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Discussion about the Korg PolySix synthesizer

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Project PolySix

Project PolySix

2015-11-13 by l3en0it@yahoo.com

Hey All,


So I have been working on a Polysix for just about a year now and I could use some help. This was a basement special and I went through quite the process to get it back up to speed, went through all the boards with 99.9% to clean it up and replaced some chips that had some compromised due to the dreaded battery acid. I bought the kiwisix board and replaced the old one out, I went through the process of tuning it and I had no luck getting it to tune it correctly. I let it sit for about 2 months after feeling pretty defeated ( I bought it for $300 and put another $550 for motherboard and power supply) and now I am ready to tackle it again. Once I turn it on I try to play a note in poly mode it doesn't work properly. It throws a high pitched whine like the freq envelope is has a slow attack. It somewhat works in unison mode, as it sounds like the voices are stacking but it doesn't have to proper tone. All voice / envelope chips work as well.. I really want to get this synth back to life if anyone can give me an idea of what to do to diagnose it I would greatly appreciate it. I would have tried more if I could find a legible circuit diagram but no cigar. I was thinking about making a video/audio recording soon as well.


Thanks,

Chris

Re: [PolySix] Project PolySix

2015-11-13 by Ben Stuyts

Hi Chris,

For a circuit diagram, try synfo.nl. It’s a great (free, but donation appreciated) resource for service manuals. (Is is Senso’s site, from vintageplanet.nl).

Ben

> On 13 Nov 2015, at 20:38, l3en0it@yahoo.com [PolySix] <PolySix@yahoogroups.com> wrote:
>
>
>
> Hey All,
>
>
>
> So I have been working on a Polysix for just about a year now and I could use some help. This was a basement special and I went through quite the process to get it back up to speed, went through all the boards with 99.9% to clean it up and replaced some chips that had some compromised due to the dreaded battery acid. I bought the kiwisix board and replaced the old one out, I went through the process of tuning it and I had no luck getting it to tune it correctly. I let it sit for about 2 months after feeling pretty defeated ( I bought it for $300 and put another $550 for motherboard and power supply) and now I am ready to tackle it again. Once I turn it on I try to play a note in poly mode it doesn't work properly. It throws a high pitched whine like the freq envelope is has a slow attack. It somewhat works in unison mode, as it sounds like the voices are stacking but it doesn't have to proper tone. All voice / envelope chips work as well.. I really want to get this synth back to life if anyone can give me an idea of what to do to diagnose it I would greatly appreciate it. I would have tried more if I could find a legible circuit diagram but no cigar. I was thinking about making a video/audio recording soon as well.
>
>
>
> Thanks,
>
> Chris
>
>
>
>

Re: [PolySix] Project PolySix

2015-11-14 by florian anwander

I use the SM from Sensos synfo.nl:
http://www.synfo.nl/servicemanuals/Korg/POLYSIX_SERVICE_MANUAL.pdf
and a camera-"scan" I did myself, from an original
http://fa.utfs.org/diy/korgpolysix/polysix_service_manual.pdf

The file from Sensos site, which is very black&white trimmed, is better
for overview. In my photography based copy, which is more gray scaled,
some details are better readable.

About your problems: I have recovered a battery damaged P6 some months
ago, it had some high frequency noise too and I found that much trouble
comes from bad grounding. Also you should whatchout that the cables from
the keyboard do not cross the audio board. Korg has bent them carefully
along the corner of the board.


And last but not least:
"It throws a high pitched whine like the freq envelope is has a slow
attack. "
I don't understand, what this sentence shall mean. I am german, so maybe
this im my fault, but to me this is not really clear English. Please try
to explain it with some other words.

Florian

Re: [PolySix] Project PolySix

2015-11-14 by moogchild synthdrome

Have you tried reseting the kiwisix?. Press LOAD & WRITE while powering on, and then wait about 10 secs. 



El vie 13 13e nov 13e 2015 a las 20:38, l3en0it@yahoo.com [PolySix]
<PolySix@yahoogroups.com> escribió:
 

Hey All,


So I have been working on a Polysix for just about a year now and I could use some help. This was a basement special and I went through quite the process to get it back up to speed, went through all the boards with 99.9% to clean it up and replaced some chips that had some compromised due to the dreaded battery acid. I bought the kiwisix board and replaced the old one out, I went through the process of tuning it and I had no luck getting it to tune it correctly. I let it sit for about 2 months after feeling pretty defeated ( I bought it for $300 and put another $550 for motherboard and power supply) and now I am ready to tackle it again. Once I turn it on I try to play a note in poly mode it doesn't work properly. It throws a high pitched whine like the freq envelope is has a slow attack. It somewhat works in unison mode, as it sounds like the voices are stacking but it doesn't have to proper tone. All voice / envelope chips work as well.. I really want to get this synth back to life if anyone can give me an idea of what to do to diagnose it I would greatly appreciate it. I would have tried more if I could find a legible circuit diagram but no cigar. I was thinking about making a video/audio recording soon as well.


Thanks,

Chris

Re: Project PolySix

2015-11-15 by l3en0it@yahoo.com

Hey,

Thanks for your responses, I tried both of those solutions but believe problem is a little deeper... when I am trying to Adjust the VCA Level I am supposed to play C3 and adjust VR9(for each voice) to get a 1v peak to peak and right now I am getting 365v @ x10 on the probe. I am wondering if I could have some bad resistors, maybe an IC Chip? 365mv is totally out of the range and the amplitude isn't getting any smaller when I adjust VR9 on any voice. Any advice?

Thanks,
Chris

Re: Project PolySix

2016-02-07 by jw_dewdney@yahoo.com

thanks Florian - that's great. The greyscale scanned one especially.