Discussion about the Korg PolySix synthesizer

Hello all
A few months ago I bought a Polysix from an acquaintance the day before
he moved to Toronto. I went to his house and played it and found only
two things wrong - the sub-osc switch did nothing (appeared to be stuck
at -1 octave), and the envelope sustain was stuck at 100%. He had had
the battery changed a few years previous (there was no apparent damage
to the board) and also fixed all the key contact issues the board had
when he bought it. Other than my two noted issues everything else seemed
to work just fine.
I took it home and immediately left town for a few days. When I returned
I plugged the synth in and was shocked that all it would do was make a
horrible screeching sound and the controls were about 95% unresponsive.
I took it to my tech and when he plugged it in on his bench it
immediately worked as it should. So he fixed the sub-osc and sustain
issues and I took it home again.Back at home it worked well for a few
days and in that time I decided to have a MIDI board made for it and
with a fair bit of excitement (the board sounded sweet!) I sent my money
to fine member of this group to make me the MIDI board.
Now, out of the blue, the board has started totally acting up again.
Every time I turn it on it's a totally different beast, and at least 90%
of the time it's a beast that doesn't want to make sweet sounds. Every
once it a while it'll start up and work just fine - but most often not.
I've made a video that details the Polysix's specific behaviour. I
apologize for its length (16 minutes), but as I said, every time I turn
it on it's a different animal, so I've run through a few versions of its
bad behaviour. Around the 9 minute mark it almost starts working again 
. . . sort of.
If you have any ideas what I might be dealing with here I'd love to
know.
The video is here:http://vimeo.com/29242638 <http://vimeo.com/29242638>
Cheers,James


[Non-text portions of this message have been removed]

Hi,

You have a problem with your KLM-367 board (which does all of the
patch related things). The things one can see in the video do make
sense technically; there is no need to call up esoteric spirits.

First thing is to perform the Reset adjustment (procedure is in the
file section of the list). This might cure it.

But it could easily be that there is some damage from battery leaking,
some intermittent connection on PCB traces. This would match your
description that it worked/stopped working/worked again, etc. after
moving it around.

Good luck,

Johannes


James Meagher wrote:

> Hello all
> A few months ago I bought a Polysix from an acquaintance the day before
> he moved to Toronto. I went to his house and played it and found only
> two things wrong - the sub-osc switch did nothing (appeared to be stuck
> at -1 octave), and the envelope sustain was stuck at 100%. He had had
> the battery changed a few years previous (there was no apparent damage
> to the board) and also fixed all the key contact issues the board had
> when he bought it. Other than my two noted issues everything else seemed
> to work just fine.
> I took it home and immediately left town for a few days. When I returned
> I plugged the synth in and was shocked that all it would do was make a
> horrible screeching sound and the controls were about 95% unresponsive.
> I took it to my tech and when he plugged it in on his bench it
> immediately worked as it should. So he fixed the sub-osc and sustain
> issues and I took it home again.Back at home it worked well for a few
> days and in that time I decided to have a MIDI board made for it and
> with a fair bit of excitement (the board sounded sweet!) I sent my money
> to fine member of this group to make me the MIDI board.
> Now, out of the blue, the board has started totally acting up again.
> Every time I turn it on it's a totally different beast, and at least 90%
> of the time it's a beast that doesn't want to make sweet sounds. Every
> once it a while it'll start up and work just fine - but most often not.
> I've made a video that details the Polysix's specific behaviour. I
> apologize for its length (16 minutes), but as I said, every time I turn
> it on it's a different animal, so I've run through a few versions of its
> bad behaviour. Around the 9 minute mark it almost starts working again
> . . . sort of.
> If you have any ideas what I might be dealing with here I'd love to
> know.
> The video is here:http://vimeo.com/29242638<http://vimeo.com/29242638>
> Cheers,James
>
>
> [Non-text portions of this message have been removed]
>
>
>
> ------------------------------------
>
> The original Poly6-mailinglist: http://www.acc.umu.se/~amber/Poly6/
> Yahoo! Groups Links
>
>
>
>

Hi James,

I have sent you a personal message about your issue. Check your mail!

