ARP Quadra Retrofit (1995)

What could be more excessive than the ARP Omni? The ARP Quadra! It's an Omni with a two-oscillator lead synth, an insane 14-stage phase shifter, and primitive programmability. And it sounds amazing. My friend Mike Novak owns one of these beasts. Years ago, it had several problems: the Poly Synth section made no sound, and the mylar touch panels had become completely inoperative. We brought it back to life by changing some blown chips and building an complete new control panel for it. Mike had already decoded the wiring of the mylar, so we implemented the same scheme with a series of pushbutton switches mounted into two pieces of aluminum channel. We drilled a couple of holes in the top and ran the wiring through them to DB25 connectors on the inside. The mating DB25's were wired to the board where the original touch panels had been hooked up. We then added P-Touch labels for the switches and LEDs, and a cooling fan on the right side. We are the "fabled" Dr. Frankensteins mentioned in this article from Sound On Sound. Here are some photos:

Here is the wiring coming into the chassis and running to the boards:

My page on ARP slider caps.