Discussion about the Korg PolySix synthesizer

Hi Chris,

The p6's arp trig is expecting an 's-trig' ie. something which is shorting five volts across the tip and sleeve of the jack. The tr is sending a v-trig ie. a positive pulse trigger. You can get converters, or make one up yourself easy enough / get the fella who fixed your synth to do one. Really easy, even I managed. You might find this page helpful:

http://systemjsynthesizers.co.uk/shop/page/2

Patrick

Ah.....so I'm sending a negative trigger when I need a positive one? Or the other way around? Bugger.

Thanks for this. I'm relieved that this is something that I should be able to sort out!

Chris

The exact same discussion happened here...check it out for more info...

http://www.vintagesynth.com/forum/viewtopic.php?f=5&t=73269&hilit=polysix+arpeggiator

discusses difference between S-trig and V-trig, has links to solutions, including a simple schematic if you're a DIY guy.

Chip

Hi Frank

Issues reported seem very strange.

I can't figure out a 7th and 8th notes failure on a six cycling voice synth.

In other posts seems that VTL5C9 is the best replacement for the PC1, some overcurrent caused by VTl5C1 maybe fried some IC / resistor / polystyrene capacitor?

Regarding the leds that don't light up on boot, have you already checked the reset signal from KLM367 as described in service manual calibration notes?

On KLM367 there's VR1, you must mark with a permanent the position, if you turn it clockwise all leds on panel will light up.

Then you can turn it on other side until the leds lights off.

to be more accurate, you can jack a dummy 56Kohm to the 3 pole plug on KLM376 and follow exactly the operations shown in service manual.

Issue you describe seems more like a stuck chord mode than unison mode.

I would suspect the voice board processor or its surrounding circuitry.

Two reasons:

1. It is responsible for the assigner buttons.
2. The "7th and 8th note are silent" problem.

If I remember correctly the voice assigner actually could serve different
numbers of voices and was also used in the Mono/Poly (with 4 voices). I
also recall seeing that the polysix key assigner could serve 8 voices max.
So it looks to me that the assigner somehow switched itself into "8 voice
mode" which could be a hint that the internal programm is faulty.

On 17.11.2013 17:27, Frank Carvalho wrote:
> Hi
>
> My P6 has started having a new issue.
> The synth sounds really weird. Here are the symptoms:
> - When I boot it, it comes up with the arp on, and none of the assigner
> LEDs are lit.
> - All settings sound a bit like a unison note gone totally out of tune.
> - Freq does not change with different keys, but scaling of the filter
> seems to follow keyboard
> - Every 7th and 8th note of the keyboard is silent. The keys in between
> trigger notes (the same one all the time)
>
> I suppose this is an issue with the assigner board(?), but have no idea
> where to start. I recently replaced the optocoupler with a VTL5C1 and
> cured the keyboard scaling issue. I don't think this is related, but
> then you never know, do you?
>
> Any ideas?
>
> /Frank
>
>
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
>

The issue is related to the KLM-366 Key Assigner CPU circuitry. Probably
two of the I/O lines are dead (remember, it is an 8bit CPU).
Which keys do work and which don't?
Do the key assigner buttons (POLY/UNI/CHORD/HOLD/ARP) work?
Does the arpeggiator don anything?

Do you have access to an oscilloscope?

This surely can be fixed!

Johannes

On 18.11.2013 19:15, Frank Carvalho wrote:
>
>
> Poly/Chord/Uni do not seem to have any effect, and the LEDs don't come on.
> Hold is on when the synth is turned on, but can be turned off and on.
> Hold now lights up.
> If the keys are numbered repeatedly with 1 to 8, beginning with the
> lowest key, then it is every number 6 and 7 that is off.
> The arpeggiator sends repeated trig signals, but as the same note sounds
> every time, I cannot hear anything but the repetition. Actually the
> sound is much like a detuned unison mode.
>
> And, yes, I have an ancient Philips oscilloscope, if necessary.
>
> I certainly hope I can fix it. I love this synth.
>
> Oh, before anyone asks, I did the battery mod long ago, before any leaks
> occurred.
>
> Thanks
>
> /Frank
>
> On 11/18/2013 09:09 AM, Johannes Hausensteiner wrote:
>>
>> The issue is related to the KLM-366 Key Assigner CPU circuitry. Probably
>> two of the I/O lines are dead (remember, it is an 8bit CPU).
>> Which keys do work and which don't?
>> Do the key assigner buttons (POLY/UNI/CHORD/HOLD/ARP) work?
>> Does the arpeggiator don anything?
>>
>> Do you have access to an oscilloscope?
>>
>> This surely can be fixed!
>>
>> Johannes
>>
>
>
>

