This is the note from the files section:
From a user (the solution refers to the problem of not being able to get correct scaling of the Polysix keyboard):
I wanted to let you know that I've finally managed to repair my
Precious (Polysix). It was indeed the opto resistor, the PC-1, that
was faulty. It was suggested to me that I replace the old mysterious
PC-1 component with a VTL5C3 and change R93 from 4k7 to 1k2 (to get
the VTL5C3 working properly). I did and then the synth was as good
as new!
Appearently, the PC-1 is what stabilizes the expo-converter circuit.
If it's broken, the circuit can't manage to keep the synth in tune
as the voltages vary (which is especially noticeable during the time
the machine is warming up).
Thanks for the help!
On Tue, Dec 16, 2014 at 5:27 AM, pasitive@gmail.com [PolySix] <PolySix@yahoogroups.com> wrote:Hi,
I've got Korg Polysix here, with clone KLM367.
There's something wrong with tuning. C-keys are something like F and octave is couple semitones shorter than it should be. It's impossible to get it tuned right. I've been following several calibration instructions without any success.
VR2 has no effect at all.
Is it photocoupler? IC18 pin 7 gives +12v. As I understood it should give something like -2v - -5v, but this one gives something else..