Some pedal circuits are equals parts history and mystery, as is the inspiration for the EHX Percolator. A unique design from a Milwaukee audio repair shop in the 1970s, the original is rare, gooped, and has gained a cult-classic status. The EHX Percolator expands on this original by adding modern control to a seriously wild sounding pedal. Quick Specs - Modern take on a true legend of pedal history - Asymmetrical clipping enhancing even-order harmonics - Tones from smooth dynamic drive to ripping fuzz - HARMONICS controls gain at the input stage - BALANCE sets overall pedal output level - BIAS adjusts gain circuit bypass for achieving octave and gated sounds - DRIVE/FUZZ control lifts/engages clipping diodes - Internal trim pot for enhancing sub-octave tones and adding extra gain - Latching/Momentary footswitch action - Mechanical Relay True Bypass - 9V battery included, adaptor optional