This FX unit is modeled after the Foxx Tone Machine™ fuzz pedal, available from 1965-1975. Known for its long sustain.
This knob controls the distortion and the famous sustain level.
This knob controls the tone and ranges from (you guessed it!) mellow to bright!
Adjusts the overall output volume.
This switch acts like an octaver – adding harmonic distortion an octave above.