*"new" Tweed BluezMeister with 5879 OD

[SILVERGUN]

OK, I went back and edited that post and added my version of T's schematic....

Biggest changes you should see are filtering values, dropping resistor value (between A and B), and screen resistor value,,,besides just basic tube substitutions....some small cathode bypass cap value changes...that's it

I set up the screens like that for use with 6K6GTs,,,and to try to "simulate" some of the sag effect that is lost by using the SS rect (I based the value off of the 5E3), and the 10 watt rating of that 4.7K resistor, is overkill, but cheap, low heat insurance

Sorry I haven't taken the time to work in SCH,,,it's just easier for me to cut and paste, and this schematic will be changing.

[SILVERGUN]

I just posted a short demo clip of how the amp sounds on the board as of Sat. 2/1

I bought a new little recorder and wanted to test it out.....let me know if there is anything else you would like to hear.

I'm using a slight delay in the loop with the MIX pot installed.

http://www.el34world.com/Forum/index.php?topic=16636.msg164501#new

http://www.soundclick.com/player/single_player.cfm?songid=12671470&q=hi

[SILVERGUN]

I listened to the clip a couple of times and realized that I should explain a couple things....

- 5879 is switched in the whole time, no cathode bypass cap, trim pot cranked to 8
- bootstrapped cathode follower 12AT7
- Input volume on 5, treble 6, mid 7, bass 5, mid-boost switched on
- 10K shared cathode resistor in the PI, used as a power dampener, per sluckey's scrapbook (18 watt switchable power dampener)
- 12AT7 phase inverter tube
- 6K6GT power tubes installed with "master" vol. set on 6.....pretty bearable volume, sitting right in front of it
- Celestion G12H-30 in the open back, top half of one of my 2x12 cabinets

- Parallel FX mod with Mix pot on 3, and slight delay in loop....carried over from this thread:
 http://www.el34world.com/Forum/index.php?topic=16606.0

[tubenit]

First of all, VERY nice playing! You have some very cool chops.   

I think the amp sounds really excellent. You're getting what I would call that "vowel" tone, very sweet harmonics  and some very very nice sustain/blooming.

I agree with you that the speaker probably isn't the best choice for it. I've tried an Emminence Cannabis Rex, Emminence  Texas Heat and an Emminence Red, White and Blues with it.   Each of those sound good to me.  The CR and the RW&B would be the smoothest.  The Texas Heat gives it some "Fenderish" honk, IMO.

THANKS a bunch for sharing the soundclip.  Really enjoyed hearing you play. Very tastefully done.

With respect, Tubenit

[Jack_Hester]

OK, I went back and edited that post and added my version of T's schematic....

Biggest changes you should see are filtering values, dropping resistor value (between A and B), and screen resistor value,,,besides just basic tube substitutions....some small cathode bypass cap value changes...that's it

I set up the screens like that for use with 6K6GTs,,,and to try to "simulate" some of the sag effect that is lost by using the SS rect (I based the value off of the 5E3), and the 10 watt rating of that 4.7K resistor, is overkill, but cheap, low heat insurance

Sorry I haven't taken the time to work in SCH,,,it's just easier for me to cut and paste, and this schematic will be changing.

I saved your schematic (dated 22Jan), to compare with Tubenit's.  You don't have your mods drawn on that one.  Is there another posted that does? 

Really great sounding clip.  I can only hope that an octal version comes close.  Breadboard may come first.  Thanks again, for that inspiration.

Jack

[SILVERGUN]

I saved your schematic (dated 22Jan), to compare with Tubenit's.  You don't have your mods drawn on that one.  Is there another posted that does? 

No,,,, and thanks for reminding me...
I'll update and post shortly.......there are definitely a couple changes worth noting.

Thanks for the kind words Jack, and keep up the good work yourself sir.

