Minimoog Portamento Cap

[hopecookie]

I think my portamento cap is leaking on my mini. The portamento is faster going up than down (or vice-versa, can't remember) and when I turn the portamento up too high the pitch goes up on its own.

Can anybody tell me which cap to replace and the value. If you could also recommend source and the best type of cap thad be great too.

[Enzo]

Who says it's a cap? Could be some DC offset somewhere. Could be a lot of things. Find a schematic.

[hopecookie]

Ummm, thanks?

I think checking the cap for leakage is a good place to start. I can't really read schematics.

[Enzo]

Well, I bet we can read the schematic for you, if you have one. And without a schematic I would have no idea what cap to direct you towards.

[jrfrond]

The GLIDE (portamento) timing cap is C6 on the Contour Generator PCB, and is 1uF. However, it is tied in with two FET's (2N4303), one which controls GLIDE UP and the other GLIDE DOWN. The circuit contains a differential amp pair that uses the -10V rail as a current source, plus there are other components.

Considering how squirrely the Mini-Moog can be, I'm betting that it is something OTHER than the cap.

You DID take all of the boards out, clean ALL of the pots, switches and edge connectors with DeOxIt, perform the factory solder mods on selected edge connector flag pins, clean the key contact buss bars and springs and all interconnects FIRST, prior to reassembly and calibration, didn't you?

If you didn't do ALL of this first and run through calibration, you are most likely spinning your wheels. There is no such thing as a Mini-Moog with a single problem, and I have worked on LOTS of them.