Hi Nicolas, I have found the SSM2044 filter chips to be problematic. I put tiny numbered labels on the chips and then swap them around to confirm the diagnosis. With the voice LED's it is easy to tell which voice is triggered. The envelope chips can sometimes be iffy as well but switching the VCA to gate mode will give you output if this is the case. John.
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Re: Korg Polysix dead voice
2013-05-23 by John Henson