I had this cool wah pedal kicking around for a while and I recently finished restoring a Korg Delta that accepts CV input to control the filter, so I decided to make a circuit to use the foot pedal for this. I had pretty much all of the parts laying around my house and I only needed to purchase one component for the circuit. I drew the schematic up in KiCad, which is awesome and open source, and then made the circuit using perf-board and leads. I was able to salvage the original jacks which help hold the board in place over a piece of pink shipping foam for tension/insulation. I can power it with my 9V Voodoo Lab power supply.
When I found the pedal it was missing the bottom plate so I cut a new one out of these sheets of plastic I found.
One important consideration for the operation of the circuit was the Taper of the pot used to control the output voltage. The original pot is a Dunlop Hot-Potz-II which uses an "S"-taper. See this page for a good comparison of Pots. At the moment it seems usable however I am going to keep an eye out for one with a smoother taper. Ideally, it would be best to have an Audio or Log Taper for Volume and a Linear one for CV, but I am not sure of an easy way of accomplishing this.
Pretty simple circuit, see schematic and partslist for details!
Thanks for Looking!