The Most Expressive Wah I Have Played...

[Gus]

Something else to measure is the total distance of the rocker travel and then compare between different wha bodys.  

[Paul Marossy]

I don't know if this helps or not, but I've got an old FrontLine Wah which is basically a Colorsound Inductorless Wah. The shell and the plastic part look the same as Paul's.
That uses a 100k linear pot, mine measures as 91k, a full sweep of the pedal covers a range of about 41k, which is virtually half the rotation.

I was mistaken, it's not quite 180 degrees. I measured the angles between both extremes with a 360 degree protractor. It starts out at 0 degrees and stops at around 135 degrees, right before it actuates the switch.

Hmm... Am I missing something here? I have a CryBaby with the pinion gear mechanism, that rolls the pot over 240 degrees and actually travels through the whole range of the pot. The only thing I did was that I removed the bumpers from each end of the treadle. The reason the colorsound wah has a wider sweep has to be because of the circuit and not the mechanism, I think.

I don't think it's because of the circuit. Comparing schematics, here are the only differences that I can see between the classic CryBaby circuit and the Colorsound circuit:

                                                         CryBaby            Colorsound

Input resistor                                        68K                   100K
Resistor to ground at inductor                82K                    100K
Capacitor to ground at inductor              4.7uF                 10uF
Resistor paralleling inductor                   33K                    none
Q1 emitter resistor                              470 ohm               none
Q2 collector resistor                               1K                     none

Both circuits use a 100K pot and a 500mH inductor, and everything else is pretty much the same otherwise. None of my CryBabys (I have several different versions, old and new) nor my Maestro Boomerang can match the sweep my Colorsound clone. The one very obvious difference between them is the distance that the treadle moves, which corresponds to how each wah sounds:

Crybaby, smallest sweep range, and least expressive
Maestro Boomerang, considerably more sweep range than a CryBaby has and is also more expressive
Colorsound, WAY more sweep range than the Maestro Boomerang and most expressive

I have been studying every wah circuit out there for a few years now, and I can only come to the conclusion that it has something to do with the design of the wah pedal shells and how much each one of them rotates the pot because all three of the aforementioned circuits are more or less the same when it comes to the core of the circuits.

[MohiZ]

If it is of interest, the Crybaby's maximum range with the rubber bumpers removed is about 4cm, measured as the distance between the tip of the rocker and the body. The rocker moves about 14 degrees from the toe position to heel position.

I don't want to argue with your experience, but I still think it's because of the circuit. Although it's basically the same, the slightly differing values of the components seem to make a large difference on the sweep range. I bought a Crybaby wah, and it had a very small and shallow sweep in stock condition. I've tweaked it for a few days now, and actually ended up with a sweep WAY too wide for my tastes, so I had to lessen it. The sweep now went from "wuuooaahh" instead of just "wah". In conclusion I noted that the gain of Q1 has an extreme effect on the RANGE of the sweep. Just try putting a 100k pot in place of its collector resistor. The downside of this is that it affects the wah's output volume drastically. I'm still trying to figure out a way around that.

Keep in mind, I haven't tried the colorsound wah.

EDIT: And, oh yea, the 2005 stock crybaby uses transistors that have a lot more gain than, say, 109b, that I've seen in some schematics. (I tried 109's in place of the stock trannies). I'd go as far as to say you're able to get a much wider sweep with these transistors than 109s. I can't tell what the new transistors are because it just says
"H MPS
418-
50 B"
on them, and I can't find any info on them.

[Paul Marossy]

If it is of interest, the Crybaby's maximum range with the rubber bumpers removed is about 4cm, measured as the distance between the tip of the rocker and the body. The rocker moves about 14 degrees from the toe position to heel position.

I don't want to argue with your experience, but I still think it's because of the circuit. Although it's basically the same, the slightly differing values of the components seem to make a large difference on the sweep range. I bought a Crybaby wah, and it had a very small and shallow sweep in stock condition. I've tweaked it for a few days now, and actually ended up with a sweep WAY too wide for my tastes, so I had to lessen it. The sweep now went from "wuuooaahh" instead of just "wah". In conclusion I noted that the gain of Q1 has an extreme effect on the RANGE of the sweep. Just try putting a 100k pot in place of its collector resistor. The downside of this is that it affects the wah's output volume drastically. I'm still trying to figure out a way around that.

Keep in mind, I haven't tried the colorsound wah.

EDIT: And, oh yea, the 2005 stock crybaby uses transistors that have a lot more gain than, say, 109b, that I've seen in some schematics. (I tried 109's in place of the stock trannies). I'd go as far as to say you're able to get a much wider sweep with these transistors than 109s. I can't tell what the new transistors are because it just says
"H MPS
418-
50 B"
on them, and I can't find any info on them.