Cheers,
Andy


On 19/09/2011 05:01, "James Meagher" <w.james.meagher@gmail.com> wrote:

>  
>  
>  
>    
> 
> Hello all
> A few months ago I bought a Polysix from an acquaintance the day before
> he moved to Toronto. I went to his house and played it and found only
> two things wrong - the sub-osc switch did nothing (appeared to be stuck
> at -1 octave), and the envelope sustain was stuck at 100%. He had had
> the battery changed a few years previous (there was no apparent damage
> to the board) and also fixed all the key contact issues the board had
> when he bought it. Other than my two noted issues everything else seemed
> to work just fine.
> I took it home and immediately left town for a few days. When I returned
> I plugged the synth in and was shocked that all it would do was make a
> horrible screeching sound and the controls were about 95% unresponsive.
> I took it to my tech and when he plugged it in on his bench it
> immediately worked as it should. So he fixed the sub-osc and sustain
> issues and I took it home again.Back at home it worked well for a few
> days and in that time I decided to have a MIDI board made for it and
> with a fair bit of excitement (the board sounded sweet!) I sent my money
> to fine member of this group to make me the MIDI board.
> Now, out of the blue, the board has started totally acting up again.
> Every time I turn it on it's a totally different beast, and at least 90%
> of the time it's a beast that doesn't want to make sweet sounds. Every
> once it a while it'll start up and work just fine - but most often not.
> I've made a video that details the Polysix's specific behaviour. I
> apologize for its length (16 minutes), but as I said, every time I turn
> it on it's a different animal, so I've run through a few versions of its
> bad behaviour. Around the 9 minute mark it almost starts working again
> . . . sort of.
> If you have any ideas what I might be dealing with here I'd love to
> know.
> The video is here:http://vimeo.com/29242638 <http://vimeo.com/29242638>
> Cheers,James
> 
> [Non-text portions of this message have been removed]
> 
>  
>    
> 
> 



[Non-text portions of this message have been removed]

Hi James,

I had a look at the schematics. Before taking out any of the boards, check this first: Maybe the power supply lines to the front panel boards are intermittent. Unplugging and plugging each connector might help, so check that first.

Do you have a DMM to check this? If so, check all power voltages on each board. Best to measure on a component like one of the IC's, not on the connectors. And then measure the resistance (with the unit turned off) for each power and ground line between the power supply and each board on the front panel. It should be low, like less than 1 ohm. Don't forget to check the ground lines, it could be the cause of all this. 

Kind regards,
Ben

On 19 sep. 2011, at 06:01, James Meagher wrote:

> Hello all
> A few months ago I bought a Polysix from an acquaintance the day before
> he moved to Toronto. I went to his house and played it and found only
> two things wrong - the sub-osc switch did nothing (appeared to be stuck
> at -1 octave), and the envelope sustain was stuck at 100%. He had had
> the battery changed a few years previous (there was no apparent damage
> to the board) and also fixed all the key contact issues the board had
> when he bought it. Other than my two noted issues everything else seemed
> to work just fine.
> I took it home and immediately left town for a few days. When I returned
> I plugged the synth in and was shocked that all it would do was make a
> horrible screeching sound and the controls were about 95% unresponsive.
> I took it to my tech and when he plugged it in on his bench it
> immediately worked as it should. So he fixed the sub-osc and sustain
> issues and I took it home again.Back at home it worked well for a few
> days and in that time I decided to have a MIDI board made for it and
> with a fair bit of excitement (the board sounded sweet!) I sent my money
> to fine member of this group to make me the MIDI board.
> Now, out of the blue, the board has started totally acting up again.
> Every time I turn it on it's a totally different beast, and at least 90%
> of the time it's a beast that doesn't want to make sweet sounds. Every
> once it a while it'll start up and work just fine - but most often not.
> I've made a video that details the Polysix's specific behaviour. I
> apologize for its length (16 minutes), but as I said, every time I turn
> it on it's a different animal, so I've run through a few versions of its
> bad behaviour. Around the 9 minute mark it almost starts working again 
> . . . sort of.
> If you have any ideas what I might be dealing with here I'd love to
> know.
> The video is here:http://vimeo.com/29242638 <http://vimeo.com/29242638>
> Cheers,James
> 
> 
> [Non-text portions of this message have been removed]
> 
> 
> 
> ------------------------------------
> 
> The original Poly6-mailinglist: http://www.acc.umu.se/~amber/Poly6/
> Yahoo! Groups Links
> 
> 
>