Black Cat OD-1

 Did this one quite a while ago, but wanted to redo some of the old layouts with board mounted pots. The schematic online has the topology correct but the 100nF caps are 47nF from the gut shots I've seen, so that's reflected below. Might be good to socket and experiment with.

Black Cat OD-1

This one's pretty simple, but is really versatile going from light overdrive to fuzz levels of gain. Originals use an OP275, but other dual op amps can be used (1458, 4558, TL072, etc.). It's should be a nice fit in a 1590a.