Colorsound Vocalizer vero

[Ronan]

Hey thanks jimi, the description is fine, don't worry about a layout I can work that out. Tomorrow I'll order some parts for that vocalizer and the lib com. Peace Bro.

[pinkjimiphoton]

ok bro, no worries. i DID whip up a layout for ya tho, lol...but it's gotta be refined a little bit, as i was tired.

the 22k pot you can get on ebay outta england for around 3 bux plus shipping. only place i found one...it's plastic, but works great.

[pinkjimiphoton]

hey dino, i think that this is supposed to be a 2.2k dual pot, not a 22k...see the mouthmeister thread.

i think i was sweeping right past it in the first little part of the rotation...or, it's some weird taper...maybe audio?

[digi2t]

I've zoomed the drawing, but I didn't see any decimal between the two 2's. I've commented on this, on the Mouthmeister thread. Actually, now that I think about it, those plastic pots you're using, are those conductive plastic? Could that be messing with the circuit? Just a shot in the dark here.

[digi2t]

hey dino, i think that this is supposed to be a 2.2k dual pot, not a 22k...see the mouthmeister thread.

i think i was sweeping right past it in the first little part of the rotation...or, it's some weird taper...maybe audio?

I've been thinking about this, and maybe there's another way. Case in point, the Ludwig. Why is there a resistor on the treadle pot? Maybe to change the taper/sweep? Check this page out; http://www.jt30.com/jt30page/potfix/, http://www.geofex.com/Article_Folders/potsecrets/potscret.htm, or http://gaussmarkov.net/wordpress/parts/resistors/resistors-6-mods/. They talk about using resistors to "change" the taper of a lin to a log. To some extent I've done the same thing with the Bias pot on the Skyripper, and Parallel Universe. In these cases, I've used trimmers as VR's, and soldered them directly to the lugs of the pots. If you look at this picture, at the second row of pots (from the top), right in the middle above the board, you'll see a pot with a trimmer soldered directly to the lugs.



This is the Bias pot of the circuit. Why did I put a 25K trimmer here? Because I couldn't find a pot that had just the right sweep/taper for the job, so I cheated. I used a trimmer larger than the pot resistance, and then started dialing down. At some point, my B25K started to react like an "A17K". By tweaking the trimmer, I managed to stretch out the taper, giving me a sweep, and get a curve to my liking.

As R.G.'s page points out, I'm essentially using the trimmer as a "taper resistor", except in this case, my resistor is adjustable . It might be a way to get around the sweep problem, and tailor it to your ears as well.

Then... maybe, different taper resistances for each pot?  

[digi2t]

Hi bro,

Maybe try this; When the heel is down on the pedal, stick a resistor between the wiper lug, and the lug that the wiper is next to, in the heel down position. Try 20% of the pot value, so 22K x .20 =  4.4, so lets say a 4.3K to start. This should stretch the taper out more in the first half of the travel (going from heel to toe), like an audio taper. Like in this "B" plot;



The percentages represent precentage of your pot value, so if you really want to stretch out the first half of the travel, then go with 10% then, or 2.2K.

The reason I mentioned using trimmers (my fav) is because you can cover a range of resistors with one part, and fine tune. I generally use a 10K or 25K trimmer.

Do the same to both pots. You might find that you'll get a nicer sweep. If it does work, then I can maybe incorporate a spot on the vero where taper resistors can be added to suit personal tastes.

And if you're wondering about plot "A", that's the sweep you can achieve by using 2 resistors, one between lugs 1 and 2, and another between lugs 2 and 3. Then you can shape each side of the taper from center. Could be a real cool way to shape the sound of a wah to the travel  .

