Tight and aggressive fuzz/distortion
Lay into the notes for that deep, harmonic saturation and violin-like sustain. All your detail and articulation are preserved throughout the sustain knob's travel. Not too much bass, not too much high end--well balanced tone. Low noise floor, too!
The mods Marc did to this gets the pedal into Pink Flesh territory whilst allowing for the use of the more modern and easy to find transistors which would sound more harsh in the old Triangle or Rams Head circuits using their standard value components. Marc makes some excellent pedals for not a huge amount and unlike some builders you know he takes pride in his work, uses his ears to improve them, and the end results are always high quality. If you like the effects then try to support the builder and buy one.