while doing a search on SR's, to learn more about them. Anyway, their site says that they make SR's, and from slucky's pic's, they look pretty small, so maybe getting a small run say, 25 to 50 would'nt cost very much? Maybe, since all 3 SR's (put togther as 1 unit) are the same, they could make them as just the singles? Get 7/8 sets, might put it in reach. I'd also be interested in trying a 4th stage of phase, like the U-vib has. If they were singles, would be easy to try. When I get my hands on 1, I think I'll bring it over to them and see if they'll give me a quote. If it works out I'd have a few sets to let go to any one who's interested (for my cost only of coarse, no $$$ for me). Might just be dreamin again.
Thanks, Brad :smiley:
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That is a really nice sound! When ever I hear something unusual like that, I wonder how my steel guitar would sound through it.
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Ahhh, ok, Thanks PRR.
Yeah, why not on a steel guitar? IMO it could/would sound great, even if just on some things. Nice "thickener", sure worth a try.
Brad :smiley:
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I wonder how my steel guitar would sound through it.
I can almost hear a steel crying out Sleepwalk thru a vibrato! :smiley:
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Wow! You're getting some incredibly sweet tones thru the Warbler. Very nice.
With respect, Tubenit
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Wow. That's cool.
FTR, if anyone ever wants a good, clean recording of their homebrew gear, you can ship (or bring) it to me, in Durham, NC. Getting to play with our stuff is all the payment I need.
Chris
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http://spacelabstudio.com/
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Sorry for the spam: I have a few of these Hammond AO-41 units if anyone is interested.
PM me for info.
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Hey, I got one! :blob8: Looks good, in great shape. It's stamped, A H-AO-41-1.
Talked with a guy at Lenco, he was very nice. He said there's a good chance they could figure it out with out destroing it. It wont cost any $$$ to do that, and to give me a quote.
He did say might be a problem with using "modern" core matt. because saturation of the core is key for it to function right in the design schem. He also said it's a little different ball game making SR's, that there not as easy to make (if your backwards enginering it), and get them to work right in the design schem. as would be a trans. I'm gonna take it over to see him soon and see what he says. Worth a shot, nothing to loss, can only learn something. Should be interesting.
Thanks, Brad :smiley:
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Steve are you related to Leo? Your info and work quality is amazing!
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You mean Uncle Leo? From Seinfeld? :laugh:
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:laugh: Yes uncle. I just bought a AO-41 unit on Ebay. Did you build the board?
I am looking forward to pestering you about any issues i can not figure out. MERRY CHRISTMAS!!! :laugh:
That warble machine sounds great. The notes and chords ring on and dont decay quickly. I like that
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Yes, I built the board. There's a full size board drill guide on that web page. Just print it out full size and tape to your blank.
Please tell me you didn't pay $99 for that!
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Heck no. I made a best offer and he accepted $50.00. I saw no others on the site and what the heck i have sold a lot of stuff latley on Ebay so im doing pretty good right now. The key is to not go crazy and spend it all. I dont do that. Yeah in the past i have seen them for $20.00
Cool i will print out the template. Does Doug have a blank board that will do?
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Does Doug have a blank board that will do?
Yes. And turrets too.
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***CAUTION***
Hey guys. Before you put a soldering iron on that SR, take a close look. There are a lot of very tiny wires on those terminals. Even the terminals are fragile. If you break a wire, you'll be up s--t creek without a paddle!
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Wow that sure is pretty sounding!. Many thanks for posting those.
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What is Sluckey's homepage?
Dave
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Just click the world icon under my name.
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Sweet. Thank you.
Dave
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Steve do you think this PT i have will do the job? 230-0-230. Heater available current is there.
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Steve do you think this PT i have will do the job?
yes
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Well here we go. Hold on tight. slucky you might have started somethin here. :angel
plexie50, the guy you bought your SR from, I think is the same guy I bought mine from. I noticed from the pic you posted, it had 101 written in red (?) on it by the 6C4 tube. I looked at mine, it has 100 written on it. Hummm.....
So I e-mailed the guy and asked if he had any more that he'd like to sell?
He wrote me back and said "Whats going on? I had that up on e-bay for over a year and nobody ever bought one. Now yesterday I sold one to you, two hours latter I sold another one, and today I have 4 more people asking to buy one". :laugh: Oh well I guess, "When it rains it pours".
Thanks, Brad :smiley:
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Oh my! Y'all run the price up. I got three more. :grin:
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slucky, Not me I got mine for $20 including shipping. :laugh: (Ya know it's against the law to yell "Fire" in a crowded theater if theres no fire, do you smell smoke?) :angel
Me, I've got a guy to see over at Lenco Transformer Co. :grin:
Brad
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He has more on right now. I am tempted but i better just chill and see what happens with the one i already have
http://cgi.ebay.com/2-Vintage-Hammond-Amplifiers-H-AO-41-42-w-Tubes-12-AX7-/170413785490?pt=LH_DefaultDomain_0&hash=item27ad740192
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Yeah, I e-mailed him earlier today, and said I wished he would have told me that he had more, that I would have bought them all. OTOH, I should have asked. He wrote back and said he has one left and wants to hang onto it, but who knows.
plexie, I'm glad you got one too, better you got one and I have one than for me to have two and you none. I can wait, there's more out there. I would like to have a back up though. :wink:
Thanks, Brad :smiley:
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I cant wait to get started on the build process. Going to take my time and find the right chassis to use
The tone is sweet for sure
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He also omitted the dry/wet mixer, which may be interesting to put back in.
Well, that statement got me wondering, so I decided to play around today. I replaced the output level pot with a 250K mixer pot to be able to blend the wet and dry signals. I was expecting to just hear vibrato with the dry signal mixed in. That ain't what happens though! As you blend them together there is a phase cancellation and reinforcement going on that produces a variety of very good tones. Much more versatile than my original circuit. It's a keeper! Here's my revised schematic...
http://home.comcast.net/~seluckey/amps/warbler/warbler_rev1.pdf
Thanks for that tip PRR. And for anyone considering building this, do the revision 1 version. As a bonus, the board shrunk from 12.5" to 11.25".
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hey steve, i know there's a re-vibe out there...but this ckt. looks and sounds a lot more interesting. ever thought about mixing in a reverb ckt.? might be cool... might be a bust, but i'm thinking with an AB763 type reverb, it might just be more lush and versatile, not that it already isn't.
just thinking out loud...
carrion. :wink:
--ISO
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Right after I realized the vibrator unit would work with guitar, one of my first thoughts was to build it into a reverb unit. I dropped the idea when I started the board layout. I would have needed at least 2 more inches of board. And two more tubes. And a bigger PT. And so on... I finally just dropped the idea and decided to keep it clean and simple and fit my 16" chassis.
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I was considering giving a tore-t / warbler box a try. That would give all the tube based guitar effects I can think of all in one box.
Dave
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I don't think you need the tremolo from the Tore-T revibe. The warbler revision 1 gives a very lush sounding tremolo effect as well as the vibrato effect.
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I've got a SR from an AO-41, first one to PM me with a shipping address can have it N/C- Merry Christmas to the forum readers.
UPDATE: It's been spoken for...
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You Sir is good people. Got to love this place. "And good will to man."
Brad :smiley:
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I don't think you need the tremolo from the Tore-T revibe. The warbler revision 1 gives a very lush sounding tremolo effect as well as the vibrato effect.
Great! Any suggestions on how to meld the two together?
I was thinking of just going from the output of the warbler straight into the 6G15.
Dave
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That'll work.
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Man, I was ready to build this thing. I thought I had an old AO41 out there in my collection of madness. Turns out I don't. If anyone finds somewhere to source the thing cheap, let me know.
Dave
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Steve did you try a resistor in place of the choke your using? I just wonder because a resistor sure does give some amps more chime
And im wondering if that chime might be more (vibee)< Thats a new word
Nay. It would probably be to chimey. A choke smooths things out
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Steve did you try a resistor in place of the choke your using?
No. I wanted the B+ to be very clean.
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someone has about a two year head start... :smiley:
http://www.solorb.com/elect/musiccirc/liquidator1/
his construction is nowhere near the quality and neatness of steve's. :grin:
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some of this vibrato technology here was implemented by laurens hammond in a keyboard instrument called the novachord.
it was/is pure genius... a polyphonic synthesizer made in 1939 with 163 valves.
a cool site with some sampling software of a novachord.
http://www.hollowsun.com/HS2/products/novachord/index.htm
click in the jukebox panel to hear some samples - my favorites are titles "nova berlin" and "journey into the mist".
--ISO
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someone has about a two year head start...
That's the guy I mentioned that had already done this. After seeing that site I decided I had to play with it too.
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sluckey,
Did you try playin around with any of the clean and phase 1,2,3, 500k vol. pots,or the "clean phase" switch on the Liquidator schemo? Looks like they may be usefull.
Wonder what you think about them?
Thanks, Brad :smiley:
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I didn't do any of that stuff. I'm sure there are a lot of neat sounds available with all the different pots. Having everything adjustable can also be a nightmare.
EDIT... I just realized that the mix control that I've added (see revised schematic and comments above) is basically the same as his clean switch and pot.
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Having everything adjustable can also be a nightmare.
Because of ??? The dreaded "parasitic oscillations" monster, or just the hassel of a lot more wiring?
I was also wondering why he took the phase 1,2,3, taps to the 500k vol's. off the plates instead of at the 15k, 150pf, 10nf, and SR junction? To isolate the 500k pot, or to isolate the grid, maybe both?
Thank's Brad :smiley:
I can't seem to figure out how to use the insert quote. :BangHead:
{EDIT: quote-fix ---PRR}
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Having everything adjustable can also be a nightmare.
Because of ???
Mainly because you'll spend all your time twisting knobs. Then you'll forget where all the knobs were sitting for that killer tone you found. You'll need a spreadsheet just to keep up with it.
...why he took the phase 1,2,3, taps ...
Hard to say.
I've spent a couple hours experimenting this afternoon. Mixing and matching different combinations of stages together. There were some interesting sounds. I'm not sure how useful some would be. In the end, I put mine back to revision 1 level and buttoned it up. The 4 knobs on the warbler will keep you happy for a long time. I'm gonna call mine done.
I've updated the revised pdf to include a drill guide in case you want to build one. If you decide to do a lot of experimenting please keep us advised.
http://home.comcast.net/~seluckey/amps/warbler/warbler_rev1.pdf
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Yeah too many knobs is a pain.
But I'm thinking, it might be usefull to wire up an on/off foot switch, just for the Fx and maybe a foot operated speed controller, 1/4" jack, might come in handy at a gig. Just a thought.
Anyway, Thank's sluckey :smiley:
Brad
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ON/OFF footswitch is as simple as a switch between Depth pot wiper and ground. Unless you need a true bypass. I didn't wire in a footswitch jack because mine will likely never leave the bedroom.
Speed controller would just be a pot in series with the Speed pot.
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Yeah, I thought it should be easy enough, without mucking things up.
Thank's, Brad :smiley:
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Some things are best kept simple. Thats what makes them great to start with. Reading and listening to that Hammond Novachord is just amazing
So is the Warble in esscence built on the polyphonic principal?
Listen to the music in the Original OUTER LIMITS. I wonder if that organ was used for the tones and scarry sounds
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Pure phase-shift alone is nearly inaudible. I have not clicked your tracks; if the effect is obvious, there's more than just pure phase-shift going on. (It may be sliding overtones away from normal interval-relation to fundamental.)
The "wow!" effect is when you mix direct and shifted signals. As you say "there is a phase cancellation and reinforcement going on".
http://en.wikipedia.org/wiki/Phaser_(effect)
http://www.geofex.com/Article_Folders/phasers/phase.html
Ah: "Magnatone ... never did the addition of the dry signal..."
So you get two effects, semi-Maggie and semi-Univibe.
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I can't seem to figure out how to use the insert quote.
Look at the funny code. There is a {quote...}, the text, and a {/quote}.
Start your reply AFTER the {/quote} (end-quote) code. (Be careful not to lose the {/quote} in editing.)
[quote author=Willabe link=topic=10681.msg98625#msg98625 date=1293133137]
I can't seem to figure out how to use the insert quote.
[/quote]
Look at the funny code. There is a {quote...}, the text, and a {/quote}.
Start your reply AFTER the {/quote} (end-quote) code. (Be careful not to lose the {/quote} in editing.)
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Is this transformer a Nuclear reactor? Not ready to build just yet. Got to round up some other parts. Want to see if maybe i can leave this as is in this case and maybe go external with some controls first. I dont know. Merry Christmas all!
(http://i356.photobucket.com/albums/oo5/plexijtm45/Ta-1.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/Da.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/Caps.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/Nuc.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/Lear.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/Reactor.jpg)
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Steve i see on the layout you have the footswitch. You didnt put it on your chassis did you? I start building friday.
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no
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{EDIT: added start-Quote code - PRR}
Look at the funny code. There is a {quote...}, the text, and a {/quote}.
Start your reply AFTER the {/quote} (end-quote) code. (Be careful not to lose the {/quote} in editing.)
Thanks, PRR.
I'll try playin around with it. I'm getting a little closer.
Brad :smiley:
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Well got started this morning digging and looking for a chassis to work with. I found this old Wurlitzer organ SS chassis and this is what i got done today. Have to wait on the turrets from Doug to build the board. Cant wait to hear this thing /
(http://i356.photobucket.com/albums/oo5/plexijtm45/GetReady.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/Layout1.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/PaintReady.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/Painted.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/FrontComplete.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/BoardBuild.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/Inside.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/BoardDrilled.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/Trans.jpg)
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plexi50, Man, when you said you could'nt wait to get goin on this build , you were'nt foolin! Looks great already!
What did you use to clean and prepare the chassis before you panited it? Looks very nice. Also what did you finish paint it with? Any/what type of primer? How many coats of each?
Thanks, Brad :smiley:
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I just used steel wool to get down to a clean finished look and then used acetone to clean it real good. One coat of light gray auto primer and 2 coats of Flat white paint. It's all i had laying around. If i look back behind me and look at it i am starting to wonder where it came from. Did i do that? If you had seen the inside of the chassis before i gutted it you would never think it was the same chassis
Glad i keep a lot of junk. Pac Rat. I wonder if Steve is still tinkering around with his. Or if there will be any other revisions (tweeking) That transformer is to cool :grin:
Also saw a guy on Ebay that is selling 4 available Hammond A0-41 & 47 units for $100.00 each. Dam cat is out of the bag. I want to get 2 more just for GP if this one psychs me out nicely. But not at $100.00 each
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Plexi50, just a heads up before you load turrets. You have the transformer mounted on the bottom side of the board in the pics. The transformer is fragile. I'd let that be the last thing to install on the board.
I'm done with mine. I did change the mix pot to a 500K-L to give some more isolation between the dry and wet signals. I can't hear any difference from the original 250K-L though.
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Plexi50, just a heads up before you load turrets. You have the transformer mounted on the bottom side of the board in the pics. The transformer is fragile. I'd let that be the last thing to install on the board.
I'm done with mine. I did change the mix pot to a 500K-L to give some more isolation between the dry and wet signals. I can't hear any difference from the original 250K-L though.
Yes good idea. I just wanted to see if all my drilling matched up. Perfect template. Is your transformer flush mounted on your board? There were two nuts on the bottom of transformer mounting screws acting as stand offs. I removed them because the screws were not long enough to go all the way through to the backside of the board. I can see you really need longer screws to have that nut on the bottom to keep the transformer top half from pulling down and possibly breaking it as you tighten the two screws down on the board
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$100 EACH! Old, Old, Ted Nudgent, Tooth, Fang, and Claw, "Well Here We Go"!
Thats why I called a transformer company. I'll go see them after the first of the year. Might just be a "blip" in the "market", but who knows?
AND IT'S ALL SLUKEYS FAULT !!!!! :laugh:
Brad :angel
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The guy on the Liquidator page link is two years ahead in this. But in all honesty i think Steves layout is so clear and precise that it may be the straw that broke the Hammonds back. Im sure there will be plenty of them around cheap. Just have to look everyfew hours. Thats a pain in itself
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Yeah .... BUT !!! "Dougs" site ("Our Fearless Leader", remember Bullwinkell & Rocky?) has what 2k plus members? Not including guest's? Words gonna spread.
AND !!! The guys here are not "foolin" around. "GIVE ME MY TONE, I'LL BUILD IT MYSELF" !!!! :laugh:
But..... PRR did say, we can use more than one "coupling" agent to acheive the same goal.
Maybe when he and his good girl Molly, whose's riding shotgun with him, get done plowing, he'll have time to tell us more?
Hey, I grew up in Chgo. so I'm no stranger to snow. When it fall's, and it does, and it's still gonna,(no matter what Vice Pres. Gore say's) clearing that stuff out of the way comes FIRST! People have health problems, need to get their meds, need food, water, ect..... . Please remember to ALWAYS IN COLD or HEAT extrems to check on ALL your older and/or disabled or ill neighbors who might need help from you. I remember having to come out more than a few times through the years to hand shovel out our side St. that we all lived on. It was always the ---HEAVY---- WET---- 6" to 8"s of very heavy, not the light powder for skying. Dad was right," Who's gonna shovel out the block if We don't". It was kinda fun, as long as dad was their too.
Anyway Thanks, Brad :smiley:
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Here's another one...
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rt=nc&nma=true&item=150498597286&si=%252BgX030GSbhos6g1HhHwPW59S4Oc%253D&viewitem=
Oh, wait. I already bought that one! :laugh:
If you guys will be patient and don't buy at these ridiculous prices, the price will go back down. I don't think this item will be a big hit.
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Here's another one...
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rt=nc&nma=true&item=150498597286&si=%252BgX030GSbhos6g1HhHwPW59S4Oc%253D&viewitem=
Oh, wait. I already bought that one! :laugh:
If you guys will be patient and don't buy at these ridiculous prices, the price will go back down. I don't think this item will be a big hit.
I just got another email from the person selling them on Ebay. He has two different accounts so the ones you see now are his but in his wifes Ebay store. I got mine from him using a best offer at the time. He is holding out now firm at $100.00 a piece. There will be plenty more to come on soon at $20.00
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Boy this is quiet a job. The hard work is done. I ordered the wrong parts and wound up with eyelets but it worked out very well
All i have left to do is wire up the PS,pots and tube sockets
Oh yeah and the PITA heater wiring. I hate wiring heaters
The under board wiring sucks the life out of you
(http://i356.photobucket.com/albums/oo5/plexijtm45/Warbler1.jpg)
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So close. I will finish it up tommorrow. Visine time /
(http://i356.photobucket.com/albums/oo5/plexijtm45/Sockets.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/InsideAF.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/Pots-2.jpg)
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Looking good!
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I thought those .47µF caps were very small. You have installed .047µF instead. Try it and see if you like them. If it sounds too thin or bright, put the .47s in there.
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Opps! I was bound to do something like that. Maybe i can use the caps from the old hammond board. I dont have any here except for them. Thanks for catching that!
Ok here are the right caps. They look good too! I have to remember that decimal before the numbers
(http://i356.photobucket.com/albums/oo5/plexijtm45/47.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/InsideCapCorrection.jpg)
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Ok i am all wired up and finished minus one wire connection
Steve is the 0.047 cap from the Mixer pot going to another switch?
Vibrato = open?
Chorus = closed?
All i have left is a single wire to connect from the .01 cap to what i believe is a switch
I only see one switch on the front panel of your actual chassis build on the Speed (rate) pot
I fired it up and my voltages are:
A-330 VDC -12AU7
B-326 VDC -12AU7
C-248 VDC-12AU7
D-172 VDC-7247-12DW7
E-312 VDC
Node C from your voltages should be 124-5 vdc / I have not plugged into an amp/guitar just yet
(http://i356.photobucket.com/albums/oo5/plexijtm45/HTRS2.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/1Wire.jpg)
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Ok i am all wired up and finished minus one wire connection
Steve is the 0.047 cap from the Mixer pot going to another switch?
