Discussion about the Korg PolySix synthesizer

I managed to cobble together a working Polysix from 2 dead units and a
rebuilt 367 from Old Crow. The oscillators sound pretty in tune, so I
left them alone.

I'm a big fan of self-oscillating resonant filters, so I fiddled
around with the frequency filter VRs to get all the filters tuned to
the same note. Then I screwed around with the KBD TRACK (VR5) and KBD
TRACK OFFSET (VR13) on the 367, knowing that if I sent everything
screwy, I could refer back to the calibration manual I downloaded from
Old Crow's site.

But when I went to the manual, it says to test CN05-06 (which I take
to mean Connector 5, Pin 6) and make sure you get +1.8V. When I test
that pin, I get anywhere from -5 to +5 volts depending on the setting
of Keyboard Track pot on the front panel. The manual doesn't mention
KBD OFFSET.

So my KBD TRACK, KBD OFFSET and FILTER F0 and OFFSET pots are probably
set way out of factory standard and I have no way to get home.

Thus my questions -

1. Is the calibration manual off the Old Crow site the right manual to
use for a 366B? If not, where can I get the right one?

2. If the calibration manual I have is the right one, what am I doing
wrong?

3. Can one get tuned filters over the entire keyboard range, or is
that practically impossible? The best I get was 1 - 2 octaves in tune.
It sounds ok, but it could be better.

4. What is the difference between VR7 (filter offset) and VR8 (filter f0)?

My overriding goal is to get the unit back to factory standard. Any
help towards that end would be much appreciated.

Thanks
Lionel Cassin

> But when I went to the manual, it says to test CN05-06 (which I take
> to mean Connector 5, Pin 6) and make sure you get +1.8V. When I test

This means that you have to adjust the KBD Track control panel knob
so that you read 1.8V at the connector and then make any trimpot
adjustments with this setting.
The adjustment procedure is part of the official Korg Polysix service
manual; there should be no error in it. The VCO alignment section
can be done faster and more accurate (by tuning the voices to each other
not each voice independently), but the filter section is OK.
... But the filter CF is not that accurate to regularily "tune" them
and play them as additional oscillators. You will end up in a mistuned
or "honkey tonkey" sound.

The offset pot (VR7) sets the audio signal offset (= eliminating DC
component in audio), whereas "Filter F0" (VR8) sets the center frequency
of the VCF.

Good luck!

Johannes



lionelcassin wrote:

> I managed to cobble together a working Polysix from 2 dead units and a
> rebuilt 367 from Old Crow. The oscillators sound pretty in tune, so I
> left them alone.
>
> I'm a big fan of self-oscillating resonant filters, so I fiddled
> around with the frequency filter VRs to get all the filters tuned to
> the same note. Then I screwed around with the KBD TRACK (VR5) and KBD
> TRACK OFFSET (VR13) on the 367, knowing that if I sent everything
> screwy, I could refer back to the calibration manual I downloaded from
> Old Crow's site.
>
> But when I went to the manual, it says to test CN05-06 (which I take
> to mean Connector 5, Pin 6) and make sure you get +1.8V. When I test
> that pin, I get anywhere from -5 to +5 volts depending on the setting
> of Keyboard Track pot on the front panel. The manual doesn't mention
> KBD OFFSET.
>
> So my KBD TRACK, KBD OFFSET and FILTER F0 and OFFSET pots are probably
> set way out of factory standard and I have no way to get home.
>
> Thus my questions -
>
> 1. Is the calibration manual off the Old Crow site the right manual to
> use for a 366B? If not, where can I get the right one?
>
> 2. If the calibration manual I have is the right one, what am I doing
> wrong?
>
> 3. Can one get tuned filters over the entire keyboard range, or is
> that practically impossible? The best I get was 1 - 2 octaves in tune.
> It sounds ok, but it could be better.
>
> 4. What is the difference between VR7 (filter offset) and VR8 (filter f0)?
>
> My overriding goal is to get the unit back to factory standard. Any
> help towards that end would be much appreciated.
>
> Thanks
> Lionel Cassin
>
>
>
>
>
>
>
> PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> Yahoo! Groups Links
>
>
>
>
>
>
>

Thanks for the quick reply.

Ok, so I adjust the KBD Track control panel knob so that I get +1.8V
on CN05-06 and then adjust the KBD Track trimpot to get as close to an
equal tempered keyboard as I can?

