Info from Roger Mayer about the original 1985 version which this is based on:
Electronically the Mongooose uses a combination of both discrete and IC analogue design techniques. The clipping circuit primarily comes from a passive diode circuit resulting in smooth compression and harmonic overtones providing a smooth and transparent transition from clean to overload states. Chords sound very good and with the amazing amount of sustain available, feedback is possible at the lowest amplifier volume settings. These features have made the Mongoose popular in the recording studio and similar situations where feedback is desirable at low sound levels. Current users include Bono (U2) and Joe Perry (Aerosmith).
Video of the Mongoose and the Spitfire which I will be adding next:
