Search for: Your Source for DIY Pedal PCBs and NostalgiTone! › GuitarPCB Forum › Topic Tag: bass mod Viewing topic 1 (of 1 total) Topic Voices Posts Last Post Big Muff OpAmp – Bass Mod Switch? Started by: Anonymous in: GuitarPCB Build Support 2 3 3 years, 3 months ago Anonymous Viewing topic 1 (of 1 total)