Vintage MXR Phase 90 repair - I need your help! :)

[paulreedsmurf]

Okay, so I bought a '78 block logo Phase 90 a few weeks back, and I've been working on it little by little for the last few days. When I first tested it, the signal was fine when bypassed, but when turned on, the volume dropped by half and there was no phasing to be heard.

Armed with that information, I hit Google with a vengeance, and found a thread by someone with a similar problem, which had been corrected by replacing the op amps. So I did that. Worth a shot, right?

Anyway, when we finished today and started re-soldering all the wires back onto the board, we discovered a critical error... We hadn't been specific enough when we labeled where the wires were connected! Making our best guesses, we hooked it all up, plugged in, and guess what -- nothing.

So here's how you might be able to help me out (please)...

If you've got an old block logo Phase 90 like mine, would you be so kind as to open it up and snap a couple photos of the underside of the board? It's the one with six IC chips on it, not the one with three. I've looked all over Google Images, and I've only been able to find the top side. I have the schematic as well, but at this point I don't trust my schematic-reading skills too much.

Anyway, thanks a bunch for the help!

[Mooncusser]

Hope this helps friend:

http://www.tonetweakers.com/images/u...se90.s.1_g.jpg

Good luck!

[kingnimrod]

go check over at the diystompboxes.com forum - bet they can help you there.

[paulreedsmurf]

Actually, I think I struck out over there as well...

Guess I'd better just figure out that schematic, huh?

[paulreedsmurf]

@moon - thanks man, that's my board alright, but I need to see the other side to verify where the wires attach. :/ turns out this particular "block logo p90 with script board" is pretty rare.