The Saturator effect adds either Tube or Tape type distortion, depending on the Tube and Tape buttons. The Drive knob controls the amount of distortion. The output level is approximately equal to the input level.
Drive controls the signal level that's fed to the virtual preamp's input. The VU meter shows the average value. At 0 dB total harmonic distortion is approx. 2%.
Drive controls the virtual recording level. The VU meter shows the average value of the recording level. At 0 dB VU total harmonic distortion is approx. 1%.
LF Peak controls low frequency peaks ("bumps"). Flutter controls the amount of wow & flutter.