if you've not already, you could try switch cleaner and checking around the pot for dry solder joints. I've just resurrected a 32 year old Sequential MAX where the volume was all erratic and noise would appear randomly. Working some switch cleaner in for a while fully fixed it, like new now. No new pot needed. Also fixed the rotary encoder on a JD-990 in the same way, even though it was completely dead and I thought it was a goner.
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Re: [korgpolyex] Re: Poly800 sometimes suffers from, verry low output volume / noisey output / only sound from right(left) output
2015-01-28 by Louis Botterill