The first “instrument effect” device from Red Barn. I knew I wanted an interesting filter pedal for bass, and found several DOD FX-25 pedals used online for cheap. I sacrificed one and rehoused it in a larger enclosure with modular pots and capacitor sockets to allow testing of many circuit parameters. I was able to optimize the circuit for my preferences, and discovered a completely unexpected synthy setting!
These optimization mods and expanded controls became the Red Barn Quackspike & Quackspike Deluxe.