[SILVERGUN]

OK guys,
As far as I can tell, this is the way it appears on the recording.....
Changes from previous schematic:
- 12AT7 cath. follower after 5879 (quieter than the 12BZ7 I had in there)
- 12AT7 PI
- 10K input resistor
- Parallel FX mod with 100K MIX pot
- 390ohm cathode resistor on 6K6 power tubes to bring dissipation down to 8 watts per tube....was over 9 watts with 270ohm
- 10K shared cath. resistor on PI as a power dampener "trick"
- I had tried a cathode bypass cap on the 5879 and thought it was a keeper, but then during recording I was looking to drop some noise, and I found that I thought the 5879 sounded better without it (less boxy/gritty)

I think that's everything for now........back to recording tonight  

[Jack_Hester]

I've got a couple friends that I have sent Tubenit's soundclips to, from time to time, as they like his playing style (but, don't frequent forums).  Yours will go on the same mailing list, as this is a keeper, too. 

Another friend who plays lead in a band, will most certainly want to hear this.  He's been playing for something over 30 years now, and he will love the sound of this amp.  Especially, since he's just recently started building tube amps.  A really good technician, and excellent guitarist.  The amp building all came about last year, when a Vox combo amp of his went South on him.  And, because of the circuit board construction, and the high quote to fix it, he and I had a discussion of putting a basic clean amp inside the cab, and running his effects through that.  He built it in it's entirety, in his kitchen, on the counter.  And, has performed with it. 

Well, that snowballed into a second clone head build of a Marshall JCM800 (I don't remember the model), that has since been tweaked and modded.  He's away on a job in Florida (we're in N.Carolina), but I had mentioned your building breadboards.  When I told him that I was drawing the beginnings of one, he got excited. 

I'm thinking that when he gets back, a second breadboard will be in the making.  Then, the serious tweaking will begin.  So, between Tubenit's amp designs, and your breadboarding (with soundclip), something else will begin to snowball.  He's a copier/paster, like yourself.  I'll just have to keep up with his drawings, as well. 

Anyway, I'm sending him the soundclip is just a minute, and I'll let you know his response.  Both of y'all keep doing what you're doing.  Have a good one.

Jack

[SILVERGUN]

I posted this over on the sound clip thread, BUT I feel so strongly about this, that I figured I better put it here too....

I tried a Celestion Vintage 30 in place of the G12H-30 Anniversay speaker that I have been using,,,and it just absolutely sounded terrible to my ears, with this amp.

It brought a very nasally, harsh, sharp tone that I didn't find fitting at all.

If anyone builds this amp and plugs into a V30 they are going to be missing the great tone that this amp possesses.....sadly.

[tubenit]

The challenge I had with the bootstrapped 5879/CF arrangement was I could not get a balanced clean to OD tone.

So, I am wondering IF there is another way of approaching this besides the typical DPDT switching on Dumblish amps.

Geezer came up with the idea of "pseudo-channel switching" on one of his HoSo56 amps:
http://www.el34world.com/Forum/index.php?topic=10999.0

You'd have two relays that switch simultaneously.

So here is what I am thinking ....................... for clean have  things set like:

vol 3       trim 3       OD vol 5     FX level  8

then for the OD setting:

vol 7      trim 6        OD vol 5       FX  level 4

I am sure these settings would need to be tweaked but that might be a starting place to have a clean tone for rhythm and a lead tone for
playing lead.

Don't know if you could breadboard this and/or how easy it would be to do ????

With respect, Tubenit

[tubenit]

SILVERGUN,

You could check this idea out on your breadboard by simply experimenting with adjusting all the settings to see if you can get a reasonable clean tone first, ...................... and then ........................ adjust settings to see if you can get a good OD tone with nice sustain around the same volume or just slightly more volume for lead.

IF this works reasonably well, .............. could you record a rhythm and lead on clean and then the same song with OD settings for us to
hear?

With respect, Tubenit

[SILVERGUN]

That's kinda how I was thinking of approaching it.....except, I was picturing set value resistors across some of those same points...
So the resistors would be in parallel with the pots (volume, trim, etc...) and/or grid leak resistors for the clean tone...
And then you switch to your OD tone and it lifts a "shared ground" connection for a couple of the paralleled resistors......so that a couple points get switched in/out at the same moment, with one switch,,the same one we use for clean/od....but a 3PDT (if need be).... for guys who don't want to mess with relays  

Is that worded well enough that you can picture what I'm suggesting?

