The MXR Tremolo’s six tremolo waveforms represent classic and iconic sources of the effect as well as new sounds concocted by the MXR design team. First, the MXR style recreates the organic sound and pulse of the much beloved M159 MXR Stereo Tremolo. Next, the Bias style takes after the lush, power-soaked compression of tremolo effects that came equipped on early 1960s tube amplifiers. The Revo style, an original innovation, turns the optical tremolo waveform backwards for more exaggerated peaks and valleys. The Opto style emulates the smooth pulsating tremolo generated by photo cells in many popular amplifiers. Inspired by an iconic outboard effect, the SQR setting produces choppy, super pronounced tremolo. Finally, the Harm style recreates the trippy, phase-like tremolo produced by certain rare vintage amplifiers.