Rhythm & Detonation

Pimp My Wah

This is a Dunlop gcb-95 that I modded for Jeremy Norman. This little guy pretty much got the full treatment.

Wah pedals are notorious tone suckers because they use a crappy half-bypass setup, such that your signal is still loaded down by the pedal, even when the pedal is off. So I first modified the wah for true bypass. Now when the effect is turned off, the signal passes straight through.

While changing the switch to accommodate true bypass, I added a blue LED. I was terrified about trying to drill a hole in this pedal because it's HEAVY cast steel, and I wasn't sure what it'd do to my drill bits. I carefully positioned the drill bit in place and pushed down to seat the drill bit, and it popped right through the case without even turning on the drill! I ran the drill through to clean it and installed a waterclear, super-bright blue LED. One of my biggest pet peeves about wah pedals is that they don't have an LED to indicate whether the effect is on, so this solves that problem.

The second major upgrade was to swap the cheap inductor with a vintage re-issue FASEL inductor. Dunlop owns the FASEL factory in Italy and the rights to distribute them. These are the inductors used in the original Vox wahs. It's a worthy upgrade to replace the stock inductor, and it helps capture that voice and growl of classic wahs.

I then heavily modified the circuit, including increasing the gain of the wah and sharpening the "Q" on the vocal mod, which makes the wah sound more like a "WAH" then a "WOH". I also lowered the range of frequencies in which the wah operates, helping with the bass response. I changed the .01uF range cap to a .022uF range, which happens to be the difference between the stock wah and the Jimi Hendrix wah. I also raised the midrange response to smooth out the transition from low to high on the wah.

For more info on modding wahs, check out this great resource: Stinkfoot