With only two knobs I refused to use anything bigger than a 1590B so I draw my own layout and made it 1590B friendly at the cost of standing resistors and two component shared holes. Based on the schematic by Ben Milner with the opamps in the LM324 reordered.
Thanks for doing this!! I've already started on it and am really excited to get it on my pedalboard. I do have a question though. For the standing diodes I wasn't sure if the white or black was the cathode end of the diodes. I had trouble seeing it on the 1n914's on the gut picture you posted of your build. Am i right in assuming that the white = cathode? It look's like that's the case on the 1n4001, but i thought i'd ask just in case.
Built it and had a headache with the diode orientation cos I didnt read the thread. The tracking on the A and E strings on my bass is a bit underwhelming but it sounds fat and fantastic. 10/10 would build again.
Several years later and I am back to report that this pedal is still my go-to octave pedal. There's still a small learning curve you've got to figure out for the tracking, but I throw this on after a BMP, with the the tone knob at about 75% on my PJ Jazz bass, and the octave down is simply :chefs-kiss:. I would think of trying out other octave pedals on my rig, but nothing else seems to make as much sense to me as this.