EHX Percolator

The EHX Percolator is a modern interpretation of the rare Interfax Harmonic Percolator circuit, a cult-classic design from the 1970s known for its distinctive blend of overdrive, fuzz, and harmonic complexity. Using asymmetrical clipping that emphasizes even-order harmonics, it can produce sounds ranging from dynamic overdrive to aggressive fuzz. The Harmonics control adjusts input gain, while Bias changes the operating point of the gain stage, allowing smooth overdrive, gated fuzz, and octave-like textures. Balance sets the output level, and a Drive/Fuzz switch selects between a raw transistor-style drive sound and a more saturated fuzz voice with diode clipping engaged. An internal trim pot allows additional gain and enhanced sub-octave characteristics. The pedal also features true bypass and a footswitch that supports both standard latching operation and momentary activation for temporary bursts of the effect.