The following distortion pedal schematic is for the original ProCo Rat. This circuit is very close to the BOSS DS-1 circuit. This is a very popular design for modding, customizing or building your own distortion pedal. Some of the popular mods include resistor mods for reducing gain and thickening the bass of the sound, adding additional toggle switches, removing some of the diodes for a volume boost, replacing the op-amp, or a combination of all mods. If you have a great mod for this distortion pedal, we would love to hear from you so drop us a comment!
This schematic for the Rat was taken from the great people over at the Free Information Society here: ProCo Rat schematic