The Harmonic Tremor Tremolo is one of the hidden gems in the ModTone line. Designed to emulate the lush tremolo found on old tube amps, the Harmonic Tremor can go from a subtle wave to an all out pulsating effect without signal drop or degrading noise. The Wave knob can take you from that amp-like tremolo to an extreme square wave tremolo with the twist of your hand. Dial in the pedal using the flashing LED light that responds to the rate of the pulse. The ModTone Harmonic Tremor Tremolo has all the features to be the perfect tremolo for you.