Vibrato = open?
Chorus = closed?
Yes. Look at the revision 1 layout.
http://home.comcast.net/~seluckey/amps/warbler/warbler_rev1.pdf
All i have left is a single wire to connect from the .01 cap to what i believe is a switch
That's the fast/slow range switch for the vibrato rate. It's on the left side of my front panel.
I only see one switch on the front panel of your actual chassis build on the Speed (rate) pot
I didn't use a Vibrato/chorus switch on my build. The cap from my mixer pot goes directly to the board on mine. Remember, you're building from the improved revision 1 schematic. If you don't have room for another switch next to the mixer pot, just wire the cap straight to the board IAW the layout. You don't really need that vibrato/chorus switch but it is a convenient way to mount that .047 cap.
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Also gotta find out why your node c voltage is twice as high as mine. Measure all tube voltages and post.
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Ok Steve. I have the Mixer .047 cap wired straight to the board
All voltages are good except for node C
Checking tube pin voltages now
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I did a voltage check on V1 V2 V3 and all voltages look good with no fluxuations
I am assuming since Nodes A-B-D-E are reading correct on the filter caps that these nodes are proper
I had to turn all the pots to the off CCW position to get a steady reading on V1 V2 V3
BUT! V4 is all over the place and the voltages are pulsating up and down. Here are those voltages:
V4 VDC
Pin 1=249
Pin 3=14.80
Pin 6=170-195 pulsating up and down
Pin 8=1.380-1.450 pulsating up and down
I did connect to guitar and amp but there was no effects to be heard. Just plain amplifier tone
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OK, I'm home and can do some troubleshooting with you, so if you can, stay online. I have my unit open so we can compare readings. It sounds like yours is 90% functional, but I don't like where we may be headed. Since the voltage is off on the plate of cathode follower V4A (pin 6) I'm suspecting a problem in the cathode circuit. Here's the plan...
Turn the unit off to make some resistance checks.
1. Check resistance of V4 pin 3 to chassis ground. Put one meter lead directly on the tube pin 3. Should be 1260Ω. If you measure 11K then the primary of the SR is open. Let's hope you forgot the jumper wire from terminal 1 or 7 on the SR. (refer to the layout).
2. This step depends on your findings in step 1. Cross your fingers!
Just a little extra info... The primary side of the SR should read 260Ω between terminals 1 and 7. It's actually 6 windings in series. There are tiny wires on all terminals 1 thru 7. All it takes is one broken wire to make the SR useless.
Good luck. I'll check back often and if we happen to be online together, I'll stay with you til we know what's wrong. I don't think it will take long.
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Ok Steve i am reading your last post now. I just posted all the preamp voltages:
All preamp tube VDC voltages are as follows:
V1 VDC
Pin 1=145
Pin 3=7.85
Pin 6=131
Pin 7=28.50
Pin 8=45.00
V2 VDC
Pin 1 =130
Pin 2=28.50
Pin 3= 45.00
Pin 6=128
Pin 7=2950
Pin 8=46.00
V3 VDC
Pin 1=68.00
Pin 2=.017
Pin 3=2.275
V4 VDC
Pin 1=249
Pin 3=14.80
Pin 6=170-195 pulsating up and down
Pin 8=1.380-1.450 pulsating up and down
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Stay online and do the resistance check.
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Ok the resistance check shows the SR open and i am reading 10.85K off V4 pin 3 cathode to chassis ground
Checking routed wires from SR transformer to board now
*All wires from SRT are connected to there board points correctly
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OK. Put your ohm meter leads directly on terminals 1 and 7 of the SR. Still reading about 10K? If so, that's bad. Take a flashlight and look closely at all the tiny wires on all the terminals on that side of the SR. Does everything look OK? Pay close attention to the terminals that you have been soldering on.
What you got?
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Yes SRT reads 10.80k across 1&7
Been testing all the transformer wires and found a blck one that is not connected continuity wise
Soldering back on now. It looked solder on but there is a white goo residue from old age
Back in minute
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Ok got it! One tiny black wire was not soldered good enough
That was the problem with the higher voltage on node C
Node C now 121 VDC. Man this is awesome diagnostics
So i plug the guitar into the input and the other jack Mixer into the amp input?
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Yep. I'll stay online to see if it goes well. Turn the mix control max CW for maximum effect or turn it max CCW for dry signal. Then bring the depth control up and set the rate as desired. Let me know what happens.
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Ok hooking up now /
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Wow! It sounds cool! Real sweet sweep. Rate,Depth & Input pots working good
There is one issue. The mixer pot seems to not do much until it is near full CW position but i understand that better now between a dry and wet signal
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Mixer pot needs to be a linear pot. That would be Alpha type "B". You didn't use an audio taper (type A) pot did you?
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Yep thats what i did. I have to find a Linear pot or order one. I think it sounds real nice. I need some time to play with it and hear it after i replace the mixer pot. Thanks Steve for your help again. Great little vibrato. This was an intense but fun project
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If you have to order one, get a 500K linear.
Enjoy. You're the fastest builder in the West, err, South! :laugh:
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plexie50,
ALL RIGHT! :toothy2: now you and your gittar got it made in the shade with the cool soundzzz spinnin round :toothy12: and round :laughing6:
How about some pics of the top side of the chassis? When your done taken your new girl for a drive of course. Under side looks great, you do very nice work.
You guys had me scared for a little while there, glad it worked out after all! That was better than reality TV. :laugh: I happened to come on line just when slucky said he just got home.
Brad :smiley:
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500KL it will be. Thanks. Thats why im burned out a little. Between repair work i dont get many breaks to build my own stuff like i used to. This old 1936 Philco was fun to recap. Theres a good market for a tube vibrato. Im wondering how this would compare to the maggie after i change the Mixer pot. The maggie vibrato is just very sweet
Yeah Willabe it was a CRASH course all the way. I say we delete this thread and market the thing. :laugh:
I love what i am hearing. It's real and it works! I need to construct some kind of cab for this
I think i have one in the garage that i can modify / Im gona go look
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Theres a good market for a tube vibrato. I say we delete this thread and market the thing. :laugh:
Sounds good to me! YES SAYS I !!! Let us dream a little, shall we ???......
sluckey can be Pres./CEO, plexie, you can be VP, and I'd just be glad to be factory floor manager, ie.... I sit at a table and solder/wire'em up! :laugh: Have I said that I don't do well in these cold/overcast NW of Chgo. winters??? :sad6:
I'd still like to hear it with a 4th stage, and a separate dry out for using two amps, left/right to realy spread out the sound on stage. Would give it something to work against itself as a referance point, doppler sound --0-- start point, should "fill" a room much better.
Talk to you guys later.
Brad :smiley:
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sluckey can be Pres./CEO
Thanks, but naw thanks. You guys run with it. I got a day job and I ain't gonna mess up a good hobby. :grin:
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sluckey can be Pres./CEO
Thanks, but naw thanks. You guys run with it. I got a day job and I ain't gonna mess up a good hobby. :grin:
I can hear the throngs of gittar players who are looking for "THE WARBLER" sound calling out ...... slucky, slucky, ...... :laugh:
All kiddin aside, you know I'm just pullin your leg. I think your a good and generous man, wise too, 5000 + posts proves it! :wink: Thanks slucky for sharing this FX build and all that you share with all of us.
Brad :smiley:
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Just think: Some where in a warehouse there is a box of 5000 SRT's and no one knows what they are :cry:
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Right on tube builder man, I belive your right !!! :wink:
Hey, we will find them !!!
Brad :smiley:
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Read this link: I think it is refering to the matching transformer we are using and the principles of it's function
http://www.nshos.com/hammond9.htm
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That's describing the older motor driven vibrato scanner/delay line. If you want the theory of the circuit you are using, read this...
http://home.comcast.net/~seluckey/amps/warbler/Hammond_AO-41_and_AO-47_Vibrato_Units.pdf
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Thanks. It's all good reading
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Well, I got one. Its Sunday morning. I have all my chores done, so I may just get started on my box today.
Here is North East Texas, global warming has caused abnormally frigid temperatures, and at this moment there are conditions just shy of whiteout.
The snow has been falling for about an hour and it shows no signs of stopping.
I guess its time to build tube circuits.
Dave
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Dave, if you're gonna use my layout, you may want to download the latest revision 1 file which has 2 minor changes since plexi50 built his. I eliminated the (mostly useless) vib/chorus switch and mounted the .047 cap on the board.
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Thank you sir. I will download the updated schematic.
At one point while reading all this, I noticed that you mentioned that the circuit was a little dark.
Have you experimented at all with remedies for that?
Dave
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Adding the mixer control seemed to take care of that.
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Cool. Thanks.
Dave
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I had to make a revision of my own. I cut and removed a small amount of the circuit board and relocated the SRT to the chassis itself. It was sticking out of the bottom of the small chassis i used. I didnt want anything to happen to that SRT
Also i think i want to try a 300 ohm resistor in place of the choke and see if i get more shine. The Maggie did not use a choke in it's amplifier circuit and like a few other amps like the Ampeg Gemini II i really liked the crystal clarity (shine) of the resistor vs the choke in those amps
I have a good feeling something great is going to happen in tinkering with this project
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plexi50, Great job!
Find any new sounds, or notice any thing new sound wise you had'nt found/heard before?
Thanks, Brad :smiley:
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I put a plexi bottom plate on mine just to protect the SR.
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plexi50, Great job!
Find any new sounds, or notice any thing new sound wise you had'nt found/heard before?
Thanks, Brad :smiley:
Yeah i was playing with it a few hours ago and i noticed a spot that sounded really cool. See i still have 250KA audio pots for the mixer and depth. I will have the 500KL linear pots this week and that should be even better in bringing out a better sweep and funkability! I think this project is the amps meow!
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Dave, if you're gonna use my layout, you may want to download the latest revision 1 file which has 2 minor changes since plexi50 built his. I eliminated the (mostly useless) vib/chorus switch and mounted the .047 cap on the board.
I was thinking of doing the same thing and using the switch on the front for the power on/off
Scratch that comment / I got the fast/slow switch mixed up for a minute
I already have the vibrato/chorus cap straight to the board :rolleyes:
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Well, I didn't get around to it. I'm not used to blizzards in this part of the country, and I thought I could just hang out and build this thing today. Instead, I was on the roof of the barn trying to get the snow off so the tin wouldn't buckle under the weight. Who knew?
Saved the barn.
My horses were all encased in ice. They didn't seem to mind much, but my wife was about to lose her mind because the poor horsies were cold.
I thought she was going to bring them in the living room.
Quite a day when all I wanted to do was build a tremolo device.
Maybe I'll get another chance one day soon.
Dave
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If nothing else, I had a little time to think about the build and it led me to this.....
I plan on building the Warbler right behind a 6G15 reverb circuit.
It seems to me that doing it after a 6G15 eliminates the need for the input stage that Sluckey added.
Am I right about that?
Also, I've never used a 6G15 in an effects loop before but this is my plan for this unit. So, how well does the 6G15 perform in an effects loop?
Dave
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Steve i have a question. Changed the Mixer pot to 500KL. After getting some time to play with it i notice i have a heavy pumping wooshing action at amp idle before playing. Does yours do this? I heard your sound clips and your appears to be silent until used. Whatcha think?
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Mine does the pumping thing too if I have the depth control cranked real high. Almost sounds like a helicopter. I just back off the depth until the pumping stops. I can still hear the background amp hiss changing at the vib rate, just like with many tremolo circuits.
See that 2.2meg resistor that connects to the top of the depth control? I chose that resistor value (by experimenting) to allow the vibrator to have a little pumping with the depth turned all the way up. You should have heard it with a 1meg! Way too much! If you increase the value of the 2.2meg, you will decrease the pumping effect, but you will also limit the strength of the vibrato. You can accomplish the same thing by just turning the depth down some. Mine has plenty of depth for my ears without being turned all the way up.
You can probably smooth the pumping some by increasing that .047µF cap connected across the depth pot. And that 10K resistor in the cathode of the driver tube may have an impact on the smoothing of the vibrator. That resistor was factory selected on the original AO-47. I would think that decreasing that resistor would decrease the pumping (and the strength) of the vibrato.
If you experiment with this, post your results, especially if you find an improvement.
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I would like to get a tad more glassy shine but heres what i did today:
I put every else aside this afternoon. Here is what i did and i really like the change though it was minumal< (Is that spelled right?)
I played with the 2.2Meg resistor and changed it to a 3Meg
This brought the thump down a bit but still plenty of thump to be had if wanted
I think the Depth pot (intensity) works better and allows for a slower transition. JMO
I have a Magnatone customer that uses his M10 Vibrato for vocals only. Another reason i was really interested in this project
I reversed the Mixer outer terminal leads from your layout and now have CCW off and CW gradual mix
The (2) 500K pots made all the difference in the Mix and Depth pots balancing the controls out perfectly
I dont think there is any need for any further improvements other than to put the On switch on the front panel in place of the Fast/Slow switch which is really not needed
Happy results!!! :grin:
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The (2) 500K pots made all the difference in the Mix and Depth pots balancing the controls out perfectly
I never meant for you to change the depth pot to 500K. Only meant change the mixer to 500KL. That explains the increased thumping in your vib.
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I will put the 250KL back in this week sometime. I just changed V1A cathode cap to a 2.2uf. It is still plenty full and depth defined just not as dark
Will raising the value of the 150pf caps give me more shine or is it the .47 caps that i need to try different values to brighten up?
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Tried the .047 caps. They sucked. Lacking warmth. .47's back in. Bridged 470k across 500K wiper and outer pot terminals and have 248KL. Close enough and works better. I want to slow the rate down just a hair more. You have created a Vibrato junkie! :laugh:
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Vibrato junkie!
And I remember when everything you touched became a plexi. You've come a long way! :wink:
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Boy your right about that. It has been a wild journey. I could have had my own cereal brand / plexi O's
I paralleled a .022 cap across the exhisting .022 rate cap but that was too slow. I tacked a .0047 across the .022 and nice
I paralleled the .01 cap and got the same results with the speed rate but just used the .022 as it was more convenient
I think though that the .01 to the rate pot is where i should have put it
Something in the rate cap change itself has made the vibrato blossum a bit more even when compensating for the slower rate by CW pot
I see what i did. I changed the plate coupling value of V4B. It did something nice. I wouldnt think it would have slowed down the rate though
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Something in the rate cap change itself has made the vibrato blossum a bit more even when compensating for the slower rate by CW pot
Ahh, :happy1: Very interesting.
Brad :smiley:
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See what i typed above. Not looking at the Layout at the time, i changed the V4B plate coupling cap value. But the rate slowed down so thats where i put it. umm! :huh:
As well maybe changing the .01 cap going to the 2.2Meg resistor would also change the tone of the depth and buffer the pumping action a bit. My 500KL pot in the rate position is down to 248KL using a 470K resistor across the wiper and outer pot terminals
All said this thing is fun tweaking. Im looking for and getting a more active so to speak (EQ) and so far the little changes are producing that for me
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My 500KL pot in the rate position
Huh? I used a 3meg pot for my rate (speed). Put the right pot in and you'll probably be happy with the slower speed. Bigger value equals slower speed.
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Im sorry i did it again*
My 500KL pot in the Depth position is down to 248KL using a 470K resistor across the wiper and outer pot terminals
I am using a 3Meg RA for the Rate pot
On the board is where i made the parallel cap addition of .0047 to the .022
Im keep getting the rate and depth pot mixed up
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Just wanted to report that I finished this delightful project today. I used the board and some of the circuitry from the original Hammond box, then added the LFO and input amp using terminal strips and empty parts of the board. It fired up nicely and works fine. The only problem I encountered was with the tube sockets I bought from Antique Electronics - two of them had jammed holes, which I didn't notice until the whole thing was wired. I'm not sure if they were defective as delivered or if solder wicked up in the holes during construction.
The sound is better than I expected - very useful for modern jazz (a la Scofield or Metheny) or as a sub for chorus or tremolo in rock tunes. I'm going to ask my bass player to try it next.
I did find the mix and depth controls to be somewhat duplicative sonically, even though they perform different functions.
Anyway, tnx for the nice idea.
Bob
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Well, I'm glad it wasn't me who bumped this thread into existence again. Not that I don't like the thread, I do, but oh well get ready for prices to skyrocket again.
Now that the cat is out of the bag again, here is what I have to add.
I have built it too and I have these observations.........
PRR speculated that it could be built using only 3 tubes. Eliminating the final stage (which functions as an output boost) and reconfiguring it as an input boost. He couldn't have been more right. Eliminating the last stage, from my tests, had no noticeable effect. Reconfigure........ I left it as is and ran the input signal straight into it as is. The output then became my clean signal and it worked perfectly both as a guitar input and running with an effects loop.
On mine, there was some disparity between the extremes of the mixer pot because there is some loss thru the circuit. I found that this was easily compensated for by using a 25/25 bypass cap on the first (original) stage. I thought at first that it might cause problems because the cathode had series resistors tapped in the middle for some grid feedback and one of the SR leads attached there, but no, the only effect was a positive one.
The cap that Sluckey uses as a slowness boost for the LFO is interesting. I changed mine to .1uF. The frequencies still overlap, but I get some really slow oscillations with .1 and I thought why not have the range be as wide as possible.
Next, I did a lot of tweaking and fiddling, and the biggest thing that stood out to me was that this thing (with certain tweaks) makes a very convincing wah effect, but it oscillates by means of the LFO circuit. It would be very interesting if someone could come up with a dynamically responsive LFO circuit, we could have this thing double as an autowah. Just a thought.
Enjoy.
Dave
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Can you show your changes in circuit and possable part changes? I know it is quit a detailed layout Steve made. For a guy that works 9-5 he sure puts a lot of THINKING which i lack sometimes into his layouts and schematics. I would not be where i am at today without his and many others teachings. I may be having a little trouble with mine between the mixer and depth pots. I have a cutoff point before full CW on either pot. Like grid cutoff. The only part that i used that differs (1K) is a 1.2K resistor on V4A cathode
I have not had the tme to tinker with it latley. But over all it does a nice job once i can set the mixer and depth pots
The mixer and depth pots though are very sensitive and quick to go into cutoff or should i say a dry signal not leaving much pot functionality
Im sure i need to go over it again with a fine tooth comb
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These are the changes (the ones I can think of off the top of my head) in a very rudimentary mutilation of Sluckey's schematic.
I am not able to look at it right now, but I will see if I can get a peek at anything else when I can.
I will say that I messed around with the voltages a little bit, and fenagled voltages that mimicked both the original hammond circuit and the fender LFO circuit.
Dave
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Glad to see y'all still have interest in this project. Keep the tweaks coming. I'm taking note. :smiley:
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I just remembered something else I did.....
The .47 coupling caps have DC on both ends whether they are leaking or not. I suspected mine were leaky, but I wasn't sure so I changed them out.
I didn't have any .47 caps with a voltage rating high enough, and in an attempt not to have to buy any, I changed them for what I had on hand.
I didn't want to go with 1/10th the capacitance, so I went with more capacitance.
Mine are now 1.2uF film caps.
No perceivable difference in tone.
Dave
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Found one of these on a shelf in the basement while doing some pre-move sorting...
Don't know if its an AO 41 or AO 47...
If any one is interested, i', not looking to get some exorbitant price...
(http://ericallanmusic.com/files/images/ao41.jpg)
flocentblack aaaaattttttt yahoo dot com
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Found one of these on a shelf in the basement while doing some pre-move sorting...
Don't know if its an AO 41 or AO 47...
