Stand-alone true pitch shifting vibrato for guitar

[Willabe]

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     

[sluckey]

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!

[Willabe]

thanks ,,,,,,,,for the  topic and this layout.

It's Sluckeys baby.    

Tom your coming in at a good time with Sluckey refining it a little more.



                      Brad    

[sluckey]

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!

http://home.comcast.net/~seluckey/amps/warbler/warbler.htm

[tubeswell]

And some new sound bytes please.

[sluckey]

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.

[Tom_Hull]

thanks ,,,,,,,,for the  topic and this layout.

It's Sluckeys baby.    

Tom your coming in at a good time with Sluckey refining it a little more.



                      Brad    

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  :dontknow..:so back burner for the moment
i .need to finish one of three more amps  .

tom

[Willabe]

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      

[Willabe]

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     

 

[sluckey]

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.

[Willabe]

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      

[HotBluePlates]

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.

[Willabe]

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     

[Tom_Hull]

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

[Willabe]

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


               Brad     

[sluckey]

i am working on the hammond board in the unit..

Ooh, I don't envy you! 
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.

[Tom_Hull]

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

[sluckey]

that there is no power to your pin 6

Look again after a cup of coffee.

[Tom_Hull]

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

[sluckey]

Just to be sure I'll shine a light on it...

[Tom_Hull]

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. ...

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..

tom

[Willabe]

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     

[Willabe]

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      

[sluckey]

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.

[Willabe]

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      

[sluckey]

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...

[Willabe]

Just had an idea, don't know why I didn't think of it before.          

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      

 

[Willabe]

I don't like A because the pot is backwards.

That was to keep the tubes gain constant and just limit the drive signal.    

But A and B both have dc on the pot.

Oh, yes, I see now. Because it's bootstraped.    

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    

[Willabe]

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.    

I think their all worth a try.      



                  Thanks,  Brad            

[sluckey]

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.

[Willabe]

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      


Edit;   Fixed tone control drawing wiring.

[sluckey]

I don't think your tone control will do what you expect. Try this...

[Willabe]

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    

[sluckey]

What's Dakaware?

Dakaware is a brand name. Their chicken heads look classier IMO. More expensive though.

[Willabe]

Oh, ok.

Got better looking lines/shape to it. + raised back/top. I like them.


              Thanks,    Brad   

[sluckey]

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. 

[Willabe]

IIRC, AES sells them. But there's the hitch in the giddy up, as always. $$


             Brad     

[sluckey]

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.

[Willabe]

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     

[Willabe]

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.    

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        
 

[sluckey]

You're thinking waaaay too much. Put those idle hands to work.

[Willabe]

I need my face plates so I can drill my chassis!     

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        

[sluckey]

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.

[Willabe]

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.   


             
                Brad     

 

[sluckey]

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.

[Willabe]

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        

[sluckey]

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! 

But mainly, I'm just avoiding answering that question. 

[Willabe]

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.    

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.  

It's a valid question.    


                Brad              

[sluckey]

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? 

[shoggoth]

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...