Your idea with the pots would be a great way to determine what those resistor values need to be, and then the amp could be built without all of the extra pots....and I should be able to lay that out on the board without too much trouble.

Either way, I like the way you're thinkin'  

AND, I'm still kinda picturing this amp as a "pseudo" 3-channel....with CLEAN, OD, and SOLO (with the solo just being a different switchable "master" setting,,, that might also bring up the delay MIX  )

For right now,,,I'm still tweaking OD tone, and I need to take that as far as I can and then eliminate some of the gain to "create" the clean tone...
The front end drive of those first 2 gain stages has a lot to do with the OD tone that I really like......so somewhere along the way, I gave up any sign of a normal clean sound....because when I switch out the 5879 it's still a driven tone.

I hope this makes sense.....I wanted to get out some thoughts so you know where I'm coming from...
I'm starting to see the 5879 as more of the "icing on the cake" rather than the main gain stage  (partially because of noise, but also partially because there are plenty of gain stages available to draw OD from.....it might take dropping (switching out) a cathode bypass cap on one of those stages to get back to a good clean sound  

Just thinking out loud....  

[tubenit]

,,,I'm still tweaking OD tone

When I tried the 5879/CF bootstrapped OD,  I didn't use it because of the clean to OD volume issue.

Having said that,  I thought it sounded good BUT I also thought it could benefit from the OD tone control that I use on the original TBM and D'Mars.  I thought the tone control added to OD might dial in "that" tone.

with respect, Tubenit

[SILVERGUN]

I also thought it could benefit from the OD tone control that I use on the original TBM and D'Mars.  I thought the tone control added to OD might dial in "that" tone.

I saw that in one of your drawings.....haven't needed to try it yet, but I'll keep it in the holster


Here's a little drawing (from my idea above) of the proposed switching to knock down some of the gain in those first stages when you have the switch in the clean position...
- the added 500K across the volume pot drops that to a 250K pot
- the added cathode resistor cap combination drops the resistance, AND adds the cap for the OD tone

I think I have the switch drawn correctly for what I'm trying to accomplish...

I think this might help with the clean tone,, BUT, I think we would need another way of adjusting the 2 volumes in relation to one another

EDITED- fixed incorrect switch wiring

[tubenit]

I think we would need another way of adjusting the 2 volumes in relation to one another

To me, that is the primary concern and issue. 

With respect, Tubenit

[SILVERGUN]

To me, that is the primary concern and issue.  

For me it's the amount of drive that the clean channel retained when I would switch out the 5879....it's definitely a see-saw effect of trying to find a good middle ground


Were you finding that the OD channel was much louder than the clean channel?....I have been able use the OD volume to balance the 2,,,but that is a compromise as well...

I'll just continue to try ALL of these things in an attempt to get it right.....it's not that far off

[tubenit]

Using the "normal" 5879/CF that is not bootstrapped, I have no issue getting a great OD and clean at the same volume.

The bootstrapped version is so MUCH louder, that I could not find a good OD tone that balanced the clean tone volume. 

In other words, the bootstrapped version has a GREAT OD tone but the "good tone" was so much louder then the clean.  I could get an OD tone that matches the clean volume but it didn't sound good because the OD was so "reduced" in it's tone.  Hope that makes sense.

With respect, Tubenit

[SILVERGUN]

The bootstrapped version is so MUCH louder, that I could not find a good OD tone that balanced the clean tone volume. 

In other words, the bootstrapped version has a GREAT OD tone but the "good tone" was so much louder then the clean.  I could get an OD tone that matches the clean volume but it didn't sound good because the OD was so "reduced" in it's tone.  Hope that makes sense.

Yes, and I agree....
The OD tone does sound best when the OD volume control is above 5, and it does create a "balance" issue

Are you running a cathode bypass cap on the 5879....removing that might help, and I've found that when bootstrapped I seem to get just as much "drive", with a little less volume,,,as compared to not-bootstrapped and using a cap

You know me (I like OD), and I seem to actually like the 5879 better without the bypass cap 

[tubenit]

I preferred the bootstapped CF approach to not have a cathode cap. It sounded smoother to me. 

