A while ago there was a report on a German synth collector/musician in KEYBOARDS magazine in which he described this problem. He had some decoupling capacitors replaced which fixed the problem -- maybe someone could look up more accurate details?
Stephen
Gesendet: Samstag, 09. Januar 2016 um 18:18 Uhr Von: "fanwander@... [yamahacs80]" <yamahacs80@yahoogroups.com> An: yamahacs80@yahoogroups.com Betreff: Re: [yamahacs80] HIgh Pitched Whine