This is a nice sounding overdrive for guitars. The diodes in the bias network prevent hard-saturation of the transistors.

Breadboard the circuit first, and adjust the 10k resistors to get 4.5v at each collector. If the gain is too high, try replacing the 470k/.0022uF with 2.2M/100pF. If it's too low, reduce the 470k's to 220k (except the ones near the output).

Copyright 2009 Joe Davisson. All Rights Reserved.