The Electro-Harmonix Percolator is a re-elaboration of a circuit so legendary that most of its history is still guesswork. Original came out of a Milwaukee repair shop in the ’70s. Rare. Gooped. Cult status. EHX took that weird little monster and gave it modern controls without cleaning up its personality.
Three knobs, one switch. Harmonics controls input gain—from mild overdrive to full destruction. Bias adjusts the gain circuit bias, which means you can dial in everything from smooth drive to pseudo-octave nonsense to Velcro gated fuzz that sputters and dies like it’s angry at you. Balance sets your output level. The Drive/Fuzz toggle lifts or engages the clipping diodes. In Drive mode, it’s a transistor drive—raw, chewy, crunchy. In Fuzz mode, the diodes clamp down and it gets nasty.
There’s an internal trim pot under the hood for sub-octave enhancement and extra gain. You have to open the pedal to get at it, which is how it should be—tweak it once, set it, forget it.
Footswitch does latching or momentary. Press and hold for a burst of fuzz, release and it’s gone. Useful for stabbing a single ruined note into an otherwise clean passage.
$129. 9V center negative. True bypass. No digital nonsense. Just a weird, angry circuit that sounds like nothing else on the shelf.
