Harmonic Percolator. I made the board a while back and posted it here and I'm just now able to wire it up : r/diypedals
Percolador armónico INTERFAX duplicado exacto HP-1 - Etsy España
The Curious Cult of the Harmonic Percolator | Reverb News
Zander Circuitry Cafetiere review: A brilliantly tweakable take on the InterFax Harmonic Percolator
SAF Percolator – Vaderin
Guitar Pedal X - 12 of the Best Harmonic Percolator Style Fuzzstortion Pedals - https://www.guitarpedalx.com/news/gpx-blog/12-of-the-best-harmonic- percolator-style-fuzzstortion-pedals | Facebook