OK, so the keys that do not work are F#1, G1, D2, D#2, A#2, B2, F#3, G3,
D4, D#4, A#4, B4, F#5, and G5, correct?
When starting the arpeggiator (besides playing wrong notes) does it
light the small voice-LEDs on KLM-366?
When connecting a footswitch to the CHORD MEM footswitch jack, does the
CHORD MEM button LED work as expected (can be switched on and off by
footswitch)? Note: if you do not have a footswitch you can you a normal
phone cable and short the tip to the sleeve on the far end connector
with a paperclip or similar for a test.
And the HOLD button works?

From the noworking keys I would say the lines P16 and P17 are not
working correctly. But the buttons and the VCO control voltage should
work OK...

Try: disconnect CN12 from KLM-366 (this goes to KLM-371). Are the notes
in tune?

Johannes

On 18.11.2013 19:15, Frank Carvalho wrote:
>
>
> Poly/Chord/Uni do not seem to have any effect, and the LEDs don't come on.
> Hold is on when the synth is turned on, but can be turned off and on.
> Hold now lights up.
> If the keys are numbered repeatedly with 1 to 8, beginning with the
> lowest key, then it is every number 6 and 7 that is off.
> The arpeggiator sends repeated trig signals, but as the same note sounds
> every time, I cannot hear anything but the repetition. Actually the
> sound is much like a detuned unison mode.
>
> And, yes, I have an ancient Philips oscilloscope, if necessary.
>
> I certainly hope I can fix it. I love this synth.
>
> Oh, before anyone asks, I did the battery mod long ago, before any leaks
> occurred.
>
> Thanks
>
> /Frank
>
> On 11/18/2013 09:09 AM, Johannes Hausensteiner wrote:
>>
>> The issue is related to the KLM-366 Key Assigner CPU circuitry. Probably
>> two of the I/O lines are dead (remember, it is an 8bit CPU).
>> Which keys do work and which don't?
>> Do the key assigner buttons (POLY/UNI/CHORD/HOLD/ARP) work?
>> Does the arpeggiator don anything?
>>
>> Do you have access to an oscilloscope?
>>
>> This surely can be fixed!
>>
>> Johannes
>>
>
>
>

Also look for broken traces in the board, I've recently recaped my Trident and broke one, resulting in strange behaviour of the synth as well.

Enviado desde Yahoo Mail con Android

OK, so the keys that do not work are F#1, G1, D2, D#2, A#2, B2, F#3, G3,
D4, D#4, A#4, B4, F#5, and G5, correct?
When starting the arpeggiator (besides playing wrong notes) does it
light the small voice-LEDs on KLM-366?
When connecting a footswitch to the CHORD MEM footswitch jack, does the
CHORD MEM button LED work as expected (can be switched on and off by
footswitch)? Note: if you do not have a footswitch you can you a normal
phone cable and short the tip to the sleeve on the far end connector
with a paperclip or similar for a test.
And the HOLD button works?

From the noworking keys I would say the lines P16 and P17 are not
working correctly. But the buttons and the VCO control voltage should
work OK...

Try: disconnect CN12 from KLM-366 (this goes to KLM-371). Are the notes
in tune?

Johannes

On 18.11.2013 19:15, Frank Carvalho wrote:
>
>
> Poly/Chord/Uni do not seem to have any effect, and the LEDs don't come on.
> Hold is on when the synth is turned on, but can be turned off and on.
> Hold now lights up.
> If the keys are numbered repeatedly with 1 to 8, beginning with the
> lowest key, then it is every number 6 and 7 that is off.
> The arpeggiator sends repeated trig signals, but as the same note sounds
> every time, I cannot hear anything but the repetition. Actually the
> sound is much like a detuned unison mode.
>
> And, yes, I have an ancient Philips oscilloscope, if necessary.
>
> I certainly hope I can fix it. I love this synth.
>
> Oh, before anyone asks, I did the battery mod long ago, before any leaks
> occurred.
>
> Thanks
>
> /Frank
>
> On 11/18/2013 09:09 AM, Johannes Hausensteiner wrote:
>>
>> The issue is related to the KLM-366 Key Assigner CPU circuitry. Probably
>> two of the I/O lines are dead (remember, it is an 8bit CPU).
>> Which keys do work and which don't?
>> Do the key assigner buttons (POLY/UNI/CHORD/HOLD/ARP) work?
>> Does the arpeggiator don anything?
>>
>> Do you have access to an oscilloscope?
>>
>> This surely can be fixed!
>>
>> Johannes
>>
>
>
>

