Discussion about the Korg PolySix synthesizer

Thanks a lot Andy! :-)

All voices sounds equally bad.

Here are my readings (after at least 10 min. warm-up):

TP-J7 = 14.94V OK
TP-R18 = -14.93V OK
TP-J2 = 4.97V OK
TP-J1 = -4.96V OK

IC31 (first pin (lower left) = 0)
1: -8.05V constant (no change if C8 or other key is pressed)
5:  -8.05v constant (no change if C8 or other key is pressed)
12: -8.05v constant (no change if C8 or other key is pressed)
13: -8.05v constant (no change if C8 or other key is pressed)
14: -8.05v constant (no change if C8 or other key is pressed)
15: -8.05v constant (no change if C8 or other key is pressed)
16 (upper left pin): 4.96v constant 

IC17 (upper left pin)
4.96V constant

IC18 (upper left pin)
14.91V Constant

IC19 (upper left pin)
14.91V constant


Looks like the IC31 is bad?

Cheers
Peter

--- In PolySix@yahoogroups.com, "Andrew Jury" <andy@...> wrote:
Can you confirm that 
> all of the voices appear as off key as one another? (i.e, put the P6 
> into unison mode, turn the cutoff to 10 and press C3 over and over and 
> compare each voice, etc. They all sound just as bad as one another?)
> 
> if so, check section 8 of the service manual and make sure all of the 
> voltages are within spec. Make sure the supplies to IC17/18/19 are 
> accurate. Also, make sure that demultiplexer IC31 is doing its job. 5V 
> should appear alternately on pins 13, 14, 15, 12, 1 and 5 when C8 
> pressed. Have a look around this part of the circuitry on the KLM-366 
> board and see if the voltages look correct. 
> 
> Report back your findings and we'll have another head scratch if all 
> looks well.