My Octave Multiplexer is another pedal than the one in the auction. But I'm too lazy right now to research what kind of models they produced. AG will know anyway
The octave (down) effect is rather ridiculous, because not audible at all. Some change in tone is there, but surely no octave(s). I never cared much for that, or the pedal itself, didn't look inside to see if there would be something to do. The fuzz is quite nice and I really like it, but it's nothing special. As is probably the case with most fuzz pedals... Also not really flexible. Unless it's turned up almost full, it sounds really weak and boring. Once a year or so I crank up the pedal and the amp to shock my neighbours on their bloody sundays, it serves at least that purpose quite well.
There are 7 RC4558, one CA3098E, one 4013, one NE5554 and one BC309 hiding under fuzz the pot. Obviously the schematic from that infamous archive that appeared some time ago or the one posted above don't match. If somebody is really interested in tracing, I can provide more infos and pictures.
And if anybody wants to see some guts of the EH Hot Tubes Overdrive, I have that lying around somewhere