> From: Brinkmann Music > > I disabled channels 3,4 and 5. Then was able to play 3 notes > at a time in tune. Sometimes I get a quick "portamento" when > playing the bad channels- scoops up in pitch on first playing. That sounds like problems in the sample-and-hold circuits. It's not a really hard fix, but it does involve taking the board out (which disconnects the battery and loses the memory), desoldering and replacing a bunch of parts. I'd start with the pitch-related caps (Cx00, Cx01, Cx04, Cx05), then perhaps the two 4051 switches (Zx01 and Zx02) on the affected channels. A scope would make it easier to tell exactly what's bad, so you wouldn't have to waste time changing things that aren't broken. -- Ciao, Paul D. DeRocco Paul mailto:pderocco@...
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RE: [chromapolaris] Out of Tune
2007-09-05 by Paul D. DeRocco