Tubenit

[Tone Junkie]

Gentlman I may be wrong but I thought in a differant thread Slucky talked about using a voltage devider to pad down a signal to better match the loudness of two channels coming together. In other words dropping a bit of the signal from the OD section to better match the signal from the clean section.
 I tried to find the conversation to referance from, but Im at work and dont have my saved files to pull from.
Maybe we can get some off those guys to chime in .I might be totally off base and it wasnt him but I thought it was.
 I read from so many places trying to learn I get them mixed up sometimes. But If we can find away to drop some of the signal without changing the treble and bass characteristics, that might be the way to go.
Bill

[SILVERGUN]

But If we can find away to drop some of the signal without changing the treble and bass characteristics, that might be the way to go.

Please don't hesitate to chime in....the challange here is that the clean signal is one volume and then we are just adding the 5879 to that signal to make the OD tone, so inherently, the OD channel is going to be louder than just the clean channel.....
I am still thinking of a work-around, BUT I'm also still trying to get the OD tone just right,,,,so it doesn't make sense for me to try to balance a volume that isn't set in stone yet....and I may eventually choose to just use this circuit as a single channel amp, without worrying about the clean tone. I would like to see it be a balanced 2 channel amp, but I can't wrap my head around how to make it happen.

I'm so far off base that MY last idea was going to make the clean volume even lower, by reducing the gain to try to get to clean tone "right".

I'm thinking that T's original design is the best balanced version of this amp.

[Tone Junkie]

Im really interested in this also because I love the sound of the 5879 overdrive in this circuit Ive built the very 1st version of this and loved the sound of it.
 I even went on to use the clean channel at the time which wasnt all that clean with the fat 3 gain stage version as a lead channel in a blues amp. I loved the sustain and blooming  that one had in the clean channel.

But the high gain guys have to contend with this but they pad the signal by dropping some to ground with voltage dividers between stages.
Ive read discussions, but I still dont understand how that works or for that matter havnt been shown a clear example of how to apply it to a design.
Ive asked the question several times but I get a vague answer without a visual schematic to show me an example .
 Sadly thats what I need to understand these things Im a visual guy.
Give me one example of how something fits in a circuit and why, and Im good to go. When I get home I will look through a bunch of my high gain schematics and see if I can find a common padding scheme between the high gain channels and the clean channels. At least maybe I can find a few examples post them and the really knowledgable guys here can explain them. Might be helpful might not
Thanks Bill

[jazbo8]

SG, did you build your version with all the OD pots? There are three - OD Trim, OD Drive and OD Volume. I thought the idea was to set the trim and drive then use the volume to match the level with the clean. Then again, I only played the amp at modest bedroom levels, so I never had a chance to crank it up, so perhaps the OD characteristic changes and requires re-adjustment of all the settings, which would be a pain for live situations.

[TIMBO]

Great job boys, I built the bogner XTC and having multiple channels the job of keeping then at similar levels I guess was a bit of a problem for the designers. The three stage CLEAN channel is one way to up the volume to match the OD.
Looking at REPLY #59 I guess you could use that schem and add a extra two triodes between the volume and level pots.

[tubenit]

the high gain guys have to contend with this but they pad the signal by dropping some to ground with voltage dividers between stages

You don't need voltage dividers in this design.  You have a volume, OD trim, OD volume, FX send, FX level.  Essentially you have 5 volume pots to control gain stages.  IMO,  I'd rather have that then fixed voltage dividers. 

I typically will use a voltage divider (like you see between the FX send and FX return) when I don't have room for a pot on the front of the chassis ............ OR it's an area that I never adjust the volume anyway.

With the 5879/CF bootstrapped,  I still think the answer is Geezer's "pseudo-channel switching" in order to get a volume balanced clean to OD.  

It would take about 5 minutes to figure out if this idea would work by setting the volume pot at 3 with FX level at 7 ............ & then change it to volume at 6 and FX level at 3.   How does the OD sound like that?  Is the volume between clean and OD balanced?  Switching two DPDT relays at the same time would allow one to create 4 volume pot changes simultaneously.

