Volume: Sets the overall output volume.
Gain: Sets the amount of Distortion in both Fuzz and Overdrive stages.
Drive Tone: Sets the cutoff frequency for the low-pass filter on the output of the Overdrive.
Fuzz Shape: Selects between 6 different analog filters on the output of the Fuzz
Series / Parallel: Selects between Overdrive routed before Fuzz or Parallel routing.