It is normal for the Polysix to be extremely out of tune for the first few seconds after it is powered on. I worked on one that seemed reasonably in tune after about 5 seconds, and another that took almost 30 seconds before it sounded decent. I believe that would be caused by the thermistors warming up, not an optocoupler problem. Do the LEDs behave any differently if the keyboard is unplugged from the 366 board?

Don B.

From: PolySix@yahoogroups.com [mailto:PolySix@yahoogroups.com] On Behalf Of Frank Carvalho
Sent: Tuesday, November 19, 2013 6:27 PM
To: PolySix@yahoogroups.com
Subject: Re: [PolySix] Weird assigner issue

No, something is wrong. It freaked while opening it up. After I unscrewed the keyboard it got better, and seemed to act normal, with all 6 Leds coming on. But suddenly it jumps back into freak mode, where only Leds 1-4 light up. Here the missing keys are F1, F1#, C2#, D2 etc.

I can get it out of freak mode by switching it off and on, but it will fall back into failure.

Btw, the optocoupler struggles initially to get the synth into tune. Could it be straining something?

(Maybe I should get a VTL5C9 instead)?

Frank

Sendt fra Samsung mobil

-------- Oprindelig meddelelse --------
Fra: Frank Carvalho <dko4342@vip.cybercity.dk>
Dato:
Til: PolySix@yahoogroups.com
Emne: Re: [PolySix] Weird assigner issue

Hi Johannes

Ok, so I turned it on to do the checks you mentioned, and everything now sounded normal again! But after a few notes, it started to get weird again, and then went back to normal. Tapping lightly on the left side of the panel reveals that I have a bad connection somewhere.
I have to open the synth again, and check for bad connections. Maybe a bad soldering, as I recently replaced the optocoupler. Fortunately, I have to say. That means that there is probably nothing fundamentally wrong with it. I'll see if I can find the culprit.

Thanks so far

Frank

On 11/18/2013 11:16 PM, Johannes Hausensteiner wrote:

OK, so the keys that do not work are F#1, G1, D2, D#2, A#2, B2, F#3, G3,
D4, D#4, A#4, B4, F#5, and G5, correct?
When starting the arpeggiator (besides playing wrong notes) does it
light the small voice-LEDs on KLM-366?
When connecting a footswitch to the CHORD MEM footswitch jack, does the
CHORD MEM button LED work as expected (can be switched on and off by
footswitch)? Note: if you do not have a footswitch you can you a normal
phone cable and short the tip to the sleeve on the far end connector
with a paperclip or similar for a test.
And the HOLD button works?

From the noworking keys I would say the lines P16 and P17 are not
working correctly. But the buttons and the VCO control voltage should
work OK...

Try: disconnect CN12 from KLM-366 (this goes to KLM-371). Are the notes
in tune?

Johannes

On 18.11.2013 19:15, Frank Carvalho wrote:
>
>
> Poly/Chord/Uni do not seem to have any effect, and the LEDs don't come on.
> Hold is on when the synth is turned on, but can be turned off and on.
> Hold now lights up.
> If the keys are numbered repeatedly with 1 to 8, beginning with the
> lowest key, then it is every number 6 and 7 that is off.
> The arpeggiator sends repeated trig signals, but as the same note sounds
> every time, I cannot hear anything but the repetition. Actually the
> sound is much like a detuned unison mode.
>
> And, yes, I have an ancient Philips oscilloscope, if necessary.
>
> I certainly hope I can fix it. I love this synth.
>
> Oh, before anyone asks, I did the battery mod long ago, before any leaks
> occurred.
>
> Thanks
>
> /Frank
>
> On 11/18/2013 09:09 AM, Johannes Hausensteiner wrote:
>>
>> The issue is related to the KLM-366 Key Assigner CPU circuitry. Probably
>> two of the I/O lines are dead (remember, it is an 8bit CPU).
>> Which keys do work and which don't?
>> Do the key assigner buttons (POLY/UNI/CHORD/HOLD/ARP) work?
>> Does the arpeggiator don anything?
>>
>> Do you have access to an oscilloscope?
>>
>> This surely can be fixed!
>>
>> Johannes
>>
>
>
>