With respect, Tubenit

[SILVERGUN]

Great responses GUYS,,,I really appreciate the attention and the desire to help 

SG, did you build your version with all the OD pots? There are three - OD Trim, OD Drive and OD Volume. I thought the idea was to set the trim and drive then use the volume to match the level with the clean. Then again, I only played the amp at modest bedroom levels, so I never had a chance to crank it up, so perhaps the OD characteristic changes and requires re-adjustment of all the settings, which would be a pain for live situations.

No jaz,,mines only got the TRIM and VOL.....I built it pretty similar to the first posted schematic on this thread, except I used a tube for the cathode follower....
The big problem with ME is....I like it better when they are all turned up,,,and that's how I've created this problem for myself

By using the lower wattage 6K6's and choking down the PI with the 10K shared cath. resistor, you can push all of those controls up to about 8 (including the MASTER) and still be able to sit in front of it  .....and that's where it really sings and sounds the best to me
BUT, at no point did I take the clean sound into consideration as I was just trying to max-out the OD tone

Looking at REPLY #59 I guess you could use that schem and add a extra two triodes between the volume and level pots.

REPLY #59 is THE BEST ANSWER....at least for me...I stayed last night and played around with it with good results....see below
 

[SILVERGUN]

With the 5879/CF bootstrapped,  I still think the answer is Geezer's "pseudo-channel switching" in order to get a volume balanced clean to OD.  

It would take about 5 minutes to figure out if this idea would work by setting the volume pot at 3 with FX level at 7 ............ & then change it to volume at 6 and FX level at 3.   How does the OD sound like that?  Is the volume between clean and OD balanced?  Switching two DPDT relays at the same time would allow one to create 4 volume pot changes simultaneously.

YES!...that's it...read on
First,,,T, I apologize for any aggravation that I may cause by taking your nicely designed amp, and brutalizing it....I have just enough knowledge to be dangerous  ....
Keep in mind that ---until yesterday I hadn't given the clean tone ANY attention at all and was just pushing the OD tone, thinking that I could always just go back and drop some gain and have a decent clean ....bad idea  ...but this is MY first 2 channel amp build

I stayed a while last night and tried to test Geezer's approach and it works exactly as you think it would.....it seems to be the only way to have ultimate control over both tones and their volumes...

So I'm gonna go back to what I was doing and continue tweaking,,,knowing that I will be able to get back to clean by using the method outlined in REPLY #59

I think it'll be time to create a different thread, so that I don't muddy the waters surrounding T's original design, any more than I already have 

[tubenit]

Hey man,  I love it that you take a design posted and approach it in a fresh way to make it something innovative and your own. I am fully supportive of that and have zero aggravation around that.  It's a good thing!

I think it's totally legit to just have a fully driven OD tone amp with no clean or a 2 channel amp that is moderate OD and then totally to max OD. It's all appropriate and good in my book. 

I really like the OD tone you got. It's excellent! No reason to change it.

I'm just curious whether you can keep the uncompromised OD tone .......AND dial in some clean (or somewhat cleaner) at a comparable volume.  That's where Geezer's psuedo channel switching idea got brought in.

Feel free to continue in this thread or start another. However you want to handle it is fine.  I like watching the evolution of these design ideas unfolding. I'll keep watching what you do with this with interest.

With respect, Tubenit

[SILVERGUN]

Hey man,  I love it that you take a design posted and approach it in a fresh way to make it something innovative and your own. I am fully supportive of that and have zero aggravation around that.  It's a good thing!

Thank you sir....I truly value your support and direction...

I have one MAJOR mistake to report:
-In my last schematic (with parallel FX mod), I had eliminated the FX send pot and opted for a fixed value of 10K in place of that pot...
Well, that value is way too low, and I had come up with it while tweaking the OD tone with everything cranked....with the amp set like that, 10K is OK because there is a huge signal there and 10K knocked it down real good.....
BUT, when you switch it to clean, there is not enough signal to push past that 10K and most of the clean sound was going to ground and I was left with a very thin, anemic clean tone,,,if I left that 10K in there

- I switched it out for a 33K to simultate a setting of 3 on a send pot, and that appears to be a much better solution

[SILVERGUN]

Here's a small update...
I've spent a lot of time recently, tweaking and tearing the circuit down to learn more about what makes it tick....only to back track and return the circuit closer to the original design  

It seems like I have changed every other value in the amp, only to revert back to where it was...