[pinkjimiphoton]

dude!!! that is so hip!!

sorry didn't get tot hit the pedal tonite, too busy making toothpicks out of logs today to have any kind of life. at least i got the firebird done for the show tomorrow nite.

i will try and hit this on saturday when i get some breathing room and have a couple bucks in my pocket. the trimmer idea is wicked simple and valid i think, and may solve the issue. i really do think the coloursound pedal is suffering from the same problem i had with the mouth meister. both have similar sounds (duh, i guess they should being FORMANT pedals, right pink? lol) and exhibited similar weirdness. we'll see what happens. i'm pretty sure the coloursound may well function with just a single pot if wired right. i bet when they put up the schematic something weird happened, or maybe coloursound themselves put the wrong values on something. it's gotta be something obvious i've overlooked or something.

we'll figure this out.

then build one with an uglyface in it.

[digi2t]

OK. I've been doing a lot of reading on wahs of late, and audio, or custom, tapers always come up. Never linear.

BUT....

If this pedal was supposed to be low at each end, and high in the middle, like the original schem shows, then I could understand the linear pot. Since you're not using it that way, audio taper would be the way to go. So, in this case, maybe we can just cheat 

[pinkjimiphoton]

that's the weird thing tho dino...it's high at each end, and low in the middle as per the schematic...but not in a real useable way...the hell position is maybe 1/5-1/10th the pedal travel, and then a wah from about half way up to toe down. that's almost the same thing that the mouthmeister was doing...that's why i'm thinking it's gotta either be an audio taper pot, where most of the travel is in the beginning and just a little at the end (maybe reverse audio taper? not sure how that works, maybe we should call the Resident Genius in for a consult if he can spare a few minutes) or it needs to spread that formant out over the useable range...remember rg said the formants occur at specific frequency ranges when we were working with the pII...if that's the case, since 2.2k is about 1/10th of the pot we're using, that should work out.

maybe something like this:

http://www.allelectronics.com/make-a-store/item/PD-222A/2.2K-LINEAR-DUAL-POTENTIOMETER/1.html

or this...

http://www.westfloridacomponents.com/P029/Dual+Potentiometer++2.2K+and+25K+Carbon.html


the second one looks interesting!!

i ordered one of the first ones, just for the heck of it.

[Keppy]

It's possible you need a W taper, like in a TS. The wah I gutted to make the Phase II had a W100k pot in it.

A W taper is reverse audio until the halfway point and audio taper after that.

[pinkjimiphoton]

i think that's the marking on the pot i took out of the pyle bro,...but it's 100k, and too much wah pedal travel. over 10 k it turns into a wah pedal. weird!!!
i tried using a resistor to make it different, but it plain didn't work...will have to play with it when i get some time.

[Keppy]

Oh, I wasn't suggesting a 100k, just pointing out that a W taper is something found sometimes in wah effects and other filters.

[pinkjimiphoton]

hey dino, i revisited this today to see if i could figure it out..

as it turns out, i think the schematic is wrong. it's working now, i set it up like this....

think of the terminals of the dual pot like you would a dpdt

1   6
2   5
3   4

so i wired it like this (as per your layout color code):

1 purple
2 blue
3 GROUND
4 no connection
5 gray
6 white

this way definitely works, either terminal one or 3 needs to be connected to the purple wire, and the other side needs to be grounded, or it plain doesn't work. but pretty much either way, 1 or 3, does. if you jumper them, then the effect stays stuck in the bass range, sounds a lot like a pII heel down.

but diggit...at the top of the range of the treadle pot, if you go just a little too far, it goes to ANOTHER "heel down" position, and a much quicker sweep thru another formant...maybe the last 5-10% of the pedal's travel. so the secret appears to be to move the pinion gear around so that at full toe down, it's hitting the peak before it dumps into the next formant. when you build it, you'll see what i mean. it's about an "octave" higher, and is the one i'd probably go for if i knew what i was doing and designed this pedal. the formant it has now is a solid oooohwahhhhhhhhhh. so it's working bro.

my previous reports i think were operator error, trying to get that tiny area at the end of the pot's travel to be the far larger sweet spot it was supposed to be. i wouldn't have learned this without the mouthmeistor i don't think.

so anyways...seems to be good bro!

[digi2t]

Hi bro,

Just got back in, I'll give you a shout tomorrow.

