Le forum Basses n'est pas aussi vivant et animé qu'il le mérite !

After further searching I found:
"Look at the switch that controls whether the pedal is on or off. There should be a green wire on the left, and a blue and purple wire coming out of the right. The purple wire is the hot in from the instrument. When the switch is on, the signal goes through the blue wire, and through the wah circuitry. When the switch is off, the signal passes through to the green wire, bypassing everything and going to the output.

What I did is cut the green wire from the switch, and put a 500k pot in the path as follows: I soldered a wire from the switch (where the green wire was) to the middle connection of the pot. I grounded the right connector of the pot to the screw attaching the circuit board, and attached the green wire to the left connector. Then I did a little experimenting to find out how much to turn the pot to get the right volume level. I think its around 2/3 or so.

The one possible problem I can see with this is that when using the wah circuit, there is now a path to ground through the pot. However, I think if you use a 500k pot, the resistance should be high enough not to affect the signal. I'm kind of a beginner at this stuff, so you may want a second opinion (thats what I wanted when I started this thread) but to my ear it sounds fine, and fixes the problem."