Wah/Volume question..

[hammerheadmusicman]

So a friend has asked me to build him a good wah into an old shell he has.

He asked me, if it would be possible to have the wah pedal as a volume pedal when the circuit is not engaged.

I'm trying to wrap my head around it.

We built a passive volume pedal out of an old wah, just using a pot.

Would it be possible to switch to that?

Or possibly, a small breakout box with another Footswitch in, 4PDT maybe. I have one lying around.

George

[brejna]

Since passive volume pedals have their disadvantage, maybe you could put one more circuit in it like this one http://www.tonepad.com/getFile.asp?id=2
and than try to use same pot to control volume and wah like you sad. For selection 4PDT could  be enough I think
Brane

[brejna]

Wiring something like this? 

[brejna]

... but I think that tonepad volume can't be used in this application

[joegagan]

for a volume pedal, the big problem is the physical limitation of the standard rack gear/round gear setup.
pots don't go full silent until they are riding right into the internal stop. this puts a strain on the pot and is very hard to dial in perfectly. also, if the same pot is used for wah , the adjustment for optimal wah may or may not be full heel down. see note 'a' below.
passive volume pedals are 250k, 500k, 1 meg, actually for most setups 500k and 1 meg are optimal. this may or may not work well with your wah.

most people expect a volume pedal to go full silent because the ernie ball and morley pedals do that. the ernie ball does not strain the pot because the string takes up a tiny bit of the strain.

some notes:
a. you could use two pots on one gear facing each other as in the old crybaby stereo fuzz wah, this way each pot can be individually tuned for optimum setting. difficult but possible. again, the volume pedal side's internal stop issue remains.
*you could rig up some sort of switch to ground out the volume pot at near-silent, see video below.

b. if you make the volume pedal active and are trying to use the same pot for wah & vol, you can set it up for a wider ( lower value) range of pots. you can also tune the circ to sound or sweep differently.

c. the maestro boomerang is the best i have heard of the old style inductor wah/ volume combos. when set up right and the proper pot is used the volume function has a nice sweep and a very mild boost at toe down. BUt, it does not go full silent on heel down.

d. pot taper. people who use volume pedals regularly are usually VERY picky about taper. it is unlikely that a pot that has a good taper for wah will be a pleasing taper for volume.

e. a dual gang pot solves the dual value problem, but suffers the 'not silent at heel down' problem in most cases.

f. the one pot solution is tricky, the two pots facing each other solution is a mechanical challenge.

g. you could rig up an opto type circuit for the volume portion. part morley, part crybaby.

is it any wonder that there doesn't seem to be a really satisfying inductor type wah-volume on the market?

switch for grounding volume pedal circ out at heel down - primitive version:

boomerang , demonstrating the volume pedal lack of tonesucking.

[hammerheadmusicman]

The thought of having two pots on the same gear was a thought that had crossed my mind.

I'll watch those vids and investigate some more.

I did mention the problem with the wah pot taper, but he looked at me as If I was talking a foreign language, so I have up!

[joegagan]

that brings up an advantage for the LED/ LDR setup. you could keep trimming the shutter piece to make whatever taper you want. make the shutter piece screw in and out with a simple flat bracket so you can swap them quickly. make the shutter out of thin black plastic , like from office supply file dividers etc.

[hammerheadmusicman]

For the volume part right, that would probably be the way option. I had been thinking that too, after seeing an article recently on an LED/LDR based wah

[jkokura]

The Boomerang is what I thought of instantly. I will say however, that it's not perfect. Mine doesn't quite have a full throw from silent to full volume.

Jacob

[hammerheadmusicman]

The guy is really fussy, which is why I didn't commit to being able to say 'Yeah, I can do that'.

I'm thinking an led/LDR might be the way to go...