I've been studying the pictures of the originals, and I think you must have it wired right. I say this because by my observation of the two different pics of the originals. In one pic, I truely don't believe that a bare wire would not have been used as a jumper on the pot, unless for grounding. Why risk shorting a signal with a bare. I think in one pic, they're grounding the lug, and then jumping the bare to the pot case. In the other pic, I believe they folded the lug to the case, and soldered the bare and lug to the case saving the jumper.

I've stared at these pics until my eyes have gone buggy, and in my heart of hearts, I think this is the case. This would also backup your build. I'm slowly getting geared up to do this build, and if mine works this way as well, it will validate my assumption.

As for the pinion position, the Ludwig does the same thing, so I understand what you're talking about. I will be testing putting resistors on the pot though to bend the taper. Should be interesting to see what results. Found a neat pot taper calculator on Joe Davisson's site; http://www.diystompboxes.com/analogalchemy/emh/emh.html .
The "Linear Pot" page is for converting log pots to linear, and the "Taper Pots" page is for converting linear to log pots. You can also calculate the percetage of taper as well (to within reason!). Cool stuff.

Talk tomorrow,
Dino

[pinkjimiphoton]

k bro....right now i'm not gonna mess with it too much...it works, sounds good, that's good enough for me.

but....i don't really LOVE the circuit...it seems a bit muddy compared to other wahs, and it's high end is about an octave less than a crybaby. that's why i was thinking the other part of the pot's travel was the sweet spot we were looking for.

i am seriously wondering, after looking at the schematic for hours, where it says heel and toe by the 22k pot, if it's SUPPOSED to "wha" at each end from the middle tho.

i don't think it works really well like that, but maybe that's how it's supposed to be?

man...if we could find someone who actually had one to compare, that would be so awesome..

don't get me wrong, it's a nice sounding pedal...and fair's fair, i used it at the gig the other day set up wrong...so maybe my perspective will change when i get to mess with it a little bit more.

anyways...i'm home tonite chillin' bro, if ya get a chance, gimme a hollah!   sorry i couldn't talk earlier, it's been one of them days...again...sheesh.

[pinkjimiphoton]

Hmmm...
Technology of the Colorsound Vocalizer
Input signal to sections A and B of opamp. Input impedance 120K paralleled with 100K. Input noninverting to fuzz opamp 1-2-3, inverting to clean opamp 4-5-6, with gain of 3.3 to noninverting/clean. Gain of 1+1M/27K on fuzz, clipped by diodes. Clean and fuzz blended/selected by cross-signal blend pot. Blended signal to both formant filters in parallel; Section 8-9-10 being F2, section 12-13-14 being F1. Filter frequency set by dual 22K pot. Filters are resistor-to-ground multiple feedback bandpass types. See The Technology of Wah Pedals, http://geofex.com/Article_Folders/wahpedl/wahped.htm and "Human Voices and the Wah Pedal" http://geofex.com/Article_Folders/wahpedl/voicewah.htm. F2 rises monotonically with pot position. F1 uses the same trick as the EH "talking wah" of tying both ends of a pot together to get a resistance that rises, then falls. The resistance range was not enough, so this resistance is used to control the 3080 OTA set up as a current controlled resistor. PNP transistor converts pot position to variable current into the OTA's bias pin. Two filter outputs added in parallel in a resistive adder for the output.

Simple. Cheap.

Hitting particular formants will be random-ish with part variation, but should be interesting. Can be tuned for better. Q changes with frequency, probably not too badly.
Much like the EH talking way or a couple of the wah-antiwah setups noted other places.  Likely to lose some bass response with low notes because F1 is a bandpass, not a lowpass filter.

hmmmm....now i'm wondering if the 3080's bad....gonna try reversing the wires on the pot and see if it still works. cuz wired as shown on the schematic has gotta be wrong, unless either the vero's wrong (i've looked it over 30000000 x and it looks to match the schem 100%) or one side of the 3080's bad.

onwards and upwards.

[digi2t]

Having read R.G.'s article, it seems plausible now that while one pot sweeps one formant (F2) from high to low, the other (F1) sweeps up in the middle then back down. That would explain why one pot has lugs 1 and 3 jumpered together (purple wire). Maybe the original schematic is correct after all, even if the pics are too vague.

I've been studying the Colorsound Dipthonizer circuit, and I've spotted some similarities.



If we look at the lower right side, we can see the formant sections (4558 ic). In the Vocalizer, they use half of the 4136. One difference I see, is that in the Dipthonizer they use two 1n5 caps for F2, while in the Vocalizer they run parallel 220p and 680p caps. That's 900p, not too far from 1n5. I guess that's how they tuned the formant to get a vowel pronounciation. On the other formant, both pedals use 4n7 caps. The 3 diodes to ground are also present. In the Dipthonizer, they go directly to ground, while in the Vocalizer they have to go through a 12K resistor to get there. I'm wondering if tweaking the 12K will make up for slight differences in the forward voltages of the diodes? Maybe a trimmer here? I think when I start putting this together, I'm going to sub in trimmers for the 1K2 (purple wire), the 12K (below diodes), and the 3K (above tranny). Set them to the schem resistances, and then tweak them to see if I can "smoothen" the up and down sweep through F1. Maybe during production, certain components were pretested for the exact tolerences for this circuit. I think you need to be spot on to get the right sound here. Could be why this pedal is so rare. Too labour intensive to find just the right resistors and caps to make it work just right.

I've also read "elsewhere" that changing the 2K2 resistor going to pin 5 of the 3080, changes the "color" of the sound. A sort of Q adjustment perhaps? Mind you, this was taken from the Dipthonizer notes, so I don't know how it would work on the Vocalizer. On the Dipthonizer, they add a 4K7 resistor in parallel to a 10K, wired through a switch to change the frequency sweep.

We can also see the fuzz section (1/2 of a LM324 in the Dipthonizer, 1/2 of the 4136 in the Vocalizer). Playing with the resistor value next to the clipping diodes (feedback resistor?) will probably change the fuzz intensity. Could even try different diodes here, although I'm not sure if it will have adverse consequences on the vocal side of things. In the Dipthonizer schem though, we find a .0022uF cap bridged across, along side the diodes and resistor, perhaps to brighten the tone.

Looking at both, I get the impression that if you combine the two, you've got an IC version of the Ludwig... Dipthonizer, LFO sweeping vowels, Vocalizer, pedal sweeping frequencies... I dunno, I might be dreaming here 

Anyway, that's my 2 bits, FWIW. Then again, I might be out to lunch as well. If that's the case, I'll have the pastrami on rye, double mustard, to go.

[pinkjimiphoton]

hey dino, was talking with boris on another forum, he said this this morning...maybe it IS right as per the schematic:

"you have in your configuration 2 wahs in paralell.....going up and down togerher....different capacitors in each ,so therer is no wowels happening there....that pot lugs should be connected to V/2 throught 1k2 resistor.......and than through transistor you controll ca3080 which acts like variabile resistance for lower filter.......so on heel position one filter is all in high frequencies,other one goes from bass to high(in the middle of travell) and again to bass freq.......so there should be taler effect.........

You could allways add little toggle switch to choose your sound or original one.......I would like to make it talk so soon I will make one too.

You could check what is happening around Ca3080 and tranny ....is there voltage swinging on pin5............"

so i'll try to check it out later today, and will report back my findings..

[digi2t]

OK bro.

I'm thinking the schem is right as well. I'm also trying to find any info on the tranny. I was told that it was your garden variety PNP germ. I'm wondering if a silicon tranny would make any difference here, but again, I was told that it had to balance with the total forward voltage of the 3 diodes. I think it's in this thread, earlier on.

Check the 3080 though. That guy boris seems to know his shit. He's put out a ton of info on the Dipthonizer clone.

[pinkjimiphoton]

will do bro....trying to sort out some other probs with the "one chip chorus"...and check the ludwig thread....