With all the recent talk and hype of the DigiTech Bad Monkey lately, and the sky rocketing prices of them on Reverb, a layout seemed to be in order. I used to gig with one of these and loved the Low control on it. Helped it stand out compared to other TS-style ODs. So it's worth throwing together in my book if you can't wait for prices on original units to come back to reality. This one's laid out for a 125B with top mounted jacks but you can probably squeeze it in a 1590B if you feel so inclined. Schematic over on FSB.
