Tone Machine is a clone of Foxx Tone Machine, which was produced in 70s.
The pedal is a thick sounding fuzz with lots of gain and a footswitch that allows to add an upper octave to the sound.
The controls are:
1) Susttain – sets amount of distortion (sustain);
2) Tone – filters out high or low frequencies;
3) Volume – sets the output volume.
This circuit was used by artists ranging from ZZ Top to Adrian Belew, Parliament-Funkadelic to Peter Frampton. Its legacy has lived on as a new generation of artists (Nine Inch Nails, Beck) has discovered the fat-backed, fuzzed-out sound that pedal screams.