Hey, I'm not arguing, it's just debating. 

I was expecting someone to bring up the absence of a resistor on the emitter of Q1 and that being a "big factor". It does have an effect on the circuit because if there is not enough gain, it won't sound good. But it's not going to radically affect the sweep range of any wah circuit. It might alter the frequency response slightly, but it's not going to be anything big.

On the CryBaby sweep range, I'm talking about a stock pedal with all of the bumpers still in place. In fact, all of the wah pedals I am talking about here are 100% stock, no modifications to them in terms of removing rubber bumpers or anything. Maybe I need to try that on my CryBabys because none of them excite me at all in their current states. And I have several different versions from new to old, from obscure to very common and a couple of modded GCB-95 circuits, some with Fasels, some with the "dreaded" stock inductor in the current GCB-95s. I even did a Vox "Grey Wah" clone. Not a single one of them excite me at all - they are just not expressive enough compared to other wah pedals I have. Another very expressive wah clone that I built is the Parapedal. But that is a completely different animal than any other wah pedal out there.

Anyhow, I will make a sound clip soon, you'll be able to hear that it has quite a sweep range.

[Gus]

Using the colorsound schematic I found at fuzzcentral

The first transistor has a grounded emitter two things this will affect compared to a crybaby.  One the colorsound can have more gain(depends on where the the transistor is operating, closer to cutoff less or sat more)  and the gain will be more nonlinear(more distortion) without the emitter resistor the crybaby has.  Two the inductor does not has a damping resistor across it.

Something to try is to place the colorsound circuit in a crybaby or adjust a crybaby circuit to the colorsound

Q1 collector voltages and Q2 emitter voltages should help.

[Paul Marossy]

Using the colorsound schematic I found at fuzzcentral

The first transistor has a grounded emitter two things this will affect compared to a crybaby.  One the colorsound can have more gain(depends on where the the transistor is operating, closer to cutoff less or sat more)  and the gain will be more nonlinear(more distortion) without the emitter resistor the crybaby has.  Two the inductor does not has a damping resistor across it.

Something to try is to place the colorsound circuit in a crybaby or adjust a crybaby circuit to the colorsound

Q1 collector voltages and Q2 emitter voltages should help.

The resistor in parallel with the inductor adjusts the "Q". To quote something from GEO: "Rq
This resistor is the primary determiner of the Q, or sharpness of the bandpass/resonance effect of the filter Values lower than 33K make the filter less sharp, reducing the quality of the wah effect. Values up to 100K contribute to sharper, peakier, more resonant tones. If it gets too sharp, the wah effect can be lost because it may not hit harmonics to emphasize." The absence of this resistor should make it a dull sounding wah then, but that is not what is happening in this wah because the "Q" sounds pretty high to my ears.

In the Colorsound circuit I built, using a battery that meaures 9.58V, Q1 collector voltage is 3.42V and Q2 collector voltage is 9.02 volts (small voltage drop thru the polarity protection diode I added). BTW, the transistors I used in my clone are similar in terms of Hfe, the gains are roughly equivalent to what it shown on the Colorsound schematic.

[R O Tiree]

I have a Crybaby (Rev H board) and I just filmed a little vid of it doing its thing...

CryPaby Pot travel

As you can see, I stuck a match-stick to the end of the pot.

About 135 degrees to the back bumper and quite a lot more if you compress it hard - about 170 degrees all told. The HotPotz II is a 315 degree pot so, for its "normal" range of travel, that's a 43% change in resistance (54% if you really rock hard back). Going with the numbers slacker provided above, that gives almost exactly the same - 45%.

All of which gives me a yen to pop a Colorsound board in there and see what happens

[R O Tiree]

MohiZ - They are MPS-A18, not MPS-418.

Datasheet here.

[Paul Marossy]

I have a Crybaby (Rev H board) and I just filmed a little vid of it doing its thing...

CryPaby Pot travel

As you can see, I stuck a match-stick to the end of the pot.

About 135 degrees to the back bumper and quite a lot more if you compress it hard - about 170 degrees all told. The HotPotz II is a 315 degree pot so, for its "normal" range of travel, that's a 43% change in resistance (54% if you really rock hard back). Going with the numbers slacker provided above, that gives almost exactly the same - 45%.

All of which gives me a yen to pop a Colorsound board in there and see what happens

Huh, I wonder why the two sound so much different then?  

MohiZ - They are MPS-A18, not MPS-418.

Datasheet here.

That's correct. A 2N5089 and MPSA18 have similar Hfe numbers.

[Exactopposite]

i have one of the red reissue colorsound wahs that came with the inductorless circuit.  Last year I converted it to the old school inductor based circuit and i am quite pleased with it. It's a monster of a wah pedal in my opinion.

I find it ironic that you posted this just as i decided to build a boomerang.

