Colorsound Overdriver

For all you fans of the 2 Transistor English Fuzz, this is a nice variation/evolution on that circuit. TR1 now sports an emitter resistor plus feedback from TR2's collector. Note that the "GAIN" control has migrated from TR2's emitter to TR1's emitter.

The filter network is much more sophisticated than the typical tone controls placed in these early guitar pedals. The filter works via shunt negative feedback through the 25µF capacitor attached to TR3's collector.