Single-Battery Preamp 5 PUBLIC

Guitar preamp powered by a single 9-volt battery, with two Gain controls, two Fuzz circuits, and a 3-Band Fender-Style tone-stack.

Guitar preamp powered by a single 9V battery, with two Gain controls, two Fuzz circuits, and a 3-band Fender-Style tone-stack. Controls Include: Gain 1, Fuzz 1 enable switch, Fuzz 1 Drive, Fuzz 2 enable switch, Fuzz 2 Drive, Bass, Mid, Treble, Stack Sum, Gain 2, and Volume. Fuzz is provided by two identical circuits (lower portion of diagram) designed by Craig Anderton, and which use overdriven CMOS hex-inverting buffer ICs; three in series per fuzz circuit. Range above 0 dBV is from 75 Hz to 20 kHz. Maximum circuit gain is 7.6 dBV between 2.5 kHz and 4 kHz, with all controls at 50%. Maximum gain is 17 dBV with all controls at 100%. Moderate-gain circuit, suitable for 6-string guitar in standard tuning, with emphais on highs above 800 Hz. [Not good for 7/8-string guitars or bass-guitars.] For more gain, the only change that should be made is to increase the value of the Gain 2 control, up to 10M for 31 dBV, which would turn the circuit into an overdrive. Do not go greater than 10M, and do not change the Gain 1 control. Other changes can, of course, be made during breadboard testing, if desired.