Anyone know what the Carl Martin Plexitone is based on?

[gnugear]

Or more specifically, is there a DIY clone that comes really close? I've done the BSIAB, RAT, and TS808 but the Plexitone has a nice openess to it that makes it sound really amp-like. Just wondering if its based on a tried and true circuit.

[Caferacernoc]

I think it's closest to a Marshall Guvnor with leds in the feedback loop.

[slacker]

Yeah it's sort of similar to a Marshall pedal the schematic is here http://img368.imageshack.us/i/plexitunarev3jd5.gif/