BUT, I spent a lot of time tweaking the effects return stage and the PI....because I thought it would make sense to push more current, by changing the bias point of the return stage.......
Well, by using the load line plotter, I determined that a more ideal operating point for the 12AU7 would be 33K plate load, with a 1.8K cath. resistor...
But in reality, I found that the increased current came with increased noise, AND  I seemed to be hitting the grid of the 12AT7 PI too hard (causing hiss, and then cutoff, at a higher FX return "Master" setting)

So I spent a lot of time trying to push the boundaries of that area, and wound up with the 100K plate back in there, BUT, I increased the cath. resistor to 4.7K.......AND, I also took away the cath. bypass cap, and that provided a nice reduction in overall noise, and lowered gain (which I really liked there)
I tried it with and without that bypass cap, and it didn't seem to affect the sustain/harmonic blooming

I think that this change is very notable, and might be something that T (or anyone else) would want to try......by lowering the gain in that stage it has enabled me to drive the 5879 harder but with less amplification of the resulting noise  

And that's what I'm suggesting,,,,lose the bypass cap, increase the cath. resistor, and drop the gain in the effects return stage of the 12AU7, so that you can drive the 5879 harder AND raise the OD volume pot, for more singing sustain, with possibly less noise...
Of all of the moves that I have made, this one seems to be the most beneficial to my ears,  for getting a "better" OD tone
It seems to have taken away some of the "boxy" gain sound that I thought I was hearing initially.....

[tubenit]

Hey man, thanks for the update and the tweaking info.  I'll probably try that in the next several weeks and report back how I like it.

With respect, Tubenit

[terminalgs]

I've been keeping up with the FX loop threads for the most part.   following with interest.

One thing I'd want to do in such a circuit would be to install a switch to remove the entire set of triodes and all their circuitry from the signal path when FX loop not in use. 

I sometimes use switched cliff style stereo jacks making use of the "ring" portion of the jack to do something -or not-, depending on its use. With such a switched stereo jack, when you insert a mono plug, the "ring" shorts to the "sleeve", which of course, is grounded.  When you remove the plug, the sleeve is no longer grounded.

When this thread's parallel idea came up, the following occurred to me:



values are generic.  they aren't meant to rework what you've done here.

the focus is on R1 and R2 together, and the Return jack's switched connections.

Regarding the Return jack:

when loop not in use:  (1) the "tip" is shorted to ground, and thus V1's grid is grounded. (2) the "ring" is open, not switched to anything; so  this means R1 and R2 are in series.  Signal at the Input travels directly to Output, bypassing the triodes and all its circuitry.  R1+R2 & R11 form mix resistors, so the signal is attenuated (in these case of the values, 50%).

when loop in use: the junction of R1 and R2 is grounded by means of a mono plug in a stereo jack.  Input would travel through the FX loop circuitry. ( and not through R1+R2, of course). R11 and R2 form a voltage divider, so signal is attenuated (in the case of these values,  33%).  The Mu of V1 is a possible tweak point as is R11 and R2, of course.

I set R1+R2=R11 thinking in terms of a single channel AB763, where in absence of the 220K mix resistors, one might want to attenuate the signal by 50% like a 2 channel AB763.  but, R1 and R2 don't have to be equal, and they could be bigger I suppose, like 1M each.


The Mu of V1, plus R11, R3, and R4 in addition to R1 and R2 would all be juggled to maintain similar signal levels for in use and not in use FX loop modes...


if all of this should be another thread, I'm happy to spin it off.  Or if, there is no interest,  I'm prepared for that as well!  (tho I'd certainly like to hear comments on the idea...)

[tubenit]

One thing I'd want to do in such a circuit would be to install a switch to remove the entire set of triodes and all their circuitry from the signal path when  FX loop not in use. 

I think you have a good idea with the cliff jack's shorting to ground.  I think that would work?

