The Stage 2 (2nd speed setting) can be selected by holding down the pedal. Rate controls the speed/rate of the LFO wave that controls the effect Rate (speed for stage 2) Depth controls the depth/amplitude of the modulation (the size of the range in which the effect sweeps). Feedback sets the amount of effected signal fed back into the effect (for a stronger effect) Manual sets the position of the effect when the LFO is in the center position or controls the effect when the LFO is switched off