If any one is interested, i', not looking to get some exorbitant price...
flocentblack aaaaattttttt yahoo dot com
it is the AO-47. this is good. :smiley:
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Well I just came back from Lenco Transformer Co. Talked with a salesman and after he looked at it for a while, he said off the top of his head he thought for a run of 25, maybe $40 a - single - inductor, each unit has 3, so $120 :w2: , and thats if they can even wind them. He said they sometimes used a very fine wire, smaller than what is used on guitar pups, on the coil windings. Not the center coil but the 2 end coils. He also said he thought the lams. were nic. and not steel which cost's more. He did find a company that still makes them.
I left it there so one of their techs can look at it and do some tests to figure out for sure what it is and if they can make it. He said that they wont damage it. :dontknow:
I'll know more late next week.
Brad :think1:
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> The .47 coupling caps have DC on both ends
One end is at plate voltage. One end is at cathode voltage. Why a problem?
> now 1.2uF
Feeding 15K, we want 0.6uFd for 20Hz response. Hammond knew 20Hz was not needed, used half uFd. Guitar is shorter bass than organ, 0.2uFd would be fine. You "spent too much" for 1.2uFd, can pass 5 times deeper bass than guitar needs. Like I put a 9x3 wood block where 2x4 would have carried the toilet-load... it's what I had handy, cheaper than going out for 3 feet of smaller lumber.
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1. Why a problem?
2. Feeding 15K, we want 0.6uFd for 20Hz response. Hammond knew 20Hz was not needed, used half uFd. Guitar is shorter bass than organ, 0.2uFd would be fine. You "spent too much" for 1.2uFd, can pass 5 times deeper bass than guitar needs. Like I put a 9x3 wood block where 2x4 would have carried the toilet-load... it's what I had handy, cheaper than going out for 3 feet of smaller lumber.
1. I didn't say it was a problem. Just that it its akward to check for leakage.
2. I didn't spend too much. I had those caps laying around. I wasn't going to use them for anything else, so I really saved money.
Dave
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sluckey,
Do you think we could put in a passive FX loop with a couple of volume pots, from the output of the 3'rd stage shifter and back into the 1'st stage input? Then insert a delay pedal and send just the wet signal back to the input, kind of like the regeneration control on a flanger?
Might be very interesting to play around with. Maybe with a short delay of say 10 to 40 ms it would make it even more lush?
OTOH, maybe it'll just feedback/freake out and make noise, but it's worth asking.
Thanks, Brad :think1:
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Do you think we could put in a passive FX loop with a couple of volume pots, from the output of the 3'rd stage shifter and back into the 1'st stage input? Then insert a delay pedal and send just the wet signal back to the input, kind of like the regeneration control on a flanger?
Absolutely! Sounds like a good experiment for you to try. I don't have a clue what might happen or what sound you may be chasing. Could be a real tone generator. Let us know what happens.
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This thing is really cool. Never owned or serviced a Magnatone. Looks like a great project. I also liked the looks of the finished product.
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Hi ThermionicEngine,
Did you hear the sound bits sluckey posted? They sound great! Much thicker and more fluide than a Maggie, IMHO.
Look back thru the post and you'll find them.
Yeah, hats off to sluckey, not only is his work very, very nice, but he posted the schem and layout for the chassis and eyelet/tag board!
Absolutely! Sounds like a good experiment for you to try. I don't have a clue what might happen or what sound you may be chasing. Could be a real tone generator. Let us know what happens.
I was thinking maybe if you send the output signal back in, slightly delayed, it would re-phaseshift the signal again --but-- now the sine waves of the 2 signals would line up at a different time. The peaks would be at a different point time wise and this would cause the signal to thicken. Maybe even act/sound somewhat like a 6 stage phaseshifter with out doubling the whole thing. :think1:
I'll let you know when I get to it what it sounds like or if it even works.
Thanks, Brad :icon_biggrin:
{EDIT-- untangled quote -- PRR}
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Thanks, PRR.
Brad :icon_biggrin:
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i was going to base my LFO on a Exar XR2206 or the Maxim MAX038 function generator IC. alas though i've been thwarted again and no good intention goes unpunished. BOTH devices are obsolete and out of production. NTE still lists a replacement for the Exar 2206 and my local fry's still has a few in stock, but i'm NOT playing at 30bux a pop.
why the sand state? thought it might make some cool noise with a triangle, sine and square wave LF source. looks like i'm gonna have to roll up my sleeves and roll_my_own with op-amps.
oh well... :dontknow:
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thought it might make some cool noise with a triangle, sine and square wave LF source.
I played around with that idea too, but just never did it. I was gonna use my HP 3310B function generator for an external modulation input. It would only require an input jack and maybe a resistor. I may do that yet. Thanks for the reminder.
Are you gonna build this? Got a saturable reactor?
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Are you gonna build this? Got a saturable reactor?
yes, and yes. i have two. a forum member made me deal on a AO-47 i couldn't refuse.
if i $crew one up, i have a backup. :icon_biggrin:
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It would only require an input jack and maybe a resistor. I may do that yet. Thanks for the reminder.
you should - if'n yer a-waitin' on me... :BangHead: ...you may be waiting a while. i have nearly 3million bux worth of routers and fiber optic transport equipment to install all over the state within the next year. it is likely that very soon i will be scarce here and my thermionic experimenting slowed considerably.
http://www.utexas.edu/news/2010/12/16/regents_support/
:dontknow:
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Sounds like a nice contract. Do you do fiber work too (I mean connectorizing)?
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Well you cant count your chickens before they hatch, but I just talked to a guy who might have the spec/order sheet for the SR --and-- might have a small number of SR's layin around. :happy1:
Have to wait and see. :w2: He said he had to look up the part # to find the part and any info he would have on it. I gave him the # off the Hammond schem. of SR 1,2 and 3, but that might not be it. I have mine at a transformer company right now getting checked out, so I could'nt look at it to see if there's a part # on it. Which still might not be Hammonds . I don't recall seeing one on it. Do any of you'rs have a part # on it that you recall?
Brad :think1:
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Sounds like a nice contract. Do you do fiber work too (I mean connectorizing)?
we do some but usually only in emergency situations. we have an old fusion splicer that's a chore to use. nowadays we mostly contract our FOC work.
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don't recall seeing one on it. Do any of you'rs have a part # on it that you recall?
i have one AO-47 unit that looks like it's brand new... i'll check it tonight when i get home. honestly, i think that all you're going to get off the hammond part is an OEM number.
--pete
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Thanks Dummy Load, and I think you'r right about it only being an OEM #. If he's got the part and/or some info on it, he'll find it.
Oh well, have to wait and see. How long it'll take for him to just to get to it and look around for it, who knows. :dontknow:
Brad :think1:
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What is Sluckey's homepage?
Dave
http://home.comcast.net/~seluckey/amps/index.htm (http://home.comcast.net/~seluckey/amps/index.htm)
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Well my guy came thru. :happy1: He's putting 8 SR's in the mail to me. He said there brand new and have never been installed. He also said he thinks the last time he saw the price list for them they were $55, and has only sold maybe 4 of them in the last 30/40 years, all of which were international sales.
He still has'nt had a chance to look for any paper work he might have on them. If he has any it's in another warehouse and will get back to me after the next time he goes over there.
Brad :icon_biggrin:
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Well I got them the other day and they all test good for coil resistance. Look to be the same as the 1'st one I got a hold of. :icon_biggrin:
I've been thinking about if you could use the unused 12AU7 triode as a 4'th stage of phase shift, but wiggle the cathode with a light bulb and LDR like in a Uni-vibe.
Could I drive the bulb with/off the LFO driver, maybe pin 2, of VA4 would keep the two in phase, but still isolated? Or do they even need to be isolated from each other? Would they be/work at the same speed? The light bulb is susposed to give a slighty different shape to the signal wave form because the fillament heats up/cools off at a slightly different speed.
Since there's an unused triode left over, I'd like to try to put it in as the 1'st phase shift stage to feed the next 3 stages the slightly differently shaped signal wave to work with and see/hear what it sounds like. Do you think this can be done?
Also, how much current are the 12AU7's biased for? RCA book says they can eat up as much as 11.8mA per triode from the high voltage supply.
Thanks, Brad :icon_biggrin:
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I think you can probably do it. Just jump in with both feet. I don't really have any specific ideas.
Could you take a pic of your SR? I'd like to see what it looks like. Is it 3 SRs on a common form like the Hammond?
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Could you take a pic of your SR? I'd like to see what it looks like. Is it 3 SRs on a common form like the Hammond?
Yes, it's about time I learn how to do that. I'll talk to my neighbor tonight and see if he will show me.
I was able to get 8 SR's and there all the same. Exactly like the 1'st one I bought and I belive, from the pics in this thread, are the same as all the pics. Yes, there 3 SR's on a common form. They are Hammonds. The guy I bought them from was the head tech at Hammond for many years. When Hammond was going to sell to Susukie music, they offered him the option to buy all of there parts stock, and he took it. These were spare parts and he does'nt belive he has any more, but who knows? I belive he's still got a big storage building full of parts, so he might run across a few more. I told him that I was hoping he had a big box full of them, like 50, 100, maybe 250 of them. He laughed a little and said he does'nt think he ever had more than dozen. He's still looking if he might have any info from Hammond on them, like maybe even the order/spec sheets and who Hammond had make them. Have to wait and see. :dontknow: He sold them to me for $15 each, which I thought was nice of him. He could have asked for more, he did say he seemed to remember the last time he looked at the book price list they were $55.
Now that I have a few to play with, I think I'll try a 6 stage shifter and see what happens. :think1: I can make a few for friends and keep a couple for myself.
How much plate current do you think the Warbler wants to draw the way you have it biased up?
Thanks, Brad :icon_biggrin:
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Here's the coil resistance readings I took on the new RS's I got.
Brad
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How much plate current do you think the Warbler wants to draw the way you have it biased up?
The easiest thing to do would be just stick a 1Ω resistor in the PT center tap and just read the actual B+ current. However, it would be a week or so before I could do that.
Another way would be to calculate the plate current for each tube and then just add them all up. For example, V1A has a 100K plate resistor, 155v on the plate and node E is 312. So, that 100K has 312v-155v=166v across it. So, plate current must be 166v/100kΩ=1.66ma.
V4A is a little trickier. You have 4.4v across a 1K in series with the 260Ω resistance of the SR (just ignore the 10K resistor. So, 4.4v/1260Ω=3.49ma.
That's two tubes. You do the rest and just add them up for the total B+ current.
If you're wondering about PT or choke sizes, my PT is a Hammond 269JX rated for 500vCT @ 69ma dc. And the choke is a Hammond 155H rated for 5H @ 50ma dc.
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Thanks sluckey.
Brad :icon_biggrin:
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Here's a LED/LDR version of a vibrato circuit. Might be adaptable to your favorite 12A_7 tube.
http://www.freestompboxes.org/viewtopic.php?f=13&t=4861&hilit=tube+vibrato
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Thanks sluckey, the link was very helpfull. I found a page while reading in there from R.G.Keen on phase shifters and flangers that is very interesting.
Here's a schem I drew up, what do you think? Might be a lot of work for not any or little difference in sound. But a real Leslie does have a hi/low combo. output ---plus--- the sound sources are spinning ---and--- in a cabinet with louver baffels that all add up to a lot of reflections and cancellations and who knows what else is shaping the sound.
The phase shift coupling cap values could be changed to different values in each of the hi/low shift stages. The univibe uses 4 different value phase shift/coupling caps. Maybe use 1 set of values for the low and the univibe set of 4 in the high shifter. That's if I go to a 4 stage shifter.
I'd like to see if the 2 different schems to control/wiggle the cathodes is enough to make a big enough difference to hear. Maybe not. :dontknow:
I still think adding a feedback loop and inserting a 4ms to 20ms? delay, now maybe on just the hi or low signal would thicken things up a bit more. Keen says you just have to be carefull to only use a very small amount or it will oscillate, but done right "you can feed back enough to cause frequency peaks at places where the signals reinforce, and keep the cancellation notches"
Or maybe just string the 2, -3 stage shifters together to get a 6 stage shifter?
I'm gonna play around with this and see what happens. :think1:
Thanks, Brad :icon_biggrin:
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@ Willabe, if you are thinking of selling some of those SRs you got, let me know. TIA Pete
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Yay! 2 SR's arrived in the mail today. Big thanks to Willabe :worthy1:. Now I can finally get on this bandwagon.
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Willabe what is the LDR you are trying out in this new idea?
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tubeswell, just glad they got to you safely. It's a Looooong way from Chgo. to NZ. :laugh:
Keep us updated on your build.
plexi, I'd have to find my notes but I did a search and found some guys who were very happy with the LDR's that they used in uni-vibe clones they had built.
When I find them again I'll post the numbers.
Thanks, Brad :icon_biggrin:
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I am contemplating using one of my SR units (that I got from Willabe) using Steve's unit design, but taking on PRR's comments about the bypass stage and the gain on the driver stage for geetar use (and seeing as how Steve's unit had a spare triode). So I'm looking for some feedback on this schematic please.
1) will the driver stage (with a gain of about 5 - I think?) work okay this way (with the 1M level pot parallel with the 1M bootstrapped grid load for the 1st 12AU7 stage)? Or is it 'better' to put a level pot before the 'driver' stage (as Steve did in his original design)?
2) do the CF bypass stage's values look okay? (just borrowing it from a 6G15 CF bypass). I'm wondering if this will help better with the output impedance of the unit overall? (i.e.: does putting the CF bypass output 'in parallel' with the last 12AU7 stage's output (via the mixing pot) lower the output impedance overall?
3) any other things anyone can see that I might've missed. (should I be starting this in a new topic? seems a shame not to keep this intriguing discussion going)
I also have another variation in mind utilising an additional triode in the LFO driving stage (like the brown harmonic vibrato a.k.a. 6G4/6G5 etc) but I will post that schematic when I've finished doing it.
TIA Cheers
Pete
Edit (realised I did a blooper on the 12AU7 power supply decoupling - corrected version attached - sorry)
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And this one is based on the "Liquidator" (more knobs) but has the CF bypass (instead of the 'recovery' inverting stage).
Qn1: will the feedback control serve as a 'level' control somewhat?
Qn 2: Or would it be 'better' using the spare triode as a recovery stage (as per the Liquidator) i.e.: instead of having the CF bypass?
(Edit: same 12AU7 power supply blooper fixed in this version)
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And this is the above concept with a brown trem:
1) Is this too fanciful/waste of tubes? (i.e.: will the effect of the brown trem be noticeable?)
2) Is the red line the best place to take the trem input from?
3) Any additional comments?
TIA
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The same as above but with switchable brown trem/vibrato effect (either mixable to buffered dry signal)
Is there any issue with leaving the SR connection floating/unconnected to the oscillator when switched into Brown trem mode?
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Look at page 9 of my scrapbook (http://home.comcast.net/~seluckey/amps/misc/Amp_Scrapbook.pdf) for an explanation of that brown trem circuit. (I know it's a slightly different circuit from yours, but the circuit operation is the same.)
You're trying to drive the SRs with the guitar signal, not the trem oscillator signal. The SRs are current devices and will want a lo z driver such as a cathode follower. You could pick up the trem signal at the wiper of the Depth pot, run it thru a CF then apply to the SRs. No need to actually switch off the SR drive. Just switch the guitar output signals.
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TFT Steve. I'll go back to the LFO /CF driving the SR (like in the earlier variants).
Re: the CF bypass, what are your thoughts on that? Waste of space?, or maybe instead have it driving the output of the whole effect?
Pete
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Re: the CF bypass, what are your thoughts on that? Waste of space?, or maybe instead have it driving the output of the whole effect?
I guess that's OK. I like (better) the idea of mixing the wet and dry at the grid of the CF then using the CF to drive the output jack. I don't have a clue what it may sound like, but if you plan for the extra circuit, you can try it either way.
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I like (better) the idea of mixing the wet and dry at the grid of the CF then using the CF to drive the output jack.
Something like this?
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Yes, something like that. You may need another mix resistor in series with the input. Notice that you have a big feedback loop from output straight back to input? Dont know how that may affect the operation.
Why do you want a CF? Will you be using long patch cords and/or an A/B switch between the warbler and amp? The circuit is capable of driving a high z input such as a tube guitar amp input.
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Re: the mix resistor, I was thinking that the 'recovery' stage's signal was sufficiently strong that just turning up the level pot with one mix resistor would be enough to overcome the guitar p'up level signal in going straight into the CF grid. Also I was thinking there would be no reduction of the dry guitar signal (whereas if I'd used a pair of (say) 270k mixing resistors, that forms a 50% voltage divider for the dry signal. The other way is a 250k pot for a mixer control, but the recovery stage's signal may be too strong for that to work well. (or would 1M be sufficient?) (The reason I was thinking a recovery stage may be good on this version with all the pots, is the otherwise-high AC load at the output).
Re; the CF stage, Sometimes I use a 3 metre cable going out to the amp, and there can be a lot of interference in some gig situations. My standalone reverb unit puts out a really nice dry signal in this regard.
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Im glad you all are still working the different ideas and changes. Long live this thread! Occupy Hoffman :worthy1:
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After reading this whole thread, I have to make an effort not to try building something like this ! The brain is getting too old.......
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Got just about all teh parts I need and am making progress on layout design and chassis build. But yesterday whilst staring at the latest schematic, I spotted what I think will be a fatal flaw with the way the 'effected' signal is 'mixed' back with the dry signal, in that having the level pot wiper going more or less straight to the grid of the input stage creates a feedback loop. I might rethink the mixing of it a bit more - shouldn't be a biggie tho'. Either a straight mixing pot at the output, or a common anode mixer arrangement of some sort...
Looking forward to the sounds of getting it going
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Okay, after staring at the previous schematics a bit longer I was wondering about a more direct copy of the 'Liquidator" but with a CF bypass - so that is variant #7 (which uses a dual ganged pot to blend the effected and dry signals without any other feedback going on. The effected signal is recovered by a gain stage because all the 'mixing' knobs would tend to be lossier than Steve's version, so I'm thinking that this would probably be necessary if I pursued this option). I had a spare triode, so it got a paralleled input stage, but you could have more fun with that too I guess.
It could be simpler - but I'm quite keen to hear what the 'liquidator' sounds like.
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CLEAR!!!!!!!
I feel a pulse.
Sorry to revive an old thread but I am about to start building the stand alone vibrato and I have a few questions.
- I know that some have eliminated the fast slow switch from the amp, do must of you prefer it in the fast or the slow position.
- How much plate voltage and current do you really need I know that the original effect was built using a 500VCT transformer at 69mA, but could you use more or less voltage and what is the bare minimum current capacity. Using Ohm's law I calculated that the effect is drawing about 16.5mA of current assuming V4A is less than 1mA.
- Would it be possible to add a LED off terminal #7 on the SR to pulse with the beat of the LFO?
- The last thing I was thinking about changing was to eliminate the foot switch and add true bypass foot switching of the entire device. Do you think I will get residual pulsing in my circuit. I have seen a few pedals that even though they are bypassed they still have residual noise.
Thanks again.
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Finished the unit last night and I am really happy. I am going to add a two (2) button foot switch to switch between fast and slow and add true bypass. I did change the Slow By-pass cap to a .022 and I am happier with that value. I'll post pics shortly.
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I'll post pics shortly.
:thumbsup:
Brad :icon_biggrin:
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Looking forward to the pics. I have another tranny so i may build another unit using whatever upgrades you have come up with
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I've got two more. One is going into a rack mount.
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Finished the unit last night and I am really happy. I am going to add a two (2) button foot switch to switch between fast and slow and add true bypass.
I've found that true by-pass switches don't work well with tube pedals (too hard to eliminate popping when switching). The easiest thing to do is to let the input always go to the 1st tube (this won't weigh down the signal) and switch output between the effect and the source. When you have the switch bypassing the effect, use another switch section of the DPDT (or 3PDT) to send the effect signal to ground through a resistor, so no DC builds up between your CF coupling cap and the switch.