I used to use a simple mini-toggle DPDT but found that I always have the FX on since one of the main uses for me is to use the FX level pot as a master volume which works excellent in that regard, IMO.  So, I personally don't want the FX switched in and out. I would just switch the pedal into bypass mode instead.  Just a personal preference.

with respect, Tubenit

[SILVERGUN]

One thing I'd want to do in such a circuit would be to install a switch to remove the entire set of triodes and all their circuitry from the signal path when FX loop not in use. 

You're good on this thread term... we like ideas ...although this has the potential to spin-off to another thread...
I like this one,,,and was eventually going to try something like this as a way to switch an EQ in and out in the loop, as a solo boost, lead tone..

I don't need the loop to be active all the time,,,and it might be cool to just put a delay and an EQ there and be able to switch to those being activated, and just leave the pedals on all the time (and sitting on top of the amp)  ...

And I guess we "could" take the FX level pot out of the loop wiring (along the lines of your diagram), and just make it a true Master.

So for someone like me who wants to add the boost, along with the loop, we would use less attenuation when the loop is switched in,,,,at which point it becomes more of a "boost loop" than a fixed level effects loop

Just thinking out loud..............

[Jack_Hester]

I have a question about the preferred components that are used for these builds.  As an example of what I have on hand, I have an abundance of carbon comp resistors, that I use for repair as like-in-kind on old repairs.  I've used the same in scratch-build experiments.  For capacitors, I stay with modern, of like value (or close).  

Eventually, I want to include this information on my BOM's, as well as sources with part numbers.  I use a spreadsheet for easy copy/paste, and then print the same as a PDF sheet with the drawings.  The beauty of this is that this database can exist independent of any drawing.  I already have something of a database started, but not in the format that I want to build for this.  But, I can transfer most as I need.

Anyway, it would be good to include the best with comments as to reason for use, in my database.  Please comment with your preferred choices, and any reason why you like them.  Thanks for all help.

Jack

[tubenit]

If you are ordering parts from Hoffman than I would recommend Orange Drop caps in the clean and LTPI to power amp.

I'd use Xicon in the OD section and perhaps the FX also.  You could use Mallory 150s if you wanted in the OD and FX.

I typically use metal film resistors but I don't see why carbon comp wouldn't work? The CC's may be a little noisier at idle?

With respect, Tubenit

[Jack_Hester]

If you are ordering parts from Hoffman than I would recommend Orange Drop caps in the clean and LTPI to power amp.

I'd use Xicon in the OD section and perhaps the FX also.  You could use Mallory 150s if you wanted in the OD and FX.

I typically use metal film resistors but I don't see why carbon comp wouldn't work? The CC's may be a little noisier at idle?

With respect, Tubenit

That's the info I want to document.  And yes, Hoffman will go in as a primary source for these builds. 

I agree with the noisy CC resistors.  I don't mind this in some old amps.  However, the '63 B-12-N is my standard for quiet.  And, there are no CC's in that one, other than the PS.  All the more reason to use proven components. 

I'll follow your lead  on the placement of the componets that you've given.  And, hope that others will express their preferences, as well.  Thanks a lot.

Jack

[SILVERGUN]

Jack,
I always use metal film resistors, just because of the low noise quality...
I trust T's ears more than my own when it comes down to choosing components....
I try not to get too caught up in chasing "mojo" by using certain brands of components,,,,and if anything, I'll try an oddball cap here and there just to spice things up....
On one build I noticed that it sounded "better" if I used 2 caps in parallel to achieve the correct value....as if I was getting the tonal personality of each cap and they complimented each other....
here's the thread:
http://www.el34world.com/Forum/index.php?topic=16281.msg159408;topicseen#msg159408

And if I was going to build this amp, I would just follow T's layout, and component choices, because you just can't argue with the success of his builds......Although I might try a parallel cap or 2  

[tubenit]

I would just follow T's layout, and component choices, because you just can't argue with the success of his builds.

I easily trust the tone of my amps can be improved upon. And it's mostly subjective regarding tone and personal preference. I think what I have done is a reasonably starting point with the understanding these amps are intended to be tweaked for personal taste. 

I hope forum members will continue to experiment and mod the amp designs Geezer and I have done and report back what has worked, what has improved and what doesn't work. 

The collaborative efforts continue to help everyone's tone.

With respect, Tubenit