MOSFET Emulation of an boosted/overdriven amp with the overall block diagram of the design taken from Nicholas Williams's DA120 amp (which in turn was based on the 70s GT120).
The idea with this pedal was to get the low-medium gain tones and texture of the amp and also achieve higher gain sounds of the amp being boosted. The total amount of gain can be controlled using the Drive and Gain controls. Although each controls gain, they function differently and affect the gain at different locations in the circuit. The pedal shines best when a little bit of amp gain is combined with the gain from the pedal. Frequency shaping is achieved using the Depth, Boost, Bass and Treble controls. These controls mirror those found on the DA120 amp where the Bass and Treble are a passive EQ (bax/james) and the Depth controls the RC low end cutoff early in the pedal. In the current revision, the Boost control functions as a mids boost. The pedal can be run off a 9V center negative supply but if desired it can run up to 18V (center negative) for additional headroom and output swing.