Here’s Jimi’s (second) take on the Harmonic Percolator circuit. Like the original, Jimi’s circuit uses germanium and silicon transistors, but with much more attainable components. Here’s a link to his schematic, and be sure to read his notes on changing transistors. The 47µ cap he references is located between the 2 transistors directly in the middle of the board. I’ve added polarity protection and power filtering. Pots can be mounted from the solder-side of the board using right angle PCB mount pots.
