Vintage Synth Repair

Hi All!!!

I�m a synthesist from Finland and am a brand new member here. Have a lots of analog and digital gear, mainly from the 70�s and 80�s. So I have to do quite a bit of maintenance and am very willing to share my experiences to help others if possible.

Now my trusty old Micromoog from 1976 has failed and I am at loss to localise the problem. Noise, filter, and modulation work just fine, but the actual sound-producing oscillator is dead. I have heard that some people have fixed their micromoogs by replacing some op amps, but I really would like to know where to start looking. I have the service manual and have replaced a couple of bits listed as possible reasons in the troubleshooting guide. This resulted in the filter, VCA, and modulation coming back to life, but no oscillator sound.

It seems to get more complicated next, so I would very much like to hear if someone of the listees has fixed the oscilltor and what was the problem in your case...

cheers and thanks in advance,

Ami