[Paul Marossy]

i have one of the red reissue colorsound wahs that came with the inductorless circuit.  Last year I converted it to the old school inductor based circuit and i am quite pleased with it. It's a monster of a wah pedal in my opinion.

I find it ironic that you posted this just as i decided to build a boomerang.

I still love my Boomerangs, and will continue to play them. They still are a fatter sounding wah pedal than any other wah circuit I have built, including the Colorsound wah. But the Colorsound wah's range exceeds anything I have seen to date.

[Exactopposite]

i have one of the red reissue colorsound wahs that came with the inductorless circuit.  Last year I converted it to the old school inductor based circuit and i am quite pleased with it. It's a monster of a wah pedal in my opinion.

I find it ironic that you posted this just as i decided to build a boomerang.

I still love my Boomerangs, and will continue to play them. They still are a fatter sounding wah pedal than any other wah circuit I have built, including the Colorsound wah. But the Colorsound wah's range exceeds anything I have seen to date.

After i build the boomerang (in the next week or 2) we can compare notes.

[Gila_Crisis]

nice nice, i've done the "Colorsound-mods" to my vox wah as well long time ago and i love it!!!! it's absolutely a LOT MORE VOCAL than a stack vox/crybaby!!!!!!

[Paul Marossy]

nice nice, i've done the "Colorsound-mods" to my vox wah as well long time ago and i love it!!!! it's absolutely a LOT MORE VOCAL than a stack vox/crybaby!!!!!!

Thanks for the interesting piece of info! I wonder just what it is that makes it so different then?

[Gus]

Two more things to add one is something I was told years ago.   Adjust the pot in the holder for the sweep you want.
   In the colorsound the pot is linear and if you rotate the body you can adjust it for more or less signal level to Q2 base.  If you adjust it so the wiper is at the end of travel at full up or down will give two different max signal levels to Q2.  One will have no series resistance after Q1 collector to "top" of pot  and wiper(max level) one will have series resistance after Q1 collector to the wiper of the pot (less max level).

The  next thing you can try is subbing in a say a 33k or 47K fixed resistor and a 100K trim pot(33k to 133k, 47K to 147K) for the 100K across the 10uf in the colorsound schematic.  The node of the 470K, inductor, 10uf and 100K is at "AC ground" so that spot should have the least affect except for the DC bias of Q1 and the loading of Q1 collector stays the same.

3.42VD at Q1 collector is kind of low but it is more toward sat so more gain for smaller signals(I have posted many times 1/2 of the power supply might not be what you want the web crap set the collector of Q2 of a ff to 4.5VDC is not alway what you might want)  Adjust the bias of Q1 collector up and down an note any changes in tone.  I would try a little lower up to 5 stuff like 3.2, 3.75, 4., 4.25 etc.  Could be 3.42VDC is what you want.

I would change one thing at a time and take notes

The distortion from Q1 could be a part of what you like, more distortion(harmonics) in the output of the wha

[Paul Marossy]

The distortion from Q1 could be a part of what you like, more distortion(harmonics) in the output of the wha

Aha, I see what you are getting at. Maybe that is the case here. I assume that would be due to a lack of headroom?

Could I see that happening on an oscilloscope? And if so, what would I be looking for? I assume that I could feed it a 1v sine wave and look for clipping on the output of Q1? It doesn't sound distorted at all when you're playing a clean guitar thru it, though. I have a feeling that you wouldn't be able to see this without a spectrum analyzer, although I have a function generator that I could tweak the frequency on while looking at the waveforms...

[Nasse]

Just used a calculator and I think it was 34 years or more ago I played trough that Colorsound, so no wonder if my knowledge is not so good.

I just did some rehearsal in geometry and my crude cardboard model gave 133 degrees of pot rotation

[R O Tiree]

Just to tidy things up and get the 2 layouts people are linking to looking somewhat similar so it's easier to see what's going on, here...

Perfectly possible, then, by changing 2 resistors, 1 electro cap, removing one resistor completely and inserting jumpers in place of another 2 to convert any stock CryBaby into a Colorsound (without the geometry "advantage" that the Colorsound has by virtue of the levers vs the rack/pinion).  Oops... EDIT and adding those 2 resistors at the output.

Sorry it's a bit big, but reducing it made it very jaggy...

[Paul Marossy]

Thanks! The schematic comparisons make it very easy to see the differences between the two circuits.

I have found that the Colorsound circuit in general has a drop in volume with the 100K/100K voltage divider on the output. So I replace the 100K series resistor with a 100K trimpot acting as a volume control, keeping the 100K resistor to ground:

                |------ OUT           
                |
              \|/
______/\/\/\/\______/\/\/\/\_____GND
           100K              100K
           TRIM

[R O Tiree]

Give me a couple of minutes...