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Crappy Cell Phone Pics
(http://i82.photobucket.com/albums/j250/Jhtjon/Amps%20and%20Stuff/IMG_1658.jpg)
(http://i82.photobucket.com/albums/j250/Jhtjon/Amps%20and%20Stuff/IMG_1657.jpg)
I seem to get significant signal loss with the mix control in the middle position. Is this normal?
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Oops - I was replying to a months old post. Doh!
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That looks very well done! How did you make your faceplate and what did you use?
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I drew the design in Corel Draw and sent the file to BNP lasers. The material is 1/16 reverse engraved black plastic with white fill. it costs about $18-20 per panel.
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I've got another SR unit that Brad sent my way. I'm going to put that one in an amp with vibrato
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I drew the design in Corel Draw and sent the file to BNP lasers. The material is 1/16 reverse engraved black plastic with white fill. it costs about $18-20 per panel.
Thanks Jhtjon.
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I seem to get significant signal loss with the mix control in the middle position. Is this normal?
I think the guys might have missed this question?
Brad :icon_biggrin:
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I drew the design in Corel Draw and sent the file to BNP lasers. The material is 1/16 reverse engraved black plastic with white fill. it costs about $18-20 per panel.
Very nice looking, inside and out! :bravo1:
I'm going to put that one in an amp with vibrato.
Interesting. :thumbsup:
Brad :icon_biggrin:
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I seem to get significant signal loss with the mix control in the middle position. Is this normal?
I think the guys might have missed this question?
Brad :icon_biggrin:
Which schematic?
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I seem to get significant signal loss with the mix control in the middle position. Is this normal?
I lose volume too. Almost sounds like some phase cancellation going on when mixing wet and dry. Does it even with the depth control on zero. But it does give some different sounds when the vibrato is on. I still prefer the mix to be all wet though.
Very nice work BTW. Wish I could make my stuff look that good.
Tubeswell, it looks like revision 1 since there is a mix control, only one filter cap on the board, and only half of V3 is being used.
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Which schematic?
There you go Thtjon, show us please so they can work it out with you.
Brad :icon_biggrin:
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I seem to get significant signal loss with the mix control in the middle position. Is this normal?
I lose volume too. Almost sounds like some phase cancellation going on when mixing wet and dry. Does it even with the depth control on zero. But it does give some different sounds when the vibrato is on. I still prefer the mix to be all wet though.
Very nice work BTW. Wish I could make my stuff look that good.
Tubeswell, it looks like revision 1 since there is a mix control, only one filter cap on the board, and only half of V3 is being used.
Isn't the vol drop just because there is only 1 gain stage on the 'dry' side of the mix control? (Or are you talking about the vol dropping on the 'wet' side?)
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There is plenty of volume at each extreme of the pot and the full wet volume is pretty well matched to the full dry volume. But when the mix pot is somewhere in the middle the combined signal volume is somewhat lower than either extreme. The lower volume is not useless. There are still some good sounds, although I prefer the full wet sound. I may put a scope on it today to see better what's happening.
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Then it probably is NFB as you say.
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I have the same problem with the mix pot some where in the middle. It looses the mix and seems to be cancelling out the signal
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I've been using a Warbler for some time, and, in addition to the favorable comments made about the effect, I'd like to add:
1. It sounds great with the LFO off - really fattens up the sound, so I leave it hooked up even when the chorus is off.
2. The LFO's slowest speed is a little too fast for my taste, so I upped the cap values to slow it down a little.
Bob
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My warbler (I posted this on another thread some time ago but can't remember what its called)
(http://farm9.staticflickr.com/8430/7731733584_0c2ebdae28_b.jpg)
(http://farm9.staticflickr.com/8286/7731723150_26ae66ed2b_b.jpg)
(http://farm8.staticflickr.com/7133/7731726216_8d0bd2c83d_b.jpg)
(http://farm9.staticflickr.com/8282/7731724566_5453cc63b0_b.jpg)
(http://farm9.staticflickr.com/8286/7731727726_5bde97fa3f_b.jpg)
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tubeswell your pics look so good i just want to touch and pull that warbler right out of my computer screen. Great workmanship/
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My warbler ...
I recognize Hoffman's old chassis in that pic! The one with the solid aluminum endblocks...
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The end-blocks on my warbler aren't solid aluminium, they're steel sheetmetal (and everything is welded on - even the flanges). I wire-brushed the outside and then clear-coated it with plastic urethane straight away.
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nice work TW. bravo! how does it sound?
--DL
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http://www.nzguitars.com/forum/download/file.php?id=9003 (http://www.nzguitars.com/forum/download/file.php?id=9003)
http://www.nzguitars.com/forum/download/file.php?id=9002 (http://www.nzguitars.com/forum/download/file.php?id=9002)
Or, for a more subtle vibe:
http://music-electronics-forum.com/attachments/17060d1327830636-fbi-jm-viberater-.mp3 (http://music-electronics-forum.com/attachments/17060d1327830636-fbi-jm-viberater-.mp3)
http://music-electronics-forum.com/attachments/17061d1327830879-flingle-bunt-2-jm-viberater-.mp3 (http://music-electronics-forum.com/attachments/17061d1327830879-flingle-bunt-2-jm-viberater-.mp3)
http://music-electronics-forum.com/attachments/17062d1327830918-man-mystery-jm-viberater-.mp3 (http://music-electronics-forum.com/attachments/17062d1327830918-man-mystery-jm-viberater-.mp3)
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The end-blocks on my warbler aren't solid aluminium, they're steel sheetmetal (and everything is welded on - even the flanges).
I see. Doug used to have a few chassis that looked exactly the same, but were aluminum with aluminum endblocks thick enough to tap for screws.
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nice
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I seem to get significant signal loss with the mix control in the middle position. Is this normal?
I lose volume too. Almost sounds like some phase cancellation going on when mixing wet and dry. Does it even with the depth control on zero. But it does give some different sounds when the vibrato is on. I still prefer the mix to be all wet though.
Very nice work BTW. Wish I could make my stuff look that good.
Tubeswell, it looks like revision 1 since there is a mix control, only one filter cap on the board, and only half of V3 is being used.
Sorry I've been away. Yes it is rev.1
I was wondering if there is also a way to make the depth control a little more responsive. mine doesn't do much below 1/3 on the dial
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Tubeswell -
Really like the tone you are getting in the last 3 MP3s (fully mixed ones). What are you using for the reverb and amplification? thx.
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A PR clone (with a Weber 12A125A) IIRC
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Tubeswell - You should send one of these MP3s to Weber to post on their 12A125A page! Great tone, playing, and recording IMHO. Thanks kindly for the info!
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Hey Pete, I really like those songs!
I can't get the 1'st 2 open but the last 3 were great!
Your playing through that rig is top shelf, IMO.
Brad :bravo1:
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Tubeswell I was thinking about the sounds you are getting from the Warbler on those clips.
Are you using all 3 phase shift sections? You have pots on each section to dial in/dial out the stages output, IIRC.
It sounds more like the pitch shift vibrato Fender used in the brown face amps. I didn't realize the Warbler could do that sound. Sluckeys sound clip does a real nice Leslie type sound.
I guess I'm asking how did you have all the controlls set?
Brad :think1:
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I haven't started taking notes of where the controls are set yet ;-)
I'm still just fiddling with the knobs until I hear something different to what it was before. There's quite a range of sounds.
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I just bought 2 AO-41's and 2 AO-47's ($75 + $20 shipping on ebay, w/o tubes), so I should have more than enough saturable reactors now. I might try six stages to see how that impacts things. The project will have to wait until spring though.
In the meantime, I was wondering if these might be work as off-the-shelf replacements for the reactors:
http://www.mouser.com/ProductDetail/Xicon/42TL013-RC/?qs=sGAEpiMZZMv0IfuNuy2LUU84BnGSKFUnNRUMZXD4nDg%3d (http://www.mouser.com/ProductDetail/Xicon/42TL013-RC/?qs=sGAEpiMZZMv0IfuNuy2LUU84BnGSKFUnNRUMZXD4nDg%3d)
That's a 11:1 winding ratio, and center-tapped so you can feed the oscillator signal into both ends of the winding and ground the center tap. They won't saturate as easily being audio transformers, but maybe increasing the oscillator signal voltage would help?
Something for me to try next spring...
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Very nice, glad you got a hold of them. Nice price too by saving on the shipping, 4 at < $25 each. :icon_biggrin:
Be carefull with them as the wire fly leads from the coils are pretty small and can break fairly easely.
As far as the transformer you mention, I don't think that will work. IIRC, an SR is a different animal. It's core material is different and is used/picked by choice and meant to saturate. I don't think that by just overloading 1 side of an OT that it will act/function the same as an SR.
Brad :think1:
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In a nutshell, the way the whole circuit works (and any vibrato working with a similar principle, like the Magnatone circuit) is to have a variable impedance cause a varying phase-shift, which is controlled by the circuit's oscillator.
In the Magnatone, varistors are paired with capacitors, with the varistor being a voltage-controlled variable impedance. In the Hammond circuit, the saturable reactors are a current-controlled variable impedance, and work against other cirucit impedances to create a varying phase-shift.
So you can't sub normal transformers or chokes for the saturable reactors, because they really are designed and built differently, to accomplish a different task than typical transformers. If you want to side-step using them, you really ought to look at some other control element for your variable impedance (the old varistors are expensive, new varistors may not work the same way, but vactrol optoisolators are used successfully in tremolo and Univibe-like products).
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Is there a modification to drastically slow the oscillator down. I find I can never quite get it slow enough.
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:bump1:
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Is there a modification to drastically slow the oscillator down. I find I can never quite get it slow enough.
Doubling the capacitance of one or more of the (3) caps in the RC plate-to-grid network in the LFO stage will slow it down. (e.g.; tack another .01uF in parallel with one of the .01uFs) Experiment a bit
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cool thanks
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I went online and downloaded the service manual for the Hammond L-100. In it it has the AO-41 and AO-47 schemos + the layout drawings for them and at the very end of the manual a parts list divided into the individual circuits.
Looking at the AO-47 schemo they have a foot note on the LFO drivers tail cathode R133. It say's
"R133 or omitted depending on reactor". The parts list say's;
"Resistor 560 ohm R133....Use with Red Dot Reactors." (What's a red dot reactor? :laugh: )
It would seem they had at least 2 different SRs. I'm looking at my SRs and 1 is a little different.
I have 8 of them that are the same. The laminations look like E/E and are silver in color. The 1 that is different looks like the lams are really 2 U's side by side making an E/E form and are copper/pinkish in color. They are both the same height but the different 1 is 1/16" less in wide and 1/64" less (1 lam?) in depth.
I have bought 3 units off e-bay, 2 AO-47's and 1 AO-41. I don't remember which unit the copper colored 1 came from. The others I bought as NOS replacements.
The copper colored lam SR coils have all their fly leads insulation in red and black. The silver colored SR coils fly leads that go to the tube phase shifter circuit side are red and black. But they have the fly leads that go to the LFO with yellow and green insulation. And the silver colored 1's have a little bit heaver gauge wire.
I'll take some pics and post them in a little bit.
What do you guys have as far as lam color and wire insulation color. And do you know which unit they came from?
Here's the link;
archive.org/details/HammondOrganCo.-L-100ServiceManual
Brad :think1:
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Here's pic of the copper colored lam SR coil. You can see the split in the coil lams running top to bottom.
Brad :icon_biggrin:
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Here's more. You can see the slightly heaver gauge wire and insulation color for the fly leads on these. Note the coil lam color.
Brad :icon_biggrin:
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I'm getting ready to finally build the Warbler.
I brought this idea up early on in the thread about putting in a passive loop for a delay pedal.
I'm thinking that you could send the output back to the input delayed a few milli seconds and it would get phase shifted again. Kinda like the regeneration controll on a flanger?
I think I'm gonna need a couple of R's for a mixer at the grid for V1b? I'm not sure that I need the 2'nd 1M volume pot on the loop return?
Will the 1M send pot be a problem with it being tapped off the 500K output pot?
Do you think it will work as drawn?
Brad :icon_biggrin:
Edit: Fixed send return pots wiring, added mixer R's.
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I'm getting ready to finally build the Warbler.
I brought this idea up early on in the thread about putting in a passive loop for a delay pedal.
I'm thinking that you could send the output back to the input delayed a few milli seconds and it would get phase shifted again. Kinda like the regeneration controll on a flanger?
I think I'm gonna need a couple of R's for a mixer at the grid for V1b? I'm not sure that I need the 2'nd 1M volume pot on the loop return?
Will the 1M send pot be a problem with it being tapped off the 500K output pot?
Do you think it will work as drawn?
Brad :icon_biggrin:
This may be one of those suck it and see moments
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This may be one of those suck it and see moments
:laugh:
I still think I need at least a pair of 220K R's for a mixer like with a 2 channel input.
Brad :icon_biggrin:
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Not sure whether 220k is necessary, but you may want to consider putting a level control (or some sort of level attenuation and/or frequency filter) on the feedback loop. At this stage its a bit of a guess as to whether the feedback is going to be too much for the circuit. Whatever you do about that, I guess the FX loop idea would be better as a parallel loop - in relation to the NFB loop (rather than a serial loop).
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but you may want to consider putting a level control (or some sort of level attenuation and/or frequency filter) on the feedback loop. At this stage its a bit of a guess as to whether the feedback is going to be too much for the circuit. Whatever you do about that, I guess the FX loop idea would be better as a parallel loop - in relation to the NFB loop (rather than a serial loop).
I have a 1M pot on both the send and return jacks for now in the drawing.
What NFB loop? :dontknow:
The loop on the bottom of the drawing is dry signal to mix at the output with the phase shifted signal.
The reverse Fx loop, delay loop is in phase output to input.
Brad :icon_biggrin:
Edit: Fixed send return pots wiring, added mixer R's.
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What NFB loop? :dontknow:
The loop on the bottom of the drawing is dry signal to mix at the output with the phase shifted signal.
I meant feedback loop
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PRR brought up that the last gain stage could probable be lost. I think it was Dave who tried it and posted it worked for him.
Will this work to get rid of the 1 spare triode? To keep the dry signal in phase with the phase shifted output signal at the mix pot I took the dry signal from V1a K bypass caps ground end.
Brad :think1:
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Ok, I'm pulling the trigger on this build. :icon_biggrin:
I feel this is my best layout to date as far as short ground loops and short grid wires. The drawing looks messy because of my trying to show the termination of the twisted pairs being split evenly between their +< > - eyelets/turrets. There's only so much you can do with the Sch program. Drawing is to scale.
I'm really pleased with how the LFO and driver came out, becaues of the LED, at least on paper.
I've got my layout drawing ~95% finished and have almost all the parts I need to build it. I need to double check. I am going to use a pair of Hammond simi-toride PT. 1 for HT B+ the other for 12acv heaters.
Also I'm going to use PCB 5mm x 20mm fuse holders, at least on the secondaries.
With 2 PTs do I need to use 2 fuses for the primaries, 1 for each PT? It would probable be the safest way?
See any mistakes? Please let me know.
Brad :icon_biggrin:
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I've been tinkering with my Warbler this week and have made several changes that I think have really improved the sound and added a little eye candy...
1. Added LED to oscillator circuit for visual only.
2. Moved foot switch to provide instant on/off operation. LFO runs continuously.
3. Replaced all three .47µF caps with .1µF caps.
4. Added tone control.
5. Lowered gain of V1A and also provided an output from V1A cathode to send to MIX control. This corrects a phasing problem between the dry and wet signals. MIX works properly now.
Here's an updated pdf covering the changes. I'll update the website early next week.
http://home.comcast.net/~seluckey/amps/warbler/warbler_rev2.pdf (http://home.comcast.net/~seluckey/amps/warbler/warbler_rev2.pdf)
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Brad, if you are gonna heat the tubes with 12VAC, you need to remove the jumper between pins 4 and 5. Then connect the 12VAC string to 4 and 5. Pin 9 is not used.
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I've been tinkering with my Warbler this week and have made several changes that I think have really improved the sound and added a little eye candy...
1. Added LED to oscillator circuit for visual only.
2. Moved foot switch to provide instant on/off operation. LFO runs continuously.
3. Replaced all three .47µF caps with .1µF caps.
4. Added tone control.
5. Lowered gain of V1A and also provided an output from V1A cathode to send to MIX control. This corrects a phasing problem between the dry and wet signals. MIX works properly now.
Here's an updated pdf covering the changes. I'll update the website early next week.
http://home.comcast.net/~seluckey/amps/warbler/warbler_rev2.pdf (http://home.comcast.net/~seluckey/amps/warbler/warbler_rev2.pdf)
Soundbytes with the changes?
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you're using a FWB for a unipolar power supply; nothing on the B+ secondary of the PT gets grounded unless you're building a bipolar power supply.
the secondaries are strapped proper for series operation, however, if you ground pin 6 as indicated, it'll leak magic smoke.
if you're building to meet UL/CSA/VDE; then you'd fuse each winding or winding group. but you're not, so use one fuse... :icon_biggrin:
--pete
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Brad, if you are gonna heat the tubes with 12VAC, you need to remove the jumper between pins 4 and 5. Then connect the 12VAC string to 4 and 5. Pin 9 is not used.
Yes.
Pulled the layout parts from my library which at this point has only been 6.3vac heaters. Thanks for catching that. I would not have wired them up that way. I'll fix that on the drawing and repost.
Brad :icon_biggrin:
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Ok, fixed the drawings. I forgot I was using a FWB.
Thanks for picking up my mistakes guys.
Brad :icon_biggrin:
Edit; Found a mistake in the LFO/driver layout fixed it, added Sluckeys updates and added fast/slow switch. Will post new updated drawing Sat.
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I highly, highly recommend you make the changes to V1A circuit. It will make the mixer work like it should. It's very simple to do on your layout. Change the plate resistor to 15K. Change the cathode resistor to 10K. Remove the cathode bypass cap. Connect the wire from the .047µF cap on the left side of your MIX pot to V1A cathode rather than the V1A plate. Once you do this, the phase of the dry signal will match the phase of the wet signal and the MIX pot will smoothly blend between all wet and all dry as you would expect. Leaving it wired as I originally did results in mixing out of phase signals and the effect is a thin sound that changes almost like a phaser (but not as pleasant) as you turn the knob from dry to wet. The thin sound is very much like jumping two preamps together when they don't have the same number of gain stages, ie, out of phase. It took a scope and a sig gen to figure out exactly was happening in the warbler.
The added tone stack (stock 5F10, but also very common in other tweed Fenders) is nice but not a must do IMO. The warbler will tend to mellow out your treble tones and the tone stack just helps put some of that back. I like it, but I also have a lot of high freq hearing loss. It's also an easy mod that requires no change in the layout. The added tone pot connects directly to the volume pot.
Moving the footswitch is really a must, especially if you will run the LFO below 4Hz. The oscillator is slow to build up at slower speeds if starting from a dead standstill. It's fine up around 6-7Hz. The new FS interface allows the LFO to run continuously, and simply kills the input to the driver CF. I highly recommend this. Requires no change in layout.
Adding the LED was purely for the geek in me. No performance change. Looks good on the control panel a'winkin' in it's little chrome bezel!
I changed the three .47µF coupling caps in the modulator hoping to brighten the tone a bit. I heard no change with .047µFs or .1µFs. Might make a difference to a keyboard or someone with good ears.
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I highly, highly recommend you make the changes to V1A circuit. It will make the mixer work like it should. It's very simple to do on your layout.
