Fuzz Box (Distorion Pedal) Electric Guitar Effect

The two transistors amplifies the input signal from electric guitar. The two  silicon diodes (any small signal type can be used)  clips the amplified signal to produce a  highly distorted output, after filtering the high frequency component using a 500 pF capacitor. The amount of the fuzz is adjustable from maximum fuzz to pure clean (normal playing).

This guitar effect is unique in the way it adjust the distortion level, it uses a potentiometer to adjust the proportion between the bypassed and the processed signal. You can see at one side the signal from electric guitar is fed directly to the transistor amplifier input while the bypassing is minimized by 1M Ohm path in the potentiometer. At other side pot position, the signal coming from the guitar is fed directly to the output (bypassed), where the connection to the input is attenuated by 1M Ohm path inside the potentiometer. [Circuit’s schematic diagram source: seekic.com]