The Big Joe Tremolo is a 9v-18v, 5-knob, all analog, true bypass, vactrol based optical tremolo. The Speed and Intensity knobs set and control modulation effect between 1Hz-10Hz. Shape control varies wave form from square to triangle so you can have new wave or vintage character; Vox to Fender and anywhere in between. Tone control allows you to alter the mood and “make-up” for potential tone loss associated with the tremolo action. Output control functions as a gain trim pot control and helps to “make-up”, recover or punch up the gain structure so there is no loss of tone or volume going through the pedal, and both can be enhanced by twisting a couple of knobs. A very unique and organic sounding tremolo pedal.