I already changed the dry signal take off point on my layout/schemo drawings last night. :icon_biggrin:
I have been thinking about the phase of the 2 signals at the mix pot. I am toying with the idea of either dropping the last triode stage (to go to only 3 tubes) or adding a 4th phase shift stage to use that spare triode and see if it sounds any better. I'm going to build it as is for the 1'st one then I'll have something to A/B it against.
Any way I was thinking each triode stage flips the phase 180 degrees from grid to plate. So an even number of gain stages stays in phase from input to output and an odd number will be out of phase from in to out. If I drop the output stage or add another phase shift stage then I would have to move the dry signal take off point. Which I posted a drawing taking the dry from the K.
But I think what is going on is that each of the phase shift stages is not being fliped 180 degrees G~A because their split load and are not fliping the phase? Or it get's nullifed? So really there's only 2 gain/triode stages, the input and output in this circuit that flips the phase from G~P?
I think this is right?
Brad :think1:
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I traced it with a scope. Each stage flips the phase 180 degrees (grid to plate) exactly like it's supposed to. That's how I discovered that the dry was out of phase with the wet. Looking back though, all you gotta do is just count the stages.
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I don't understand.
There's 5 stages in to out. Grid and cathode are in phase with each other and are 180 degrees out of phase with the plate. So dry signal is taken from the 1st stage cathode and returned to the 5th stage. Should be out of phase.
I must be missing something.
Brad :dontknow:
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I traced it with a scope. Each stage flips the phase 180 degrees (grid to plate) exactly like it's supposed to. That's how I discovered that the dry was out of phase with the wet. Looking back though, all you gotta do is just count the stages.
So you ran a signal into the input and traced it with the scope? Was the LFO and driver going at the time you traced the signal? I'm wondering if the scope would show a different phase at the plate when the LFO/driver where going than when their turned off? When their turned off isn't the cathode signal blocked by the SR?
Brad :think1:
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Once you do this, the phase of the dry signal will match the phase of the wet signal and the MIX pot will smoothly blend between all wet and all dry as you would expect.
What do the 2 extreme settings, full up on 10 and all the way down on 0 and half way on 5 sound like now? No phase shift effect at 0? Most phase shift at 5 since the wet signal has the dry signal to work against?
Brad :think1:
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What do the 2 extreme settings, full up on 10 and all the way down on 0 and half way on 5 sound like now? No phase shift effect at 0? Most phase shift at 5 since the wet signal has the dry signal to work against?
0 = total dry, no vibrato effect. 10 = full vibrato effect. Since the vibrato signal is larger than the dry signal, the MIX pot does not blend 50/50 when on 5. The 50/50 point occurs much sooner. But what's a number? My knobs don't have numbers. And you're gonna adjust the MIX by ear anyhow.
Your other questions raise some interesting points. I'll put it back on the bench and take another look and get back to you on those.
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Some new test data to contemplate. Refer to http://home.comcast.net/~seluckey/amps/warbler/warbler_rev2.pdf (http://home.comcast.net/~seluckey/amps/warbler/warbler_rev2.pdf)
The overall phase shift (input to output) is about 70-80º. I'm not even gonna talk about phase shifts of individual stages. This phase shift is constant regardless of whether the LFO/driver is on or off. Now with the LFO/driver enabled, increasing the DEPTH begins to slightly modulate the frequency (vibrato or pitch shifting effect) of the 1KHz test signal. Increasing the DEPTH more causes the frequency deviation to increase. The frequency deviation is ever so slight but you can easily see it on the scope. The sound is a varying pitch similar to shaking your finger on a fretted note, or lightly wiggling a whammy lever. Increasing the DEPTH even more begins to introduce amplitude modulation (tremolo effect). The combined vibrato/tremolo gives a sound similar to a Leslie or chorus pedal. Increasing the DEPTH to MAX will continue to increase the AM until the sound becomes choppy (not very pleasing to my ears). And of course, changing the RATE changes the speed of the modulation effects. With rates below 4Hz you get a nice subtle slow pitch changing sound. 6-7Hz is a nice vibrato (chorus-like) sound. Above 8Hz is too fast for me, reminds me of Crimson and Clover on steriods!
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Thanks for going back in Sluckey for more testing and posting more info. :icon_biggrin:
I remember PRR, HBP and KOC talking about phase shift in an amp/circuit before and the math was very complicated to me. IIRC all amps/circuit have some phase shift from input to output that is not perfect. Some to the point that their unstable.
Even without the math, scope/signal generator or just counting the stages the circuit is saying and so are your ears, that it likes the dry taken from the cathode and not the plate to be mixed with the output and that's what counts. I don't need to understand all of what's going on in there to build one. I'm just glad you found it. :laugh:
Later today I'll go back through the thread and PM the guys who built 1 and point them to your updates .
Maybe PRR or HBP will add some more to the phase topic?
Above 8Hz is too fast for me, reminds me of Crimson and Clover on steroids!
Tommy James and the Shondells? Love it! ("My Baby does the Hanky Panky") I'll have to build a 2nd one to run through the PA if I ever get back in a copy band! Hey, even the Kenny Rodgers song from when he was in the First Edition? "I Just Droped in to See What Condition my Condition was in." I love that song!
" Yeah, yeah, oohh yeah, what condition my condition was in." Wonder what he was messing with when he wrote/sang that? :l2:
Thanks, Brad :icon_biggrin:
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Oh almost forgot, I thought you put a 500KL for the mix pot? Latest drawing shows 250KL.
And how much loss do you think the mix pot and 1M to ground voltage divider adds? It does act like a voltage divider to ground? Looks like from input to the last gain stage it's double, 200mV PP to 400mV PP. Which is still very small. But maybe the 1M needs to be reduced in value, so in equals out?
Brad :icon_biggrin:
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Oh almost forgot, I thought you put a 500KL for the mix pot? Latest drawing shows 250KL.
It is 500K. Don't know how 250K snuck in there!
And how much loss do you think the mix pot and 1M to ground voltage divider adds? It does act like a voltage divider to ground? Looks like from input to the last gain stage it's double, 200mV PP to 400mV PP. Which is still very small. But maybe the 1M needs to be reduced in value, so in equals out?
Yes, the mix pot and the 1M do form a voltage divider that depends on the position of the pot and whether you're looking at the wet or dry signal. When the pot is max CCW, the dry sees no voltage divider but the wet sees a 500K/1M voltage divider (wet output knocked down to 67%). Take the mix pot to max cw and now the wet sees no voltage divider but the dry sees a 500K/1M voltage divider (dry output knocked down to 67%. But when you connect to the input of an amp, these voltage divider numbers change. You then must consider the amp's input resistance. It's true that the MIX is not perfect, ie, goes from all wet to all dry. There's always gonna be a portion of both signals at the output. It works exactly like the mixer on the 6G15. And it's good enough to fool your ears.
There are several things you could do to make the overal gain of the warbler equal to unity, but I purposely wanted to have a little boost on tap for the vibrato signal.
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There are several things you could do to make the overall gain of the warbler equal to unity
Like what?
Here's the layout with Sluckeys changes/updates. I left the .22 coupling caps that I had already gone to from the .47 as the Malory 150's .22 and .1 are the same length and won't change my layout.
1. Moved the dry signal take off point to the cathode and changed it's bias, A/K R's.
2. I added the tone control. I made the tone pot 1M like a 5F10/5E3/5G9, for (maybe) a little more treble?
3. Added the fast/slow switch and fixed a ground mistake I had on the LFO/driver. I needed an extra solder lug which is indicated. Was then able to move a couple more components off the board.
4. Got ride of a few redundant eyelets, which along with above let me add 1 more filter cap. So now the input CLC filter is 66uF/choke/66uF. Should be very quite?
If you see any mistakes or problems please let me know.
Thanks, Brad :icon_biggrin:
Edit; The 20uF 160v filter cap on the dc standoff is backwards, I'll fix it and repost.
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Don't drill your board just yet. You're gonna like what I did today. V3 is totally gone. I boosted the gain of V1A a little to provide an overall gain of two (input to output). Dry signal is once again taken from V1A plate and it's amplitude is slightly greater than the wet signal at the MIX pot. 50/50 blend is back at about half rotation of the MIX pot. The unit still has the same sound but is a little quieter without the output amp. I'll post the new schematic tomorrow when I get it cleaned up.
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Don't drill your board just yet. You're gonna like what I did today. V3 is totally gone.
I boosted the gain of V1A a little to provide an overall gain of two (input to output). Dry signal is once again taken from V1A plate and it's amplitude is slightly greater than the wet signal at the MIX pot. 50/50 blend is back at about half rotation of the MIX pot. The unit still has the same sound but is a little quieter without the output amp.
That's great Sluckey.
I haven't made my template yet for the board. I'll wait, no hurry at all.
Took me what? Over a year and a half to get going on this. :laugh:
Brad :icon_biggrin:
Hey do you think 1 of these will sound good through the Warbler? :m2
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Latest changes. I may be done...
http://home.comcast.net/~seluckey/amps/warbler/warbler_021113.pdf (http://home.comcast.net/~seluckey/amps/warbler/warbler_021113.pdf)
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hi guys
thanks ,,,,,,,,for the topic and this layout .
i must be lucking out here .
i buy a christmas gift for myself every year .got it in november
this year it was a hammond organ 112 vibrato.
with 2 12au7 s and a 7247..
the 12au7 s have a tube sheild and 7247 has no sheild .
looks like another project for me ..
Thank you
tom
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Ok, I think I've got it with your latest updates.
The only real constraints I had were lining up the mix pot so the .047 caps would go to pin 1 on V1a and to the output of the phase shifters 3rd stage. The other was the head cabs face plate opening. If it was a another ~1" longer or so on both ends it would've be easer. Fitting in the tone pot was a real pain. :BangHead:
Sluckey I'm soooo glad you did these up dates to the circuit before I built it. Thank you for posting them!
Brad :icon_biggrin:
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I moved the .047 cap of the mix pot x end and onto the eyelet/turret board. Gives me a +/- twisted pair of wires to go from the pot and output jack to the feed from the dry signal .047 cap and filter cap ground.
I think I like it better.
Brad :icon_biggrin:
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Here's the schematic for V.3 and V.3.1.
Brad :icon_biggrin:
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Sluckey, I'm going to start my face/back plate layout/template on Inkscape today, so I can get it made at the laser engraver.
If you think of anything else or see anything wrong in my layout please let me know.
I'm not very good with Inkscape yet so it'll take me a day or 2 maybe.
Brad :icon_biggrin:
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HELP!!!!
I just had a power outage for a second, went off and right back on. I had the Sch. program for the Warbler open and now I can't get it back open.
When I try to open it I get a message that says;
InvalidcaseinReadLayoutEntryFromFile0
When I click OK box it then gives;
Run-time error '7' Out of memory
All my other Sch. files can be opened. Warbler file when I hover over the title says 536K. So does that mean it's still in there?
Brad :sad2:
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Power off the computer. Wait a few seconds and boot up. Cross your fingers and try again.
Get a UPS and/or a memory stick and use them.
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Already did that, no go.
Went in to my documents list and it's there too. Click once on it and it asks if I want to open or save. Click on save it says it already exists do you want to replace it?
If I would have posted the Sch. here would I have been able to get it back from here? Or would it still be gone because it was stored on my computer?
Brad :BangHead:
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Went in to my documents list and it's there too. Click once on it and it asks if I want to open or save. Click on save it says it already exists do you want to replace it?
Copy it to another folder and try opening from the new location.
If I would have posted the Sch. here would I have been able to get it back from here?
yes
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Copy it to another folder and try opening from the new location.
Hey, that worked! Thank You! :happy2:
Now when I open the Sch. program there's 2 Warbler, 1 says copy. Now both will open but the 1st one, when I click on the save button, after 30 seconds or so, message says; Failed to rename."
I have a memory stick I will start to use it from now on.
I have Norton 360 it has back up could I have gone in there and retrived it?
I tried to use a restore point from Windows but that didn't work. Windows has another option in with the restore point, but I tried the copy file 1st, so I don't know if that would have worked too.
Brad :icon_biggrin:
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Here's the Sch. layout and schemo.
Brad :icon_biggrin:
Edit; Sorry guys, I don't know why it downloaded all the pages from my Warbler?
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Ok, Eyelet/turret boards templets printed out.
Time to work on face/back plates with Inkscape after what turned out to only be a distraction this morning, thankfully.
Brad :icon_biggrin:
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Latest changes. I may be done... (I mean it this time :icon_biggrin:)
http://home.comcast.net/~seluckey/amps/warbler/warbler_021313.pdf (http://home.comcast.net/~seluckey/amps/warbler/warbler_021313.pdf)
1. All tubes are now 5751s.
2. Added 180K across Depth pot to compensate for too much LFO signal due to adding LED. Accomplish the same using a 100K pot.
3. Added new voltage readings.
BTW, my LED died on me yesterday. Hope it's just a fluke but I got my eye on the new one.
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Latest changes. I may be done... (I mean it this time :icon_biggrin:)
I'm going to wait to make the eyelet/turret board until I get my face plate made.
I have to remember how I made the face plate for my 5G9 with Inkscape. I have a friend at church that's a graphic artist that I'm talking with about this. I think he can help me. I sent him a copy of the Inkscape 5G9 FP that the engraver used and a copy of the Sch Warbler FP. I'll see what he has to say.
BTW, my LED died on me yesterday. Hope it's just a fluke but I got my eye on the new one.
Too much current?
I've been wondering how much voltage/current the SR can take. The foot note you have in your drawing on the driver tail R being omitted is referenced in the Hammond manual I posted the link too. It says there was a red dot SR and that's why they have 2 different driver tail R set ups.
You said early on;
I think it's just a normal progression of the circuit. Maybe it was a cost cutting idea (one less tube) or maybe the 12DW7 was not even around at the time the AO-41 circuit was designed. I've played it with both drivers and didn't notice any difference in sound. The driver is not in the signal path.
PRR said they might have had 2 different SR's and made the change when they dropped the 6C4 in the AO-41. But on that model the SR string was biased up to the 6C4 plate voltage.
The '41 circuit is sloppy. The large oscillator swing is cut way down, buffered for no reason, then amplified-up again. The plate swing is probably very much like the oscillator swing. Seeing that, the '47 redesign just put the signal to a cathode-follower, saved a bunch of parts.
The back-story may be more complicated. There may be a saturable reactor re-design before the '41 or between '41 and '47, the older SI needed the bigger drive. An improved SI allowed less drive but the tube-works didn't change right away.
Why all 5751's?
Brad :icon_biggrin:
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Too much current?
No way. B+ is 330V, plate resistor is 470K. Even if the tube was a dead short, you could only pull .7mA thru the plate resistor (or LED). Don't know if reverse voltage was exceeded. I'll check that tomorrow. I'd like to believe that either the RadioShack LED just died of natural causes or I inadvertantly shorted something to the LED during my mad gator clip venture. I can't really say but I'm keeping a close watch on the new LED. And I don't have any problems going back to the original cathode RC if the new LED poops.
Why all 5751's?
Short answer... I got a butt load of 'em!
Yesterday I wasted 4 hours chasing a microphonic chassis and also what sounded like a bad ground hum. Naturally I suspected all the tinkering work I've been doing the past few days. Well, the problem was really a GE 6189 (12AU7). The Sylvanias I had worked better. But by the time I realized that, I had rotated several of those tubes in and out of V1 and V2 positions. The symptoms kept changing slightly.
This morning (fresh start) I decided to try the 5751s in V1 and V2 positions. Immediate cure! Old 6189s back in and symptoms returned. I vaguely remember years ago having to go thru several of those GE 6189s in the radar system to get one that worked well. Anyhow, that problem is cured. Later I decided to try a 5751 in the LFO circuit. Works very well there too. So, for simplicity, I decided to use all 5751s. All 12AX7s would probably work too but I have more 5751s than 12AX7s.
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No way. B+ is 330V, plate resistor is 470K. Even if the tube was a dead short, you could only pull .7mA thru the plate resistor (or LED). Don't know if reverse voltage was exceeded.
And I don't have any problems going back to the original cathode RC if the new LED poops.
What would the reverse voltage be? Do all LED's have a different reverse voltage raiting?
I hope it was RS junk. I realy like the idea of a free speed/rate indicator on the front panel. It also helped my layout.
Is your Warbler any brighter sounding with all 5751's now?
Brad :icon_biggrin:
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What would the reverse voltage be? Do all LED's have a different reverse voltage raiting?
Many 5mm LEDs have a 5 volt reverse rating. Can't say if they are all the same.
Is your Warbler any brighter sounding with all 5751's now?
I didn't notice any change in brightness. But then I was focused on flushing the gremlins!
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thanks ,,,,,,,,for the topic and this layout.
It's Sluckeys baby. :icon_biggrin:
Tom your coming in at a good time with Sluckey refining it a little more.
Brad :icon_biggrin:
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Well, I'm done tinkering with my warbler. All I initially wanted to do was put a blinking LED on it. Ended up with a major revision. I've put some new pics and schematic/layout on my website. Hopefully I documented all the changes! :grin:
http://home.comcast.net/~seluckey/amps/warbler/warbler.htm (http://home.comcast.net/~seluckey/amps/warbler/warbler.htm)
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And some new sound bytes please.
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The sound is basically the same. I'm working on an idea to get some quality sound bytes. I'll post when/if it happens.
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thanks ,,,,,,,,for the topic and this layout.
It's Sluckeys baby. :icon_biggrin:
Tom your coming in at a good time with Sluckey refining it a little more.
Brad :icon_biggrin:
hi Brad
i am so lucky ..
i have been checking out the hammond vibrato L 112
looks like the board is close to steves circuit board ..but hammond style ,,,,,, only needs a change the parts . and pots .But the strange board eyelets look like problems,or messy look after ..
not sure what to do .may be just add it to my amp.,,,,,,,,,,,,,,,.money :laugh: :laugh: :dontknow..:so back burner for the moment
i .need to finish one of three more amps . :think1:
tom
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Hi Tom,
i have been checking out the hammond vibrato L 112
looks like the board is close to steves circuit board ..but hammond style ,,,,,, only needs a change the parts . and pots .But the strange board eyelets look like problems,or messy look after ..
That's where Sluckey got this build from. The part that makes the thing work is the saturable reactor coils. Hammonds L series organs have the SR vibrato. I have 3 of the vibrato units, 2 AO-47 and 1 A0-41. They have solder cups instead of eyelets on their boards. They work.
He has posted all the schematic, layout/wiring and eyelet board template drawings for us all.
Our host Doug now offers a custom turret/eyelet board service at a very fair price and great quality for those who don't have the tools to make their own. Look in his online store for more info on it. It's a very good option for a custom build IMO.
Brad :icon_biggrin:
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If I added an output jack to the dry signal, after it's coupling cap and and disconnected it from the mix pot to send it to a 2nd amp would that be stereo?
I could wire the jacks switch contact so when you plug into the dry output it would disconect the coupling cap from the mix pot.
I think you could use the 2 amps volumes to act as the mix control?
Brad :think1:
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Stereo? Ha! In the sense of all the stomp boxes out there that have ONE input and TWO outputs and claim stereo, absolutely. Just use an AB/Y switch.
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Yes I know it would not be true stereo. But it would spread out the sonic effect in the room by having the wet/dry signals spaced apart on stage, wouldn't it?
Brad :think1:
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Yes I know it would not be true stereo. But it would spread out the sonic effect in the room ...
As much as any other "stereo" effect.
It will probably sound great to you on stage. The audience will likely just hear a mono sound, because after some critical distance (based on the spread of the wet/dry signals and size/shape of the room) the stereo image will blur into mono.
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As much as any other "stereo" effect.
It will probably sound great to you on stage. The audience will likely just hear a mono sound, because after some critical distance (based on the spread of the wet/dry signals and size/shape of the room) the stereo image will blur into mono.
Good point.
