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Vintage threads from the first ten years

crybaby to vox or jimmy wah mod

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1/15/1997 1:36 PM
ryan ward	crybaby to vox or jimmy wah mod i would like to modify a crybaby wah to sound more like the vox or jimmy wah. do i change the resononce cap (what location?) from .01(ufd?) to what value? thanks

1/17/1997 6:33 AM

Christian Landry

Ryan, the key to what you want is in the inductor. I have done exstensive research into this and I finally have found the right inductor. I wind my own. I have used many different cores and I have come up with some unique sounds. Ask AnalogMike, I sent him one of my prototype wah wah's. He compared it to his Clyde and said it was very close to the same sound ( and this was a Dunlop crybaby I modified ). Anyway, that is the place you want to start.
Hope that helps, Christian

1/18/1997 9:34 AM

In musical electronics, the simpler the circuit, the more you can hear the characteristics of every single part. This is particularly true in simple circuits like the standard wah circuit (or the Fuzz Face, but that is another story...).

Damn near everything inside the wah has an effect on the sound. A person who has made extensive efforts to find out how to modify the sound is Geoffrey Teese, who makes the Real McCoy wah pedals; Geoffrey can make any wah do essentially anything. His work is expensive, though, as you can imagine.

I did some work on wahs a ways back, and solved one of the mysteries. The fabled inductors in the old Vox pedals are one key to the sound. I put a real one on a spectrum analyzer and drove it from a high-purity sine source. The thing performed exactly as you would expect an inductor to until the signal level got to about 0.5v pk-pk. At that point, instead of saturating symetrically like you would expect, it clipped one side of the waveform and not the other. This produced a prominent second harmonic. The third harmonic did not come up until I was well into clipping. A current-issue Crybaby clipped at about the same place, but clipped symetrically, with NO second harmonic at any level. The third and fifth harmonics were the only significant ones.

The only good explanation for this is asymetrical core saturation, perhaps a side effect of poor core materials taking a magnetic set in one direction from the bias current that flows through the inductor in the wah circuit. Modern core materials are "better" in the EE sense, and don't take this set.

1/30/1997 11:40 PM

I wanted a wah that would faithfully and smoothly
shift the signal. That is, no volume drop at full
back and no broken glass shatter crap at full front.
I found the "Hendrix" model to have enough bass
gain (probably the amp qualities and the inductor
a higher henry value). I don't remember just what I
did but it wasn't much. I only needed to work some
top end into it now. I changed two cap values and
snipped a filter. After that the tone was even in
volume top to bottom, with alot less "wakata-wakata"
happening. Better feedback control too.
I'm no tech but I can dig through a curcuit path
and see whats happening. Other pedals require too
much modding to get enough bass volume. Not response
but volume. Good amps and the inductor value have
everything to do with it, I'm sure. It's more spendy
but start with the Hendrix wah and improve the top
end. Mine sounds killer.

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