The classic Dan Armstrong octave effect – The Green Ringer.
Great to put in front of a fuzz or distortion pedal. The Earthquaker Devices Sunn Life pedal is basically a Green Ringer in front of a Proco Rat, with a booster.
DAN ARMSTRONG GREEN RINGER – POINT TO POINT LAYOUT
Earthquaker Devices have a version called the Tentacle, which is almost identical. For the Tentacle, just do the following:
Change Q1 and Q3 to a 2N5089
Change 1.5M resistor to 2.2M
Add 100pf capacitor from input to ground
1N4148 Diodes used
I’ve left some room on the board for power filtering if needed.