Thanks, Brad :icon_biggrin:
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hi steve
i followed the schematic .
not sure but the your board .,,,,,,,,,i am working on the hammond board in the unit..
one thing about v4 ..power C goes to pin 1 no resistor
power B goes to pin 6 with a resistor
the power resistor moves over beside the cap .22uf on your board and connects to it from pin 6.
i think
tom
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Tom,
I don't know when you came into Slucky's thread, but it might be helpful to go back and start at the beginning.
http://home.comcast.net/~seluckey/amps/warbler/warbler.htm (http://home.comcast.net/~seluckey/amps/warbler/warbler.htm)
Brad :icon_biggrin:
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i am working on the hammond board in the unit..
Ooh, I don't envy you! :grin:
Back when I first started with this project, I was using an AO-41 unit for experimenting. I ripped out the original fixed frequency LFO circuit and replaced it with a Fender 6G12 LFO. It was a real PITA to modify that cone board! As soon as I could see this idea was promising, I abandoned the original unit and made my own board.
one thing about v4 ..power C goes to pin 1 no resistor
Right. V4A is a driver/cathode follower. No plate resistor is needed.
power B goes to pin 6 with a resistor
Right. The plate resistor for V4B is a 470K/1/2W
the power resistor moves over beside the cap .22uf on your board and connects to it from pin 6.
I don't understand. There is no .22µF cap in the Warbler. That 56K/2W power resistor on the board is the node C dropping resistor. It's in the lower right corner of the schematic.
The schematic and layout are in agreement unless I've made a drawing error during my recent revisions. If I was ever gonna do another Warbler, I'd use the revision 2 schematic/layout, but I'd eliminate the wasted space on the board, shortening it approx. 3". I'd also take the two node dropping resistors off the board and mount them directly on the cap cans. The only reason they are on the board (originally there were 4 node resistors and two more filter caps) is because I didn't know what values they would end up being. It was much easier to substitute resistors on the board that on the cap cans.
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hi Steve
well it was late and i was watching tv and the computer at the same time .so i was not using my reading glasses ..
it s.022 cap not .22
you will notice on the warbler 2 on your ,,,board ......that there is no power to your pin 6 ,,
but you have the two power lines going to pin 1 on that board .
then the board needs to change ,,,,,,
or as you said,, do not put power resistor for V4 pin 6 on the board and ,, place it at the cap cans ....
i understand about putting the power resistors at the cap cans..then wires can go directly to the tube pins ..i believe
its just so great that you have done all the work for us , thankyou very much.
tom
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that there is no power to your pin 6
Look again after a cup of coffee. :grin:
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ok coffees drank
i see it ,,now .
i was an artist ,, oil painter , flowers . my eyes are not so good now ,
burnt out eyes .so painting is very hard to do for me .plus the boards .
thanks
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Just to be sure I'll shine a light on it...
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i see the light ~
its going great on this hammond L 112 board .vibrato.
i will put in old caps,and rewire to get the circuit right. on this board
I'll have to wait for money for the project .
so i ll wait .,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
then change all the parts to new
i get every thing else done ,,,,,so thats all that i need to do change the old suff . and the tubes will be hidden inside the enclosure.,,,,,,,,,, with epoxy on them to hide their true make and plate type. :dontknow:... :l2:
also i have no tubes .
i only have a dozen or abouts,, 12ax7 s and hand fulls of 12au7 s.... afew 12at7 ,12bh7,
thanks for the light . now more coffee.. :think1:
tom
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I happened to run across a guy recently who was able to get a copy of Hammonds spec sheets for the SR unit.
Their going to give me a bid on making them, it'll be a few weeks. He's also not sure if they have the right mechines to wind them on because there so small.
Brad :think1:
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All right I have my schemo and layout drawings finished. I also have my face/back plates layout drawings ready to take to my friends house. I'm going to try and go see him Sat. and have him draw them out (and my GA-77 plates) with a vector program so I can send them to the engraver.
Then I can drill out my chassis using them as the template so they'll both line up with each other.
Sluckey, I've been thinking that it might be better to insert the input volume and tone controls between the mix pots wiper and output jack. I like the idea of running the input stage preamp at full for signal to noise ratio reasons and driving the phase shifter stages with the full signal.
The way I have the layout no pots or jacks need to be moved, just flip/flop the volume/tone pots and rewire. The output signal will be right next to the input jack, but it was going to be there before. I had the mix pot with the dry signal coming in right next to the output jack. I could rotate the tone pot 90% CW to get a little more distance from the input jack.
Do you think I can wire them up this way?
I think I'm going to temp in a 50K pot for the wet/dry ballance, set it where it sounds right and then measure it's resistance and put in the closest R value.
Brad :think1:
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Your idea to put the tone control at the output is probably better than having it at the input. I still like having a volume control before the modulator, although putting it directly on the input jack like I did seems to just be an extension of the volume control on the guitar.
The tone control is very worthwhile regardless of where you put it. I had considered the simple control of the 6G15 reverb unit, but it was very easy to tack on the 5E3 style to the volume control. Once I did that and saw how effective it was, I just never tried the 6G15 tone control.
I think I'm going to temp in a 50K pot for the wet/dry ballance, set it where it sounds right and then measure it's resistance and put in the closest R value.
That's what I was going to do too. You'll need to replace the pot with two resistors. The only 50K pots I had were the 2 watt PEC locking pots. It was actually easier (and looks better) to install the pot permanently than it would have been to put two plate resistors on the board. If I did not already have a board it would be simple to plan the layout for two plate resistors, and if I was where you are right now, that's what I'd do. I certainly would not buy a PEC pot just for the balance function. It's really a 'set it and forget it' function. And I'm not totally convinced that the dry and wet signals really 'need' to be the same level at the mix pot, it's just a 'why not' kind of thing.
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I still like having a volume control before the modulator,
Ok, why?
To be able to increase or decrease the drive to the 3 phase shifter stages for a different texture/effect?
If I go with the round barrel knobs from a Fender brown face instead of chicken head knobs I can add that control.
Which 1? A, B, or?
Brad :icon_biggrin:
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Ok, why?
To be able to increase or decrease the drive
yes
I don't like A because the pot is backwards. But A and B both have dc on the pot. If I were gonna put a pot there I'd do it like this...
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Just had an idea, don't know why I didn't think of it before. :blob8:
I was thinking of putting in a feed back loop and inserting a delay into it to re-modulate the output signal by running it back in at the 1st phase shift stage but slightly delayed to thicken/layer the effect.
But, if I put in a loop and insert a delay pedal to delay only the wet/modulated signal then the dry mix signal should work against the wet signal like a flanger.
Then if I can add the feed back loop it will act like the regeneration control on a flanger. Might even be able to use 2 delay pedals, 1 in each loop with different settings?
Brad :think1:
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I don't like A because the pot is backwards.
That was to keep the tubes gain constant and just limit the drive signal. :dontknow:
But A and B both have dc on the pot.
Oh, yes, I see now. Because it's bootstraped. :BangHead:
If I were gonna put a pot there I'd do it like this...
Ok, C it is. I can get that in pretty easy.
Thanks Sluckey, Brad :icon_biggrin:
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Well I think this will work, what do you think?
The pots (CTS) will only be 3/16" apart, a little tight but should be ok?
I have tried to lay this build out as best as I know how and spent a lot of time doing so. I think it will fly. But....
Any more suggestions, additions or corrections please post them. I'm set to go see my friend next SAT. to get my face/back plates drawn up in a vector format to send to the engraver.
I'm going to leave the loops out of this build. All I have to do is disconnect the x and wiper on the drive/volume pot to pop in the wet signal loop to experiment and see what it does.
The 2nd (feed back) loop I'll try after the 1st and see what it does.
Had another thought. A flanger splits the input signal and delays 1 side of the split at the same time modulating it, a little faster, a little slower according to how you set the controls. Then it mixes the wet/modulated delayed signal with the dry.
So if I insert a delay pedal into the loop it's just a set delay. But if I inset just the wet signal from a flanger pedal now it injects a delayed and modulated (faster/slower) signal to the input of the phase shifter. Then at the mixer the pitch shift will be delayed from the dry signal. So called stereo flangers and delays have separate wet/dry outputs so it can be tried. (A chourse pedal is another modulated time delay pedal I could try.)
Might even be able to get some kind of doppler effect by having the wet signal delayed and changing the speed of the LFO with a foot pedal?
I really have no idea what any of these will sound like, they may just sound like mud or they might not even work, but OTOH, they could sound very good. :dontknow:
I think their all worth a try.
Thanks, Brad :icon_biggrin:
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The pots (CTS) will only be 3/16" apart, a little tight but should be ok?
I don't know what that means unless you mean the body of one pot is 3/16" separated from the body of the adjacent pot? I put my pots on 1.25" centers. Some chicken heads will work, others won't. Dakaware barely touch when nose to nose. If I had to have chicken heads, I'd put them on 1.5" centers because I hate to have to move one pointer just to turn another knob. Those black aluminum knobs on my warbler are 3/4" diameter and work very well. Pricey though.
I'm beginning to think you just need to build a proto (mockup) rig like Buttery has. Then you can easily try out all these other ideas you have. However, if you stop thinking about all the extra stuff you 'can' do and just build it as is, you won't be disappointed.
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I don't know what that means unless you mean the body of one pot is 3/16" separated from the body of the adjacent pot?
Yes. Too close?
I have a mojo 18w head cab here and the front opening cut out is 13.5", my chassis is 17.5". I could order a new head cab and have them widen the cut out. That's a standard up grade they offer.
I put my pots on 1.25" centers. Some chicken heads will work, others won't. Dakaware barely touch when nose to nose. If I had to have chicken heads, I'd put them on 1.5" centers because I hate to have to move one pointer just to turn another knob.
What's Dakaware?
The chicken head knobs I have are 1.25". The Fender barrel brown/cream knobs I have are 13/16". I need another 1/8" past the knob diamiter for the face plate hash marks. So chicken heads need at least 1.25" + 1/4" + another 1/8" (= 1 5/8") space inbetween them so the hash marks don't touch. The barrel knobs I have need 13/16" + 1/4" + 1/8" = 1 1/8". I set up the 4 control pots in my layout at 1 3/16" on center. (I used 1 5/8" on center pot spacing, their CTS pots, on my 5G9 with chicken head knobs, which looks good to me.)
I have the snap to grid set up for 1/16" x 1/16" and it lets you go inbetween the dot's , so 1/32" x 1/32" grid. It woks very well for my layouts so far.
I'm beginning to think you just need to build a proto (mockup) rig like Buttery has. Then you can easily try out all these other ideas you have.
Yes, I do and not just for this build. It's becoming clear to me that it will come in very handy to experiment with.
However, if you stop thinking about all the extra stuff you 'can' do and just build it as is, you won't be disappointed.
Agree, I'm going to leave the loops out and build it as is. Final drawings are posted below. PSU B+ nodes and grounds are indicated.
Thank you Sluckey, Brad :icon_biggrin:
Edit; Fixed tone control drawing wiring.
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I don't think your tone control will do what you expect. Try this...
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Thanks.
I was trying to find a neater way to draw it out (not yours, my drawing) and got it twisted up. I believe the layout drawing is correct.
I fixed it and reposted above with edit note.
What's Dakaware?
Brad :icon_biggrin:
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What's Dakaware?
Dakaware is a brand name. Their chicken heads look classier IMO. More expensive though.
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Oh, ok.
Got better looking lines/shape to it. + raised back/top. I like them.
Thanks, Brad
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I believe Doug used to carry those. If you look at his old Revibe, you'll see them, but if you look at his recent rack mounted revibe (or his current inventory) you'll see the 'flat top' chicken heads. It's a subtile difference and if you never see them side by side, you probably won't know. I definitely like the looks of the Dakaware much better, but at double the price, I'll buy the flat tops. :grin:
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IIRC, AES sells them. But there's the hitch in the giddy up, as always. $$
Brad :laugh:
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Those are not Dakaware but they sure do look better than the flat tops. And not bad for $1.40. Wish I'd seen them 2 weeks ago.
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I was just over at Mojo and they also have a raised top/back chicken head knob in several colors, but a little more $$ than AES.
Brad :icon_biggrin:
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I'm going over to my buddies house tomorrow to get the vector art work done for the Warbler and the GA-77. Hopefully I'll be able to have the engraver make them early this week and so I can drill out my chassis. :icon_biggrin:
Sluckey, I've been thinking about how the wave form you posted was slightly different top from bottom. That could be a good thing as far as the sound of the effect. Now it's said a univibes wave form is off a little too because of the light bulb in the cathode leg of the circuit because the filament heats up and cools down at slightly different speeds. It's thought that it helps add color to it's sound by changing the shape/sound of the "wobble" of the effect.
Since there seems to be a slight time constant being introduced in the univibes circuit, I was wondering if this could be done in the Warbler?
Now there's AC and DC at the LFO's drivers K. But could a light bulb be put in between the cathode of the LFO driver feeding the SR? Or maybe in series with the K tail R? Or maybe a large C in series with a large value pot to ground to form a variable time constant to skew the wave form? All though I think with a C/R it would charge up and down at the same speed?
If something could be done to skew the balance of the wave form it would be nice to have at least a little bit of user adjustment on it.
A small amount of adjustment would probably be enough to hear a change in the effects sound.
Brad :think1:
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You're thinking waaaay too much. Put those idle hands to work. :wink:
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I need my face plates so I can drill my chassis! :laugh:
My buddy had to play at a wedding last weekend and I got pushed back a week.
But really can a pilot light type bulb be put in the LFO K?
Brad :think1:
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Now it's said a univibes wave form is off a little too because of the light bulb in the cathode leg of the circuit because the filament heats up and cools down at slightly different speeds.
What are you talking about? Transistors don't have cathodes.
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What are you talking about? Transistors don't have cathodes.
Yes, I used the wrong term. I should have said emitter. But you know what I ment and I posted the Univibe schemo. Made me dig out a book to look it up. :laugh:
Brad :icon_biggrin:
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Still don't get it. There are no light bulbs connected to any emitters.
That univibe is the ss equivalent of the warbler! Functionally the same, except the univibe has one more modulator stages.
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Yes 4 stage SS phase shift. Same type of set up.
4 LDR's, (instead of 3 SRs) 1 for each stage to control the phase shift of it's own stage. All 4 LDR's driven by 1 light bulb that's driven by the LFO.
Because of the heating/cooling of the filament, the turn on/off of the bulbs filament, cycles at 2 different rates causing the LDR's to shift the phase a little unevenly making the phase shift wave form uneven. If it's that 1 half of the 360% phase shift cycle, ie, on or off, is on a little longer or 1 half's amplitudes attack, sustain and decay wave form is different than the other or it's some of both, I don't know.
Like an oval shaped wheel turning or like the guys who intentionally throw the output of a PI out of balance for different/thicker sound.
(I think your yanking my chain for fun but I have too much respect for you to bark back.)
Brad :laugh:
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all 4 LDR's driven by 1 light bulb that's driven by the LFO.
Yep, but that bulb is connected to the collector of Q13, not an emitter.
(I think your yankin my chain for fun...)
That's right! I'm just jousting with you since you won't get off the pot and drill some holes. There are a lot more holes to drill than just that face plate. There are probably 100 or so holes just on the board! I'm ready to see some results of all your work! :grin:
But mainly, I'm just avoiding answering that question. :icon_biggrin:
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Yep, but that bulb is connected to the collector of Q13, not an emitter.
Your still dogin me, you know I'm talking about Q3, Q5, Q7 and Q9.
There are a lot more holes to drill than just that face plate. There are probably 100 or so holes just on the board!
That's the easiest part of the whole build. :laugh:
Cut the board on table saw with diamond blade, sand edges, tape paper template to board, drill on bench top drill press, set eyelets with eyelet staking anvil in bench top drill press table, done, 1/2 hour, 45 minutes at most.
Drilling/cutting the chassis and trim plates is what worries me.
But mainly, I'm just avoiding answering that question. :icon_biggrin:
It's a valid question. :think1:
Brad :icon_biggrin:
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Your still dogin me, you know I'm talking about Q3, Q5, Q7 and Q9.
Well now I'm beginning to see. But the part of that highly proprietary optocoupler that connects to those transistors is not a light bulb. Those four elements are CdS (cadmium sulfide) photo cells or photo resistors. The single light bulb inside that optocoupler that really connects to Q13 collector just shines on the four photo resistors to change their resistance at the LFO rate.
Drilling/cutting the chassis and trim plates is what worries me.
That's fun too. Don't fret. What's a trim plate?
It's a valid question.
Are you sure? :wink:
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Still don't get it. There are no light bulbs connected to any emitters.
That univibe is the ss equivalent of the warbler! Functionally the same, except the univibe has one more modulator stages.
The univibe also phase shifts different frequencies in each stage, see the different capacitors used (15nf, 220nf, 470pf, 4.7nf). I recall reading somewhere this was to simulate the Leslie rotating cabinets.
With the warbler it's all the same frequency, you get 2 phase shifts which are 180 degrees, and will produce a notch and thus a phaser sound if mixed with the original right there. And then you also add another 90 degree shift, with the third stage, but still the same frequency so that's 270 degrees.
I'm thinking of going 6 stages to get a nice deep phaser, and then some fancy relays to switch behaviors to univibe-style vibrato and some other variations on the theme (pseudo-chorus maybe).
Anyhow hope I got all this theory right, still haven't built anything with those reactors I bought a few months back...
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Well now I'm beginning to see. But the part of that highly proprietary optocoupler that connects to those transistors is not a light bulb. Those four elements are CdS (cadmium sulfide) photo cells or photo resistors.
Ahh, my fault, wrong name again. I'll try to remember that.
The single light bulb inside that optocoupler that really connects to Q13 collector just shines on the four photo resistors to change their resistance at the LFO rate.
Yes, so since the photo resistors are driven by the single light source, all 4 are effected by how evenly or not that bulbs filament turns on and off. It's said it changes the "wobble" of the modulator.
This is supposed to be part of the Univibes mojo.
IMO, it would be well worth trying to figure out how to change/adjust the "wobble" of the modulators in the Warbler. Can a light bulb be placed in series between the LFOs K and the SR string?
That's fun too. Don't fret. What's a trim plate?
Yeah it is great fun when I get it right. I'm a carpenter, I don't have much experience working with metals, but I'm getting better.
Got to break a few eggs to make a cake. Face plate, ~$20, chassis, ~$50. :w2:
I know your just trying to keep me grounded in common sense Sluckey, thank you.
Are you sure? :wink:
Guess it depends which side of the modulator wave your on? :m2
Brad :laugh:
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The univibe also phase shifts different frequencies in each stage, see the different capacitors used (15nf, 220nf, 470pf, 4.7nf). I recall reading somewhere this was to simulate the Leslie rotating cabinets.
With the warbler it's all the same frequency, you get 2 phase shifts which are 180 degrees, and will produce a notch and thus a phaser sound if mixed with the original right there. And then you also add another 90 degree shift, with the third stage, but still the same frequency so that's 270 degrees.
Yes! That's supposed to be the 2nd part of the Univibes mojo. Thanks for posting that point.
I didn't want to add that in to the conversation till I could post the first part right where the guys would understand what I was trying to say.
shoggoth , have you listened to the sound clips that Sluckey and Tubeswell have posted playing through their Warblers? They sound better than the Univibes that I've played through.
To me, anything that could be added and is either switchable and/or adjustable would only be a positive at this point.
I'm going to build it as is, which is IMO already a wonderful sounding effect and play with it from there.
Brad :icon_biggrin:
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Willabe, I really don't know the answer to your question, so I just decided to mess with you a bit. It was all in fun. Too much free time these days! :grin:
I've been thinking about how the wave form you posted was slightly different top from bottom.