On 20.11.2013 17:30, Frank Carvalho wrote:
>
>
> Hello
>
> I may have diagnosed and fixed the problem. I had unscrewed the keyboard
> and pulled it away from the PCB board, so that the two were not close.
> Then the P6 behaved as it should for a long time. I could play the
> (loose) keyboard, and I had the arpeggiator running for an hour.
> Everything acted normal.
> Then I put the keyboard back in place and started to play some more, and
> surely, withing a minut or two it started to behave badly again.
> This made me suspect that it is the proximity of the keyboard to the PCB
> board that really is the problem. I then put a piece of paper in between
> keyboard and PCB board, and now the P6 behaved normally again. I also
> noticed that the paper was actually pinched between keyboard and PCB
> board. So something on the keyboard is touching and possibly shorting
> something on the PCB board. Probably the new optocoupler which is right
> there under the keyboard touches a screw or something.
> So.... I have put a piece of isolation in there, and added two spacers
> to the rear keyboard fastening screws, to add a little distance, and
> this seems to have cured the problem. I guess the problem is that the
> VTL5Cxx is taller than the original optocouplers, and his brings it
> close to the keyboards. So beware when you fix the scaling problem, that
> the opto is mounted with sufficient distance.
>
> Best
>
> /frank
>
> On 11/18/2013 11:16 PM, Johannes Hausensteiner wrote:
>>
>> OK, so the keys that do not work are F#1, G1, D2, D#2, A#2, B2, F#3, G3,
>> D4, D#4, A#4, B4, F#5, and G5, correct?
>> When starting the arpeggiator (besides playing wrong notes) does it
>> light the small voice-LEDs on KLM-366?
>> When connecting a footswitch to the CHORD MEM footswitch jack, does the
>> CHORD MEM button LED work as expected (can be switched on and off by
>> footswitch)? Note: if you do not have a footswitch you can you a normal
>> phone cable and short the tip to the sleeve on the far end connector
>> with a paperclip or similar for a test.
>> And the HOLD button works?
>>
>> From the noworking keys I would say the lines P16 and P17 are not
>> working correctly. But the buttons and the VCO control voltage should
>> work OK...
>>
>> Try: disconnect CN12 from KLM-366 (this goes to KLM-371). Are the notes
>> in tune?
>>
>> Johannes
>>
>> On 18.11.2013 19:15, Frank Carvalho wrote:
>> >
>> >
>> > Poly/Chord/Uni do not seem to have any effect, and the LEDs don't
>> come on.
>> > Hold is on when the synth is turned on, but can be turned off and on.
>> > Hold now lights up.
>> > If the keys are numbered repeatedly with 1 to 8, beginning with the
>> > lowest key, then it is every number 6 and 7 that is off.
>> > The arpeggiator sends repeated trig signals, but as the same note sounds
>> > every time, I cannot hear anything but the repetition. Actually the
>> > sound is much like a detuned unison mode.
>> >
>> > And, yes, I have an ancient Philips oscilloscope, if necessary.
>> >
>> > I certainly hope I can fix it. I love this synth.
>> >
>> > Oh, before anyone asks, I did the battery mod long ago, before any leaks
>> > occurred.
>> >
>> > Thanks
>> >
>> > /Frank
>> >
>> > On 11/18/2013 09:09 AM, Johannes Hausensteiner wrote:
>> >>
>> >> The issue is related to the KLM-366 Key Assigner CPU circuitry.
>> Probably
>> >> two of the I/O lines are dead (remember, it is an 8bit CPU).
>> >> Which keys do work and which don't?
>> >> Do the key assigner buttons (POLY/UNI/CHORD/HOLD/ARP) work?
>> >> Does the arpeggiator don anything?
>> >>
>> >> Do you have access to an oscilloscope?
>> >>
>> >> This surely can be fixed!
>> >>
>> >> Johannes
>> >>
>> >
>> >
>> >
>>
>
>
>
>