Tube Distortion Pedal

The following circuit is tube distortion pedal for guitar effect. The circuit designed by Ron Black.

Circuit Notes:

• IC1 : 747 dual op-amp, other ICs may be substitued but pinout will different. You should check the datasheet
• IC2 : LM340K-12V Voltage Regulator
• All resistors are 1/2 W
• Bridge Rectifier – Full wave bridge recitifier, 50 Volts, 500 mA minimum

Overdrive/Distortion effects create “warm” and “dirty” sounds by compressing the peaks of an electric musical instrument’s sound wave, which results in a large number of added overtones. This was originally achieved by forcing too much electricity through a guitar amplifier’s valves. A slightly different method of distortion creates a “fuzzy” sound by replicating the sound of an old worn out guitar amp. This method creates noise as well as a large number of overtones. Another form of distortion is “feedback distortion” which was originally created by holding a guitar in front of a speaker. However in combination with ‘high gain’ distortion effects and a medium volume setting on a guitar amplifier, feedback can now be created simply by the removal of the damping effect of fingers touching the guitar strings.

Distortion effects are sometimes called “gain” effects, as distorted guitar sounds were first achieved by over-driving tube amplifiers. Distortion has long been integral to the sound of the electric guitar in rock and roll music, and is important to other music genres such as electric blues and jazz fusion.

Download the tube distortion pedal schematic in PDF file: