Discussion about the Korg PolySix synthesizer

When using a trimmer resistor (I assume it replaces R93)  with a new
opto-coupler, it is best to set all other VRs (VR1,2,3) to mid-point, set
the trimmer where you get the best scaling, and start from there. VR4 and 5
are not associated with tuning.

Also, try adjusting VR14, marked D#4-E4. This adjusts the scaling for the
upper end of the keyboard.

Don B.

 

  _____  

From: PolySix@yahoogroups.com [mailto:PolySix@yahoogroups.com] On Behalf Of
genetik
Sent: Friday, March 30, 2012 9:53 PM
To: PolySix@yahoogroups.com
Subject: [PolySix] Tuning Issue--the opto is replaced

 

  

Hi, I just picked up a polysix with the battery replaced and board cleaned
up. Everything is functional. The only issue is tuning. I followed the
service manual and cannot get the synth in tune. It seems like the range of
the VRs for the oscillators. If the high note C is in tune, the VR maxed out
is still not C. And visa versa. After tuning high C at C6 with 4', C2 cannot
be set to 0 cents either. It is more like A or A#. The scaling seems off.
The opto is replaced with a VTL5C3 that tests correctly and has a
fine-tuning resistor that i set at 1k2. Only that that seems weird is that
when I put the test lead of my multimeter of pin 6 of the connector for
keyboard tracking it shows -5V. VR5 and VR2 seem to do nothing. Help!





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