I recently bought a used Boss GT-3 and was wondering how I could
switch the Wah on and off without changing patches. The GT-3
expression pedal doesn't have that switch which gets activated when
you stomp on the pedal (like regular wah-pedals or the new GT6). So,
I taped a small eraser (the rubber stuff for erasing pencil marks)
under the toe part of the expression pedal, so that it doesn't go all
the way down unless you step on it hard. Then, on the pedal assign
screen of the GT3 I set the expression pedal to control the "pedal"
parameter of the Wah, and set assign1 to toggle Wah on and off only
when the expression pedal was above 100. I also set the expression
pedal values to 0-90 for the wah pedal control so it gets to the full
range. This thing works perfectly! I forget that it's such a cheap
mod when i'm jamming in the studio.
This would probably work with any expression pedal and an effects
processor that lets you assign pedal actions in detail. Check it out!
I just had to share it with the world 'cuz it's so cheap ;)
Daniel