1. Depth: This adjusts how much the oscillator affects the signal. All the way clockwise produces a full chop, all the way counterclockwise produces no chop and the Hummingbird can be used as a simple JFET booster.
2. Mode: Three way toggle switch which selects the range of the oscillator. Mode 1 is slow, Mode 2 is mid tempo and Mode 3 is fast.
3. Rate: This adjusts the speed of the oscillator. Faster clockwise, slower counterclockwise.
4. Level: Adjusts the output volume.
5. Expression Jack: Use an expression pedal to adjust the rate with your foot! When an expression pedal is in use the Rate control is defeated. We recommend the Moog EP-2 expression pedal.