I've definitely seen some Polysix's where VR2 seemed to do nothing and
others where it behaved as expected. I never did figure that one out.
You didn't mention VR14. This is the one most responsible for scaling in the
upper octaves. It's the one marked D#4-E4 ADJ.
You didn't mention which resistor you replaced or what values, but I assume
it is R93. When replacing the photocoupler with a Silonex or Vactrol part, I
always try putting in a precision trimmer pot here, moving VR1,2,3,14 to
their center positions and adjusting the new trimmer for best scaling before
making adjustments to the other controls.
Don B.
_____
From:
PolySix@yahoogroups.com [mailto:
PolySix@yahoogroups.com] On Behalf Of
Andrew Jury
Sent: Friday, March 11, 2011 2:26 AM
To:
PolySix@yahoogroups.comSubject: Re: [PolySix] TIME SENSITIVE REPAIR- Polysix tuning problem
question
Just a thought.... Check the operation of IC31 (s/h in at pin 3, demux at
pin 2).
You won¹t be able to fix the problem in a blind panic. Just stop, think and
take a deep breath.
Good luck,
Andy
On 11/03/2011 03:26, "Bernie GREENBERG" <
ptsaudio@sbcglobal.net<mailto:ptsaudio%40sbcglobal.net> > wrote:
>
>
>
>
>
> I am working on a Korg Polysix with the usual tuning problems. I replaced
the
> photo coupler with a VACtrol and resistor mod and still unable to tune
> keyboard. The high tuning control, VR2, seems to do nothing. I have tried
> different resistor values with the VACtrol mod and still have tuning
problems
> with the high end of the scale. TIME CRITICAL repair and going out of my
> mind!(BTW- no battery corrosion at all!)KLM367 aligned perfectly, KLM 366
> board
> is new production. PLEASE HELP!!! Thanks in advance for your time.
>
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