What the Wah?

Hadn't done a wah in a while and thought I'd do project where you can build several old school wah circuits on the same board. Many of the early wahs back in the late 60s were based on the original Thomas Organ CryBaby, and as a result many of them follow the same topology with a few value changes. Here's the schematic:

A lot of the original transistors used have a BCE pinout, so I've made 2 layouts: one for BCE and one for the more common CBE pinouts. Generally speaking your just need transistors in the 300-400 hFE range, however with many circuits, different transistors offer different flavors. So as always, socket and experiment.

What the Wah? Project

Escobedo Idiot Wah

Here's a quicky designed by Tim Escobedo. It's an inductor-less wah, and you can use either a pot or an LDR to control the effect. It's small enough to fit in a 1590a if you want a fixed wah in a small package.

Resonance switch is a SPST.

Dunlop GCB-95 Cry Baby

Here's one of the most classic effects of all time, the Cry Baby wah-wah from Dunlop. The big red thing in the layout is the Fasel inductor, and there's room on the board for a pull down resistor at the input if you need it, I just didn't include it in the drawing. What else is there to say? Just build it!

ColorSound Wah-Wah

Here's the ColorSound Wah-Wah. I hadn't laid out a wah before, probably because I haven't built one myself before, and I don't use one much when I play. Anyway, the ColorSound Wah-Wah is pretty simple and sounds very good. What makes it unique is that it doesn't use an inductor like most wah circuits. This might be a good candidate to throw a buffer in front, but it's not necessary. There is a volume pot which you could omit if you want (in which case the Volume 3 pad becomes the output). You could also throw this in a 1590a if you wanted a non-treadle/fixed wah pedal. Or if you're really brave, you could mod a 1590a into a treadle pedal like Thomas Hafemann did.