[sdiy] Oberheim 4-voice issues (SEM, keyboard)

Gordon JC Pearce gordonjcp at gjcp.net
Thu Jun 7 21:06:26 CEST 2012

On 07/06/12 18:28, Eric Frampton wrote:

> I've re-capped the electrolytics in the whole machine. I'm leaving all the tantalums in place, since (as best I can tell) none of them are in the power circuit. Haven't replaced any ceramics…should I go there?

I'd have left the electrolytics alone, and shot the tantalums in the 
head as a warning to all the disc ceramics ;-)

Electrolytics fail very rarely and ripping them all out and replacing 
them pretty much always does more harm than good.  Tantalum beads fail 
but tend to go shorted which makes a lot of very messy smelly greasy 
smoke, and disc ceramics go leaky.

I've replaced about half a dozen genuinely faulty electrolytics in 25 
years.  I replace a dozen leaky disc (or more usually surface mount 
block) ceramic caps a week...

Gordonjcp MM0YEQ

More information about the Synth-diy mailing list