That's something I've noticed about all the phase shift LFOs I've looked at. None have been a perfect sinewave, but pretty close. I don't have a clue as to how the non symmetry might affect the sound. I suspect that the slight difference in positive and negative half waves would make very little difference in this case.
Here's an idea I have kicked around some. The original liquidator circuit (got the warbler idea from the liquidator) did not have an onboard LFO. Instead, he used a programmable function generator capable of complex modulation waveforms. I was gonna use my HP 3310B function generator to experiment with sine, square, and triangle/ramp waveforms. But my prototype warbler showed so much promise with the simple Fender LFO that I put the idea on hold and just never got back to it. My HP does not have adjustable dutycycle so I could not experiment with non symetrical waves anyhow. I may play with that yet.
But honestly, I'm so pleased with the warbler at this point that I really don't want to change anything else. You're gonna like it too. Now git 'er done. I want to still be alive to enjoy it with you! :laugh:
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Willabe, I really don't know the answer to your question, so I just decided to mess with you a bit. It was all in fun. Too much free time these days! :grin:
I know, your good in my book. :icon_biggrin:
Now git 'er done. I want to still be alive to enjoy it with you! :laugh:
Ok, ok. :laugh:
Going to my buddies house at 4:00PM tomorrow, that will break the damn.
Thanks, Brad :m2
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shoggoth , have you listened to the sound clips that Sluckey and Tubeswell have posted playing through their Warblers? They sound better than the Univibes that I've played through.
I just did (again), and yeah it sounds a lot nicer than the Univibe.
So the warbler puts it through three 90 degree phase shifts, you end up with a 270 degree shift. Theoretically this would be roughly the same tone as a single stage with just a 90 degree shift.
Now I expect that in fact the saturable cores all have audibly different reactances, because I don't think the tones I hear in those clips are the same as you'd hear from just doing a single stage 90 degree shift. So that's providing three shifted frequencies. But that's all just a guess, only mixing in the first stage to the dry signal and seeing how it sounded would provide the proof of the matter I suppose. The variance in capacitance values will also impact the frequencies generated.
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What's a trim plate?
Face/back plate. Could call it a dress plate.
Brad :icon_biggrin:
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Well I just got back from my friends house. :happy1:
He did the art work in a vector program for the face/back plates for both the Warbler and GA-77.
Man is he good at what he does! It was a real pleasure to see someone with his experience and talent work in the vector program on a computer.
Next, call the engraver and e-mail him the files.
Brad :icon_biggrin:
Edit; Looks bad because I cropped it in Windows 7 paint.
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Sluckey, turns out DAKA-WARE (Davies Molding) is still in business.
Look in here;
http://www.el34world.com/Forum/index.php?topic=15348.0 (http://www.el34world.com/Forum/index.php?topic=15348.0)
Brad :icon_biggrin:
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An aside - I'm working on taking a Zenith battery operated radio and changing into a guitar amp, using the tubes it came with as a design constraint.
I just listened to Sluckey's clips again, and they sound remarkably like the problem I'm trying to get rid of w/ the heptode tube (it's modulating the clean signal with some noise on the directly-heated cathode). Maybe I should call it a "feature".
Of course it's fixed frequency in my heptode (presumably 120hz), as opposed to a varying frequency, and so can quickly become an obnoxious ring modulator sound depending on the intensity.
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How do you have 120Hz in a battery operated amp?
An aside - I'm working on taking a Zenith battery operated radio and changing into a guitar amp, using the tubes it came with as a design constraint.
Do you also have the battery (batteries) it came with? If not, using the battery tubes may be a problem. I don't know cause I have no experience with them.
But it does remind me of the 25v or so battery required by the battery box of the first piezo guitar pickup (the Prismatone, as in Jerry Reed's Baldwin classical and the first Ovation guitars), which users swear by. If you don't have the old battery, you're S.O.L. So in that case, some guys rig up a small solid-state power supply to replace the battery.
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How do you have 120Hz in a battery operated amp? Do you also have the battery (batteries) it came with? If not, using the battery tubes may be a problem. I don't know cause I have no experience with them.
No, I don't have the battery - the supply I built has a few issues I'm debugging, and thus the 120hz sneaking in where I don't want it.
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Went over and met the new engraver. She sure seems to know what she's doing as an engraver. I then e-mailed her the vector program face/back plate drawings. She was very happy with them because they were done in a vector rather than with a bit-map program.
Also went over to Johnsons Plastics, talked with them, got a full line catalog and ordered some color samples. Got them in 2 days and they look real good to me. I think I'm going to go with the reverse engraving stock to protect the color film and what ever gets engraved. The down side is you have to paint fill the engraving. :dontknow:
I'm waiting on different colored knobs from AES, should be here Mon. or Tues. but I think I'm going with a black base with white lettering and markings. They do have a very dark blue, green and brown. They almost look like their black but would pick up and tie in with a blue, green or brown shade of tolex. White or cream colored knobs with light colored markings/lettering should provide easy to see controls on a dark stage.
I should have the plates in my hands by late next week.
Gonna warm up here next week into the high 30's/low 40's. So I can cut my eyelet/turret boards outside without freezing and get going on them while I wait for the dress plates.
Brad :icon_biggrin:
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Is this the best way to add a bypass chassis switch?
Or is it best to also lift the input/out put jacks ground feed wires to the jacks because of noisy ground current?
If this is right, then I need to add Doug's relay boards which I have on hand.
Brad :think1:
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> you have to paint fill the engraving
Use wax crayons.
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Use wax crayons.
Hmmm..... :think1: Thanks PRR sounds that's a good idea. But.....
The Warbler chassis won't get hot enough to melt the wax, but what about on a combo amp with say a pair of 6L6's and a rectifier tube?
Brad :icon_biggrin:
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Did you finalize the schematic? Cant wait to see your results ,pics. Think when i get time i have to build another using the updated schematic. I have one more transformer.
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Did you finalize the schematic?
Yes. I'm hoping to drill/punch out the chassis this week.
Brad :icon_biggrin:
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You can mix your own crayon with a hard wax, some white pigment (maybe even a crayon), and a dash of turpentine (check that against the plastic). Hardens as the turp comes off.
Seriously: this was often used in the old days. You scrape it in like spackling a wall-crack, scrub it off the flat.
Remember that softening wax on the stove can start a serious fire.
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Ok, I'll try it.
Thanks.
Brad :icon_biggrin:
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davies molding chicken-head knob with the comb is part #2300 - pg. 33 in the 2013 catalog.
allied has them -->click me!<-- (http://www.alliedelec.com/Search/ProductDetail.aspx?SKU=70097829&mkwid=sACn3o2ox&pcrid=31466108016&pkw=2300bt%20davies%20molding&pmt=b) and the price seems decent...
--pete
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Thanks Pete.
I called them today and they said minimum order is only 100 pieces and color match is a small added fee. The women took my info and said she'll get back to me with a quote.
I'd like to get a deep/dark blue chicken head knob. They do make a blue but I think it's to light in color. She said she'll send a sample.
I'm trying to match up the colors of tolex I like with the face/back trim plate material, knobs, handle, piping and grill cloth color. :BangHead:
I did find the leather handle with "footman loop" hardware I like in 6 colors on line at http://www.goodcomponent.com/index.html (http://www.goodcomponent.com/index.html)
Sure looks like what mojo sells and Mesa uses.
I'd also like a nice dark brown and they still make that color. In fact they have a couple of browns they make.
I asked her if they still said Daka-Ware on the knobs underside. She said she thinks that they repaired the old molds and left that out when they did.
I called back the engraver today and told her the color of the face/back trim plate. She has to find out if the suppler has it in stock and will get back to me in a day or so with a price. If it's reasonable I'll give her the go ahead.
Brad :icon_biggrin:
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davies molding chicken-head knob ...
allied has them ...
So does AES (http://www.tubesandmore.com/products/P-K302), though it doesn't appear they tell you they're from Davies. I used the rose-colored ones (http://www.tubesandmore.com/products/P-K302RO) for my Standel.
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Well I talked with the engraver today and she said I can pick up my face/back plates tomorrow around noon. She apologized for taking so long. Said they had family in from out of town for Easter. :dontknow:
I also have cut my eyelet boards and have the templates taped on. They look good to me, will drill them out tonight and swage in the eyelets and turrets.
Brad :icon_biggrin:
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I'd like to get a deep/dark blue chicken head knob. They do make a blue but I think it's to light in color. She said she'll send a sample.
on stage a dark blue will appear to be black? medium blue?
i even like the chicken if the sauce is not too blue... :icon_biggrin:
--pete
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Brad, would you re-post your final schematic/layout? THX...
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OK, here they are including the blue chicken head secret sauce.
(I might not need the 2 shielded wire runs.)
Brad :laugh:
Edit; PT eyelet board heater PT is wrong, should be a 229A 24v (6VA) at 500mA when wired for 12v. It's a little smaller than the 229B which is 12VA. I will post the corrected board later.
Edit; Fixed LFO pot labels as pointed out, thank you Pete.
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brad, you have the rate and depth pot labels reverses.
respectfully...
--pete
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brad, you have the rate and depth pot labels reverses.
Thank you Pete, but you just scared the heck out of me. :laugh:
That would have messed up my face plate because I'd have to re-do my layout. :BangHead:
Thankfully it's only on the LFO schemo. The layout drawing is correct and that's the drawing I used for the face plate.
I'll fix that and repost.
Brad :icon_biggrin:
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Well I picked up my face plates for both the Warbler and GA-77 and I'm very happy with them. :icon_biggrin:
The hash marks are a little long, going inward to the center on the Warbler, but the knobs will cover them.
I'll find my camera, take a picture and post with a knob or 2 sitting on them.
Brad :icon_biggrin:
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OK, here's a couple of photos of the face/back plates.
Sorry about the glare from the sun through the window but I think you can get the idea of what they look like?
The back plates have the protective clear film removed to see the color a little better.
The 2 knobs on the left on the GA-77 are cream, 3rd is white. Knobs on Warbler plate are also cream color and a dark blue mini chicken head from AES. I need to get a few dark brown CHs from Weber speaker to see if I like them better than the cream. (I know you can't see the colors very well, will do better next time.)
I like the font style but my friend might have made the letters a little too thick, but he can thin them back to their original thickness for future builds. He thought it would make the words easer to read on stage.
Notice the small pilot center holes for the tip of the brad point bit. I need a 1/8" pilot hole through the plate and chassis for the step bit.
Their reverse engraved and she used the smallest cutter she had for the pilot holes. The tip of the brad point when seated all the way down into the hole seems snug with no slop or play side ways/left/right. It should be self centered.
Brad :icon_biggrin:
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on stage a dark blue will appear to be black? medium blue?
Yes, tis true.
I'm kinda thinking more about what the amp will look like in the light of day or in the house under normal living room lighting.
Brad :dontknow:
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Drilled out the chassis and face/back plates today. Still need to drill out for the eyelet/turret boards and choke.
Here's some pictures, sorry I need to work on getting the glare out. You can't even see the eyelet/turret boards.
Brad :icon_biggrin:
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Lookin' good!
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I finished punching and drilling the chassis. I still need to drill a couple holes for the safety and chassis circuit grounds, plus any holes for a solder lug terminal, maybe 2 or 3.
I scratched up the back side of the chassis a bit. Can I sand it out with 220 grit on an orbital sander? It's an aluminum chassis.
Sluckey you polished your's, looks beautiful, how'd you do that? Fine grade grit sand paper on an orbital sander and then hit it with a car orbital buffer with some buffing compond?
Here's some pictures.
Brad :think1:
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Sluckey you polished your's, looks beautiful, how'd you do that? Fine grade grit sand paper on an orbital sander and then hit it with a car orbital buffer with some buffing compond?
That's basically what I did. But I was more low tech. I used 330, 400, and 600 wet/dry silicon carbide paper with water lubrication. Hand sanded in a straight line until scratches were gone then progressed to a finer grit. Then I used some military metal polishing compound applied by hand. Then buffed the compound off with a buffing wheel in my hand drill motor.
Your method will probably work better. Don't know that I'd start with 220 grit though, unless the scratches are really deep.
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Don't know that I'd start with 220 grit though, unless the scratches are really deep.
The scratches are not very deep. I'm not used to working with metal so in my mind 220 grit for wood is pretty fine. Wet sanding makes for a better result because of the slurry effect when sanding. I can do that. I have a 5" orbital sander but I don't have an orbital car buffer. It's going inside a cabinet so it doesn't have to be polished to a mirror finish, but I'd like to not see any difference, more or less, then the rest of the chassis. I just want to even it out again.
Thanks for the info Sluckey.
Brad :icon_biggrin:
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Man that looks beautiful! Your really got the passion going on. I need a jump start
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Thanks Plexi.
It's looking good but it still has to fly.
James Taylor, "sweet dreams and flying machines in pieces on the ground".
Brad :icon_biggrin:
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Any progress?
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Some, sanded the chassis. Looks fine now.
My wife's sick with the flu, taking care of her.
Maybe I can get some wiring done today?
Brad :icon_biggrin:
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Ok, major progress today.
I wired up the PSU, IEC with self contained fuse, 2 PTs, 2 power switches, safety ground, B+ snubber and dc stand off.
Bent the leads on the radial B+ caps so they fit into the turrets.
Stuffing the main circuit board right now.
Brad :icon_biggrin:
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Fun isn't it?
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Yes!
Main board now has the 3 stage shifter parts stuffed, still need to add the fly leads from the board to the tube sockets.
LFO and CF driver is next.
Brad :icon_biggrin:
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All right, a little more progress. I got the LFO/CF driver on the eyelet/turret board stuffed and laced up the B+ filter caps turrets in parallel for the CLC .
I forgot to say in the last progress report that I tested both PT's for B+acv and they where fine.
More tomorrow hopefully, my wife has been very ill with a stomach/intestinal virus for 4 days now. I think she's finally past it now.
Brad :w2:
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Since my color scheme on this build is a blue face/trim plate with a blue jewel pilot light, I'd like to go with a blue K LED for the vibe indicator.
I found 2 at RS with nice a chrome bezel, just like Doug sells, but a just a little bit bigger in diameter.
Question, will they work? Here's the spec's,
1. > 5mm, 5v, 30mA, 300mcd, 24 deg. viewing angle.
2. > 5mm, 3.7v, 20mA, 2600mcd, high intensity, 30 deg. viewing angle.
See any problems using either of these?
Brad :icon_biggrin:
Edit; added LED viewing angle.
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I experimented with about 10 different color and voltage LEDs. They all seem to work, but the higher voltage LEDs would drop out at slower and faster speeds. IOW, they operated over a narrower LFO frequency range in that particular circuit. Too narrow for my liking. They may be fine in another circuit though, or you may be able to tweak the warbler circuit to work better.
Reds, yellows, and orange (the under 2 volt LEDs) work very well with no fuss. Radio Shack has an assortment pack of LEDs that contains some yellow that look more like an incandescent bulb. The LED casing is clear with no diffuser. That's what is in my warbler. I have an orange diffused LED in my revibe. It really looks more like gold color to me.
EDIT... I recommend using red initially. Then when everything is working fine, start experimenting with different colors.
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Ok. I'll pick up a red LED at RS today that will fit the bezel I got from them.
Thanks, Brad :icon_biggrin:
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Got some more done, here's some pictures.
Forgot to say I fired up the 2 PTs, separately with a variac and monitored the voltage with a meter. All was fine.
The brown, orange and green on the underside of the eyelet/turret board are the K connection for the SR coils. I left them long and kept the grid connections short and twisted with the K wires. Hammond had these wires running next to each other but didn't bother to twist them. The red and black bias coil wires were run away from these wires, I'll do the same. I'm using the same colors for the SR wires because I have the same colors they used. This way it will be easy to wire it up with Hammonds drawings.
These wires, except for the short K wire run will be run down against the chassis and away from any eyelets/turrets in the circuit board. B+ wires are down against the chassis also. I'm using 3/8" stand offs.
The 2 power switches are only tempt in. I only had SPST on hand and want to use DPST to kill both primary (+/-) wires for safety.
I hope to get the board, tube sockets and SR coil wired up today and maybe some of the controls.
Brad :icon_biggrin:
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I don't have a 500K for the mix pot on hand. I can use a 1M with a 1MR across the o/x ends of the pot until I get 1, right?
I got a couple of red LED's from RS that fit the bezel I bought there. I have 4 red LED's I bought from Doug, but their 3mm (15/64" chassis hole) and I drilled out the chassis for the RS 5mm (5/16" chassis hole) bezels.
1.8v, 20mA, 120mcd, 40 deg. viewing angle.
1.7v, 20mA, 3000mcd, 12 deg. viewing angle.
Brad :think1:
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Killer Brad. Man this is looking great. :worthy1:
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Thanks Ed.
If I keep at it, maybe I'll get it done by June? :laugh:
Brad :icon_biggrin:
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I don't have a 500K for the mix pot on hand. I can use a 1M with a 1MR across the o/x ends of the pot until I get 1, right?
You can use that 1M without a resistor. And probably forever. I chose 500K for no particular reason other than because I had one. :wink:
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Got a question about the phase of the SR coils.
Looking at the Hammond AO-47 chassis I have and the Hammond drawings some things not right.
Red and black wires are flip/flopped from start to finish on opposite sides end to end, pins 1/7. Hammond schematic drawing doesn't have the SR coil wire colors, but their layout drawing does show the SR coils wired pairs colors. If you look at the schemo, SR 103 coil goes to the 3rd stage with C106 plate coupling cap and it's bias coils are fed from the LFO drivers K.
In the Hammond chassis I have, SR103 is the 3rd stage coil and is the blue/green pair. But on the SRA coils the black ground wire, pin 7 is across from the blue/green pair, pins 8/9, not the red LFO driver bias feed.
And you have pin 1 going to ground with pin 7 feeding the bias coils with pins 13/12 going to stage 1.
Or doesn't it matter which end of the bias coils you bias up or ground, as long as you don't flip the phase coil wires?
It's easer to see it in the drawing below than to write it.
Brad :think1:
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You can use that 1M without a resistor. And probably forever. I chose 500K for no particular reason other than because I had one. :wink:
OK, sounds good to me, thanks.
Brad :icon_biggrin:
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Or doesn't it matter which end of the bias coils you bias up or ground, as long as you don't flip the phase coil wires?
Quick answer, it does not matter.
Remember, I used an AO-41 chassis, not an AO-47 chassis for my warbler. In the 41, the SR was plate driven, ie, one end of the primaries was connected to the plate of a tube and the other end was connected to B+. In the 47, The SR was cathode driven, ie, one end of the primaries was connected to the cathode and the other end was connected to ground. There's a phase reversal right there.
My 41 SR assembly had no markings on it whatsoever. I arbitrarily assigned those numbers to the SR terminals so I could connect it exactly the same as it was connected on the original. The main focus was on the secondary windings. I filed a notch in the top right corner of my SR while it was still mounted in the AO-41 chassis and called the top/right terminal pin 1, just like a 14 pin DIP chip. Then I counted clockwise until I ended up at pin 14. That seemed logical to me. There are many other ways the terminals could have been labeled, but using a familiar DIP chip pin assignment was easier for me.
Bottom line, keep the secondary wiring exactly as shown. And primaries, pin 1 and 7 can be swapped at will and you'll never be able to tell the difference.
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Quick answer, it does not matter.
Bottom line, keep the secondary wiring exactly as shown. And primaries, pin 1 and 7 can be swapped at will and you'll never be able to tell the difference.
Ok then. Will do. Putting in the board and SRA now. I do have my SRA numbered the same as yours, as in my drawing. I agree it makes sense the way you numbered it.
Thank you, Brad :icon_biggrin:
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Ok, good news and a little bad news.
