Few guitar pedals can rival the cult cachet of the Harmonic Percolator, a singularly ugly distortion stompbox produced in minuscule numbers in the early ’70s by Interfax, a small company based in Milwaukee, Wisconsin. And guess what? They sound ugly too, though they’re ugly in a cool and useful way.
I’ve been wanting to write about these for years, but was hindered by the fact that I don’t have access to one. No one does! Well, except the pedal’s best-known user, producer/guitarist Steve Albini. (Steve has posted several popular YouTube videos in which he sings the praises of the original and evaluates it against modern clones.)
But I revisited the idea recently when Christian Magee, who runs Tube Depot, sent me a couple of old 2N404A transistors from a stash he recently acquired. This rare PNP germanium transistor appeared in the original, along with an NPN 2N3565 (also rare, but not as ridiculously rare as the 2N404A). Yes—this pedal uses both a positive-ground germanium transistor and a negative-ground silicon transistor in the same circuit. (Another Fuzz Face/Tone Bender clone, this ain’t!)
I whipped up several variants:
- • a clone using the original parts
- • a near-clone using more readily available alternatives
- • a Harmonic Jerkulator, an all-silicon/no-diodes variation created by DIY stompbox titan Tim Escobedo
- • an experimental version with extra controls
Survey the wreckage:
Post-mortem after the jump.
