[sdiy] PolyMoog

[Mike Granger]

Hey Gene,

Hope you don't mind my writing you, but you are the only person I know 
of that has a PolyMoog Synthesizer.

I was repairing a 24 channel MCI mixing board for a local recording 
studio last week, and the owner asked me during a break if  I was 
interested in looking at some old equipment in the upstairs equipment 
room. I went up and to my surprise among the junk was a beautiful (but 
dusty) Poly Moog!!! There was even the pedal system there with it. The 
guy told me he had bought it in 1978 to use in making jingles and 
commercials, and that it used to be his favorite keyboard while it was 
still working. He said it quit on him one day, adn he had never found 
anyone willing to work on it for him.

I told him that I knew what it was, and wouldn't mind trying to repair 
it for him. He said that he didn't have much use for it these days even 
if it was in working condition, and if I was interested in it, maybe we 
could work out a trade for my repair work on the console.

I figured I'd never have another chance to get one in such nice cosmetic 
shape, so when the console repairs were done, I told him I'd trade him 
even for the Moog. He was tickled to death, and I walked away with 
something I've dreamed of having since I first heard Keith Emerson play 
the prototype in the '70s.

Got the M oog home, and took my first look inside one of these beautiful 
instruments. It wouldn't power up at all. Checked the line fuses, and 
they were fine. Looked at the outputs of the power supply and saw 
nothing there at all. I pulled the supply out for a closer look, and 
noticed that all the output connector pins had hairline cracks where 
they used to be soldered to the PC board. I fired up my iron and renewed 
the connections, put the supply back in and held my breath while I 
turned on the power switch. I had lights on the panel, and the mode 
display lit up with a 9. Quick check of the output with my headphones 
lett me know I hadn't completely lucked out. There was no +15 volt 
output. I checked the positive supply to ground resistance and saw a 
dead short. Started pulling connectors until I found out that the short 
was on the upper left hand board (the one with the 726's on it), and 
went through a check of all the plug in chips, adn finally started 
disconnecting  bypass tantalums until I found the culprit!

The Poly plays now, but I don't know what the functions are supposed to 
do. There is no sample and hold function, something seems to be wrong 
with the VCLPF controls, a couple of keys up and down the Keyboard sound 
different than the rest (polycom boards??), and I have a lot of cleaning 
and small repairs to do, but I have a playable PolyMoog!!!

Do you know where I can get schematics and operations/ service manuals 
for it?

Any help getting me pointed in the right direction is greatly appreciated.

Merry Christmas, Gene. I've got the best present I could hope for!

Mike Granger