Recently, I ended up with a broken crybaby wah. I was already lucky enough to own a 70′s thomas organ crybaby which I love, so sacrificing this second newer crybaby for a project seemed like a fun idea. Since the crybaby chassis is extremely rugged and I like the action of the pedal, I set out to turn it into an expression pedal for my El Capistan. This article assumes that you have experience soldering and using basic tools like wire strippers, etc. Of course, always observe proper safety precautions and wear safety goggles while working on any type of electronics.

Here’s my wah on the workbench.

First, opening up this box couldn’t be easier. Just remove the 4 thumb screws from the back plate and remove the plate.

Then, unscrew the two jack nuts from the input and output jacks and also remove the single screw holding the PCB (printed circuit board) to the chassis. Unplug the cable connector, remove the PCB and set aside.

Connect your treadle pot to a standard 1/4″ TRS (tip/ring/sleeve) jack according to the schematic in tech corner #1. Desolder all wires from the pot and switch and set aside.

The “sleeve” of the jack is ground, so first connect that to the pin of the post closest to the footswitch. Then, connect a 1k resistor to the wiper (center pin) of the pot. Connect the resistor to the “tip” of the jack. Lastly, connect the pin of the pot closest to the jack to the “ring.” You’ve got an expression pedal!

Watch the youtube video for a walkthrough of the build process and an El Capistan demonstration with our completed diy project:

Happy shredding,
-terry

*All product names used in this article are trademarks of their respective owners, which are in no way associated or affiliated with Strymon or Damage Control, LLC.