I have every thing wired up except for the front panel controls, the components that hang from them, LED and the eyelet/turret board tag leads. Tubes heaters light up. Tested for 12.6vac on the tubes, I'm getting 13.4vac with a ~125vac wall voltage. A little high but within 10% +, 12.6 + 1.26 = 13.86. B+ no-load is ~350 vdc at 1st filter cap node.
Went to put the pots in and the CTS pots I have the bushing is too short to get the nut on. :BangHead: :cussing:
My chassis is .090" (~3/32"), face plate is 1/16", so very close to 5/32".
CTS with plastic shaft > bushing = 1/4", shaft = 3/8", marked > CTS 3MEG 0831 on sliver colored back cover shield. (I'm pretty sure I bought it from Doug.)
ROC with metal shaft > bushing = 5/16", shaft = 3/8", marked > 0990926 1M A 9804 ROC on gold colored back cover shield.
PEC with metal shaft > bushing = 3/8" , shaft = 1/2", both of those measurements are from the center of the brass colored ring/washer in between the bushing and shaft.
ROC pots bushing is just long enough with the star washer in place to tighten down the nut with the top end of the bushing just barely coming out a .001" or so.
PEC pots shaft length will cause the knobs to be sitting up off the face plate, it will look funny to me. AES's spec sheet says the PEC 2w pot's shaft is 3/8". How'd I get a 1/2" shaft? :BangHead: :cussing:
Any body know where to get the ROC pots? And do they make a 3MRA? AES and mojo don't have them.
I could cut the shaft on the PEC pots with a dreamel but that's a pain.
I'm going to go ahead and wire up what I have and swap out different pots later.
Brad :icon_biggrin:
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I could cut the shaft on the PEC pots with a dreamel but that's a pain.
Not as painful as where you are right now. I would not hesitate to cut them. But I'd use a hacksaw and a bench vise. Stick the end of the shaft in the vise and use the edge of the vise as a guide for your hacksaw. For example, say you want to cut odd 1/8". Then stick 1/8" of the shaft into the vise. Then just use the side of the vise jaws as a guide for the saw. Some of the PEC shafts are hard so use a new 32 TPI blade and go slow. Should take about a minute. Finish off with a little touchup filing and you should have a nice square cut.
I don't really have an answer to the pot that the bushing is not long enough for the faceplate. I used Doug's CTS pot for my speed pot and the bushing on it is just long enough to pass thru my .09" chassis and allow the nut to fully engage. There ain't no extra bushing length! I couldn't even use a star washer, but the thin flat washers that come with the Alpha pots will securely lock the pot in place.
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Good idea about the vice. I have a couple here that should work nicely.
Some of the PEC shafts are hard so use a new 32 TPI blade and go slow.
I think their stainless steel?
Thanks, Brad :icon_biggrin:
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Good idea about the vice. I have a couple here that should work nicely.
Some of the PEC shafts are hard so use a new 32 TPI blade and go slow.
I think their stainless steel?
Thanks, Brad :icon_biggrin:
yes, they're stainless steel... i use a dremel but have a wet washcloth handy to soak away heat. you don't want the shaft to get too hot when cutting with the dremel. otherwise slucky's hacksaw method won't heat things up too bad.
--pete
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Thanks DL, I seemed to remember they were stainless steel.
I just remembered what I did before on the 5G9 I built. It has the same LFO and driver and I used the 3MRA CTS pot I bought from Doug.
I used the thin star lock washer from the PEC pot and although the bushing doesn't clear the outside top face of pot nut it does grab the bushing threads about 1/2 to 2/3rds of them. I wouldn't fell comfortable selling or fixing an amp like this but for myself I can live with it.
Back to work.
Brad :icon_biggrin:
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Check with Steve at apexjr.com
He has a lot of NOS pots. His website does not have everything listed so you may need to call him. I have had the same problem of the threads not reaching and or the shaft being too long. Old radios present this problem often. The reverse pot is probably your worst concern.
I use PEC mostly except for the RA pot. Your knobs may have enough plastic in the inside to drill them a little deeper. The cool thing about CTS pots is you can take them apart and replace the thread with a longer one. A fastener company can supply hollow threaded rod. If you can get the rod, you could use CTS all the way. If not just simply get solid and get a local Machine Shop to put it into a lathe with a bit in the tailstock and drill your own. Take the warbler with you as they will be fascinated with it and much more inclined to do it as a favor. The only other option I can think of is to mount the pots without the faceplate. Drill the faceplate larger to go over the nuts and attach the faceplate in a different way. This is provided you have knobs with a large enough base to cover the nuts, which they should.
This is the problem you run into restoring old radios all the time and at one time or another I have done everything I have mentioned.
Not to worry, the solution will come.
T
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Thanks DL, I seemed to remember they were stainless steel.
I just remembered what I did before on the 5G9 I built. It has the same LFO and driver and I used the 3MRA CTS pot I bought from Doug.
I used the thin star lock washer from the PEC pot and although the bushing doesn't clear the outside top face of pot nut it does grab the bushing threads about 1/2 to 2/3rds of them. I wouldn't fell comfortable selling or fixing an amp like this but for myself I can live with it.
Back to work.
Brad :icon_biggrin:
mojotone sells custom mfg. CTS pots with the .4" long bushing including the 3MRA trem pot. they're the pots that you need for fender amps that have the brass backing plate and you wish to use the star-tooth washer. cost is steep - about 3.60 for most values, and the 3MRA is 5 bux. they used to sell these pots with a nylon shafts like the original 60's fender units had, but now all that they carry are made with a brass shaft.
http://www.mojotone.com/amp-parts/potentiometers-CTS (http://www.mojotone.com/amp-parts/potentiometers-CTS)
all other CTS and alpha brand pots i've bought from CE/AES have the standard .375" long 3/8-32 bushing unless you're buying a "genuine fender" replacement part.
--pete
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Thanks Ed and DL.
It was a little heart breaking at first after I had measured and re-measured everything for my layout drawing only to have forgotten the pot bushings. :BangHead: :laugh:
I'm going to order some from mojo or AES soon, but I'll finish wiring it up with what I have on hand.
Brad :icon_biggrin:
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All right, I've got the tube sockets wired up and am working on the LFO parts that go on the panel controls.
On an LED the flat spot (and is the shorter leg) on the housing lens is the cathode, right? And the cathode goes to ground in this circuit, right?
I think I'll get it finished today. I have to finish the LFO controls then all that's left are the input/output jacks, bypass switch, 4 pots, the drive, tone, volume and mix.
Brad :icon_biggrin:
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LFO is wired up. Fired it up, LED comes on and is blinking. Turning the speed pot slows down and speeds up the LED. Flip the speed switch and turn the speed pot, slows down and speeds up.
There is a noticeable difference of range in the LED blinking, from fast to slow, when I flip the speed switch and rotate the speed pot.
Tested with a 12AX7 in, seems to be working fine. :blob8:
Now for the input/output jacks, bypass switch, 4 pots, the drive, tone, volume and mix. Should be down hill from here.
Brad :icon_biggrin:
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It's working. :icon_biggrin: Everything is wired up except the panel bypass switch, it was getting late and I was getting tired, will add that in later.
I played it for a little while with a couple of 12AU7's in the 1st >2 positions, 12AX7 in the 3rd for LFO and driver. I need to put the knobs on so I can see where my settings are. I left the drive and volume full up while I played and quickly found I needed to turn the tone control up full. I was playing a rosewood fret board strat on the neck pup, volume/tone both full up, through my (stock) 5E3 clone on ~3, ~4, no verb.
It seems to be, the little I played through it, 15 minutes or so, that moving the mix and depth even a little really changed the effects sound a lot. I don't think the circuit is overly sensitive or finicky, that it's wired wrong or any of my parts are bad, I think it's just a powerful effect with a wide range available between the depth and mix. It's not like a boost/distortion or delay where you add more or less with a single knobs setting, in their most basic forms anyway. It's more involved with this effect and it's settings.
I didn't like it at 1st, but after a few minutes of playing with the knobs I found a few settings I really liked. My wife liked the sound of it right away and her ear is pretty good. :icon_biggrin:
It can go really deep into a chorus type swirl with the depth set past 6/7 and the mix set (I think, I had the chassis upside down with no knobs on) past 5 going towards more dry signal. Gonna take some time to fool with the settings to learn what it can do.
The tone control might be in the wrong place in the signal chain? Steve, you might have had the ticket when you put it on the input. It's only cutting the high end where it's at right now and with the effects thickening of the sound, I can't think of a reason why it would be needed, at least the way it's wired and functioning right now. Maybe if I played the lead pup or with a tele or other bright guitar, but I live on the neck pup for lead and the middle pup (neck/bridge with a pair of bucks) for rhythm.
I need to check all the voltages and the current through the 1R that I put in series with the B+ FWB's ground. I'll post those when I get them. (I did check the voltages as I wired up different sections, B+ but unloaded, heaters and the dc standoff voltage and all were fine.)
My EH Wiggler which is a SS/tube pedal that has 4 basic mode settings on a 4 position rotary switch, plus a vibrato/trim switch. There labeled, Looz, Hamm, Acey and Wurl. It responds the same as the warbler as far as the settings. Just a little bit of change can send you off to a sound that's not really very usable, to me any way. But the sounds that are usable sound really good to me.
Brad :icon_biggrin:
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I do have 2 problems.
1. With the 12AX7 in the LFO/driver socket, turn up the intensity and it thumps, not ticks, but thumps real good. :w2: :laugh:
Here's the specs for the red LED I put in, 1.7v, 20mA, 3000mcd, 12 deg. viewing angle.
I'll try a 12AU7 and see if it helps.
2. The pilot light is acting up. Might just be the bulb. Turns on/off by the smallest touch to chassis when turning the knobs. Unscrew the jewel lens a turn or 2 and it lights back up. I did hit the bulbs base with some fine steel wool, but no go. It's a Fender clone pilot light, never used, a few years old.
I'll post pics in a day or 2.
Brad :think1:
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... seems to be, the little I played through it, 15 minutes or so, that moving the mix and depth even a little really changed the effects sound a lot.... it's just a powerful effect with a wide range available between the depth and mix... It can go really deep into a chorus type swirl with the depth set past 6/7 and the mix set (I think, I had the chassis upside down with no knobs on) past 5 going towards more dry signal. Gonna take some time to fool with the settings to learn what it can do.
Pretty much sums it up for me too. Its a lot more versatile than a straight trem. Have you got some sound-clips to post/link?
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Have you got some sound-clips to post/link?
No, not yet. I just finished wiring it up tonight. I'll try to post something in the next few days.
What do you think about the thumping?
Brad :think1:
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Thumping is because the LFO signal is so BIGGGGG, especially since the LED mod. Mine does it also if you turn the Depth up too much. You can increase that 2.2M to about 4.7M to knock the LFO signal down, or just don't turn the Depth up so much.
I find that I usually set the Mix to max. For slow speeds I like the Depth turned up a lot and for faster speeds I usually turn the Depth down some.
EDIT... More info. I had tried a 5751 and 12AX7 in the LFO circuit and they both seemed to work fine. But later I switched back to the 12DW7. I remember preferring the 12DW7 but I can't remember why. :w2:
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Thumping is because the LFO signal is so BIGGGGG, especially since the LED mod. Mine does it also if you turn the Depth up too much. You can increase that 2.2M to about 4.7M to knock the LFO signal down, or just don't turn the Depth up so much.
I find that I usually set the Mix to max. For slow speeds I like the Depth turned up a lot and for faster speeds I usually turn the Depth down some.
OK, I'll try what you say and see how it goes for me. I still need to dig another 12AU7 and a 12DW7 outa my stock pile and try those.
Thanks, Brad :icon_biggrin:
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I took some voltage readings, here's what I got;
Wall voltage was holding around ~121.7 or so while testing. 12AU7 in V1/2 and 12AX7 in V3.
B+ > 325.5vdc 1st node, 323vdc 2nd node.
264vdc K driver for LFO V3/pin 1 = 264vdc. 147vdc V2/pin 6, 145.3vdc V2/pin 1, 146.4vdc V1/pin 6, 251.5vdc V1/pin 1. V1A is biased with 47K plate R, 10K cathode R.
The 3 phase shift triodes are on the same B+ node, has a 10K dropping R. Input preamp is on it's own B+ node with a 10K dropping R. Do you think I should change values for either?
Now I messed up on the heater transformer. :BangHead: It's a Hammond 229A12 semi torrid/low profile, 115vac primary, when wired for 12.6vac secondary it's rated @ 450mA. I thought the No. 47 pilot light bulbs were 40mA, turns out their 150mA.
I don't know if they pull only 1/2 the current when feed twice the voltage? But....
With the bulb in 11.16vac on heaters, with the bulb out, 12.85vac.DC standoff dcv was 66.8dcv. Wall acv was around 121.7 at time of readings.
Going to put the knobs on so I can turn them easily and see the settings to get my bearings while I give it another try. Also going to put a 12AU7 and 12DW7 in for V3.
Brad :icon_biggrin:
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I don't know if they pull only 1/2 the current when feed twice the voltage? But....
No. If you run a 6 volt bulb at 12 volts it will burn much brighter and draw twice the current. A #1849 runs at 12v and will fit that bayonet socket.
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No. If you run a 6 volt bulb at 12 volts it will burn much brighter and draw twice the current. A #1849 runs at 12v and will fit that bayonet socket.
Oops. :laugh: So 3x12_ _ 7@12.6vac=450mA + 1x6.3, 150mA bulb run@12.6= 300mA= 750mA from a PT rated for 450mA. I'll get a few of those bulbs.
Thanks, Brad :icon_biggrin:
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Tried a 12AU7, 12AY7 and 12AT7 in V3. None of them thumped even with the intensity set to full. But these 3 all would stop oscillating if I turned the intensity and or speed down to far, like ~3 or less. Then it was a little hard to get it going again. 12AT7 worked the best but still stopped. I have a few 5751's laying around in a box, need to find them and give them a try. If they don't work I'll try upping the 2.2M and see if that will get the balance of not thumping but not turning off the LFO.
Also the lower gain tubes let the LFO go slower than the 12AX7. I thought at 1st with the 12AX7 in I was going to have to change out 1 of the .01 LFO caps for a .02, now until I find a tube that works in V3 I'll have to wait and see.
The other thing is it seems to be over driving the 5E3 clone with its volume only on 3 when the Warblers drive and volume are full up. Turn them down to get the amp to stop over driving and it sounds very thin and sterile. Some things not quite right with that.
Maybe I'll try by passing the volume and tone at the output with a alligator jumper and see if that helps? I wonder if it's an impedance load thing?
I'll also try inserting an A/B box between the guitar and Warbler to the amp and see if that gives me a better idea in my ears of how much it's driving/changing the tone of the amp.
Brad :think1:
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Hummm.... :think1:
Thinking about this more, I think it might be best if I disconnect and not just by pass the 1M drive pot and the 2@1M output volume and tone pots.
Strip it down to the bare bones circuit to eliminate any impedance/load issues?
Brad :icon_biggrin:
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I forgot to add that across the 1 ohm R in the tail of the FWB ground I'm getting a reading of 17mA on dcv setting. And the on/off jack is working.
Brad :icon_biggrin:
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I don't seem to be able to find any 1849 lamps. I may have remembered that number wrong. Here are some current production bulbs that would be suitable. I like the 756 best because of cost, long life, and low current.
I can't comment on the 'thin' sound other than to say that on my first version there were some positions on the mix pot that would produce a thin, almost nasal tone. I chalked it up as a phasing issue. There were still some good full bodied sounds, but the mix never behaved as I imagined it should. That issue was totally resolved in the revised circuit.
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Thanks Steve, that bulb at only 80mA looks good. Long life and price are good too, I'll buy 10.
Brad :icon_biggrin:
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Are you looking for 12V pilot lamps?
If just to say "ON", an LED (with resistor) will last forever.
If power is unlimited, car lamps work. However the common stoplamp (try 1156) takes a large fraction of an Amp, is large, and more of a work-light than an indicator. There's teeny 1W lamps in my 2002 Honda for Cruise indicator and clock backlight, but the socket is way-odd and the life has been short (may be time to re-rig the clock with a white LED?).
A 6V can be run with a resistor on 12V. This will also increase life (reduced cold surge). For the once-common #47, 6.3V 0.15A, use 40 (39) ohms 2 Watt in series.
Two 6V lamps in series is 12V at the same current. (Lower reliability cuz when either breaks, both go dark.)
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Are you looking for 12V pilot lamps?
Yes.
Chassis is already drilled with face plate for a Fender clone pilot light. PT is Hammond 229A12 semi torrid/low profile, 115vac primary, when wired for 12.6vac secondary it's rated @ 450mA. I thought the No. 47 pilot light bulbs were 40mA, turns out their 150mA.
The 756 bulb Sluckey suggested looks like will work. It's only 80mA so, 3x12_ _7, 12vac@150mA= 450mA+80mA= 530mA, looks like my best option so far.
No. If you run a 6 volt bulb at 12 volts it will burn much brighter and draw twice the current. A #1849 runs at 12v and will fit that bayonet socket.
Oops. :laugh: So 3x12_ _ 7@12.6vac=450mA + 1x6.3, 150mA bulb run@12.6= 300mA= 750mA from a PT rated for 450mA. I'll get a few of those bulbs.
With the (#47) bulb in 11.16vac on heaters, with the bulb out, 12.85vac.DC standoff dcv was 66.8dcv. Wall acv was around 121.7 at time of readings.
Thanks, Brad :icon_biggrin:
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Any progress?
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Tried a 12AU7, 12AY7 and 12AT7 in V3. None of them thumped even with the intensity set to full. But these 3 all would stop oscillating if I turned the intensity and or speed down to far, like ~3 or less. Then it was a little hard to get it going again. 12AT7 worked the best but still stopped. I have a few 5751's laying around in a box, need to find them and give them a try. If they don't work I'll try upping the 2.2M and see if that will get the balance of not thumping but not turning off the LFO.
Also the lower gain tubes let the LFO go slower than the 12AX7. I thought at 1st with the 12AX7 in I was going to have to change out 1 of the .01 LFO caps for a .02, now until I find a tube that works in V3 I'll have to wait and see.
The other thing is it seems to be over driving the 5E3 clone with its volume only on 3 when the Warblers drive and volume are full up. Turn them down to get the amp to stop over driving and it sounds very thin and sterile. Some things not quite right with that.
Maybe I'll try by passing the volume and tone at the output with a alligator jumper and see if that helps? I wonder if it's an impedance load thing?
I'll also try inserting an A/B box between the guitar and Warbler to the amp and see if that gives me a better idea in my ears of how much it's driving/changing the tone of the amp.
Brad :think1:
A 12DW7 (or JJECC832) will be the best bet for that trem circuit I think. The LFO stage (V3a) is set up with a 470k plate load that is high - even for a 12AX7, but a 12AX7 can manage that. (This could account for the other tubes' intensity cutting out sooner). Whereas the CF stage has a load of 11k, so that works best with a 12AU7.
However if it thumps with a 12AX7 triode in V3a, then you could try lowering the gain of that stage a bit by using either 390k, 330k, 270k or 220k plate load, and changing the bias point of the stage accordingly to maybe 3k3 or 2k7 or 2k2. You'd have to suck it and see.
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No progress, my wife's parents are coming into town for her sons HS graduation. Working on cleaning up the house and doing yard work. She deserves it and I do like her parents. They live in up state NY, so she doesn't get to see much.
Thanks Pete for the options to try to tame the thump, I'll try them when I get back to it.
Brad :icon_biggrin:
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> Chassis is already drilled with face plate for a Fender clone pilot light
I've put LEDs behind jewel-lamps. LED and resistor, little shrink-tube, hung on the solder-lugs and shining into the jewel. Looks a bit odd behind, but works forever.
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Ahh, thanks, that's a good option.
Brad :icon_biggrin:
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