Converting Vox Wah into Wah/volume?

[mr_sooty]

Hey y'all,

I was wondering if you genius's had any ideas as to whether it was possible to convert my Vox V847 Wah (USA) so that it acts as a volume pedal when dis-engaged? So it becomes a 2 in 1? Wah when on, volume when off? I already have a 3PDT switch wired in.

[ashcatlt]

Wah to Volume Conversion.

I've never done it, and I have some concerns, but it's out there. Crybabys and Voxes are essentially the same circuit.

[mr_sooty]

Concerns? My main cincern is that I'm still hopeless at reading schematics.

I got this from another website:

"Wah-Volume pedal mod
Lifting the earth connection of the 4.7µF capacitor will cancel the wah effect and leave you with a volume pedal. The '70s Jen Wah-Volume pedal also switches in a 4K7 resistor and 0.22µF cap in series across the 0.01µF "sweep cap", to prevent the tone becoming thin. "

So if I could rig my 3PDT so that it lifted the ground on this resistor, and switched in these other components......well, what do you reckon?

[ashcatlt]

I think the thing that I linked to does what you're talking about, and only requires an SPST, which is exactly what you took out to fit the 3PDT. I'd use that expensive stomp switch for something more useful and go back to the original for this particular mod.

My concerns:

1) Will the thing go all the way from unity gain to negative infinity, or at least maybe
-100db so that anything that does come through is hidden in the noise floor?

The pedal is designed to prevent the pot from turning all the way from one end to the other, to avoid damage from trying to turn it too far with all the leverage you can get from the treadle. You can adjust it so that it hits one end, but then it's further from the other end.*

This might not bother you, but since I only really need a Volume pedal for swells, it's kind of big deal for me, and led me on a bit of a quest. I'll be a little upset if this mod actually accomplishes what I'm looking for.

2) Transparency. I just can't believe that all those inductors and capacitors and things aren't going to have any impact on the tone coming through the pedal.

I don't know enough about this stuff to answer either of these questions. Hopefully somebody around here can shed some light.


* In your case, it would also change the range of the wah action.

[mr_sooty]

Yeah, transparency is my biggest concern, given that the wah is the biggest tone sucker on the board, the idea of having it permanently engaged is slightly unattractive. I'm interested in exploring this mod, but I've always said that I didn't actually need a volume pedal, as my guitars conveniently came with volume knobs.

[ashcatlt]

Yeah, mine don't.

I'm (sort of) working on something involving a VCA chip for my volume pedal needs. It's a bit over my head, but I think I'm getting there.