Archive of the former Yahoo!Groups mailing list: Discussion about the Korg PolySix synthesizer

I think you need a more precise multimeter for this. Right from the reading
I'd say the scaling is slightly off and the tuning could be slightly flat
toward the top. You'll notice that the doubling usually ends with one
number lower than expected.

I've just did another test - I intentionally miscalibrated both antilog amp
and the voices. Within about 20 minutes I was able to get the tuning back
within the standard deviation chart. A better tuning might take a bit
longer.

I found the target voltages a little bit higher than your measurements.

I started out with the VR1 to VR3 and VR15 roughly centered.

Then I tried to get the highest note of the 16' setting close to 0.750 and
then worked from there.

I currently have the voltages as follows:

0.023
0.046
0.093
0.186
0.375
0.750
1.502
3.00

This results in a comparatively satisfactory tuning with no tuning VR in
its extreme position.

I initially used VR15 to get close to the 0.750 value. VR1 is only useful
for very small finetunings; I think it affects the 0.750 setting (which I
consider roughly "the middle" about +/- 2mV.

For tuning I use the following procedure:

I start with the first voice and tune 4' C6 as described in the manual.
Then I press C2 six times so I'm back at the first voice and adjust VR10 as
described in the manual. Without releasing the key I switch to 16' and
adjust according to the manual. This will usually again affect the previous
setting so I'll switch back to 4', make adjustments, switch back to 16',
make adjustments and so on. It usually takes about ten to 20 steps until
I'm close.
After this I'll usually recheck 4' C6 for that voice, readjust and repeat
the procedure.
Once the first voice hits all relevant notes with 1 cent or less deviation
I'm tuning the remaining voices.
This is now much faster because I don't have to worry about the VR15
setting for the remaining voices. So it's just top and bottom.


If I was in your place I'd probably try to turn VR15 slightly to the left
to increase all voltages a bit.