LC

--- In PolySix@yahoogroups.com, Johannes Hausensteiner <johau@...> wrote:
>
> > But when I went to the manual, it says to test CN05-06 (which I take
> > to mean Connector 5, Pin 6) and make sure you get +1.8V. When I test
> This means that you have to adjust the KBD Track control panel knob
> so that you read 1.8V at the connector and then make any trimpot
> adjustments with this setting.
> The adjustment procedure is part of the official Korg Polysix service
> manual; there should be no error in it. The VCO alignment section
> can be done faster and more accurate (by tuning the voices to each other
> not each voice independently), but the filter section is OK.
> ... But the filter CF is not that accurate to regularily "tune" them
> and play them as additional oscillators. You will end up in a mistuned
> or "honkey tonkey" sound.
>
> The offset pot (VR7) sets the audio signal offset (= eliminating DC
> component in audio), whereas "Filter F0" (VR8) sets the center frequency
> of the VCF.
>
> Good luck!
>
> Johannes
>
>
>
> lionelcassin wrote:
> > I managed to cobble together a working Polysix from 2 dead units and a
> > rebuilt 367 from Old Crow. The oscillators sound pretty in tune, so I
> > left them alone.
> >
> > I'm a big fan of self-oscillating resonant filters, so I fiddled
> > around with the frequency filter VRs to get all the filters tuned to
> > the same note. Then I screwed around with the KBD TRACK (VR5) and KBD
> > TRACK OFFSET (VR13) on the 367, knowing that if I sent everything
> > screwy, I could refer back to the calibration manual I downloaded from
> > Old Crow's site.
> >
> > But when I went to the manual, it says to test CN05-06 (which I take
> > to mean Connector 5, Pin 6) and make sure you get +1.8V. When I test
> > that pin, I get anywhere from -5 to +5 volts depending on the setting
> > of Keyboard Track pot on the front panel. The manual doesn't mention
> > KBD OFFSET.
> >
> > So my KBD TRACK, KBD OFFSET and FILTER F0 and OFFSET pots are probably
> > set way out of factory standard and I have no way to get home.
> >
> > Thus my questions -
> >
> > 1. Is the calibration manual off the Old Crow site the right manual to
> > use for a 366B? If not, where can I get the right one?
> >
> > 2. If the calibration manual I have is the right one, what am I doing
> > wrong?
> >
> > 3. Can one get tuned filters over the entire keyboard range, or is
> > that practically impossible? The best I get was 1 - 2 octaves in tune.
> > It sounds ok, but it could be better.
> >
> > 4. What is the difference between VR7 (filter offset) and VR8
(filter f0)?
> >
> > My overriding goal is to get the unit back to factory standard. Any
> > help towards that end would be much appreciated.
> >
> > Thanks
> > Lionel Cassin
> >
> >
> >
> >
> >
> >
> >
> > PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >
>

Yes!

lionelcassin wrote:

> Thanks for the quick reply.
>
> Ok, so I adjust the KBD Track control panel knob so that I get +1.8V
> on CN05-06 and then adjust the KBD Track trimpot to get as close to an
> equal tempered keyboard as I can?
>
> LC
>
> --- In PolySix@yahoogroups.com, Johannes Hausensteiner <johau@...> wrote:
>
>> > But when I went to the manual, it says to test CN05-06 (which I take
>> > to mean Connector 5, Pin 6) and make sure you get +1.8V. When I test
>>This means that you have to adjust the KBD Track control panel knob
>>so that you read 1.8V at the connector and then make any trimpot
>>adjustments with this setting.
>>The adjustment procedure is part of the official Korg Polysix service
>>manual; there should be no error in it. The VCO alignment section
>>can be done faster and more accurate (by tuning the voices to each other
>>not each voice independently), but the filter section is OK.
>>... But the filter CF is not that accurate to regularily "tune" them
>>and play them as additional oscillators. You will end up in a mistuned
>>or "honkey tonkey" sound.
>>
>>The offset pot (VR7) sets the audio signal offset (= eliminating DC
>>component in audio), whereas "Filter F0" (VR8) sets the center frequency
>>of the VCF.
>>
>>Good luck!
>>
>>Johannes
>>
>>
>>
>>lionelcassin wrote:
>>
>>>I managed to cobble together a working Polysix from 2 dead units and a
>>>rebuilt 367 from Old Crow. The oscillators sound pretty in tune, so I
>>>left them alone.
>>>
>>>I'm a big fan of self-oscillating resonant filters, so I fiddled
>>>around with the frequency filter VRs to get all the filters tuned to
>>>the same note. Then I screwed around with the KBD TRACK (VR5) and KBD
>>>TRACK OFFSET (VR13) on the 367, knowing that if I sent everything
>>>screwy, I could refer back to the calibration manual I downloaded from
>>>Old Crow's site.
>>>
>>>But when I went to the manual, it says to test CN05-06 (which I take
>>>to mean Connector 5, Pin 6) and make sure you get +1.8V. When I test
>>>that pin, I get anywhere from -5 to +5 volts depending on the setting
>>>of Keyboard Track pot on the front panel. The manual doesn't mention
>>>KBD OFFSET.
>>>
>>>So my KBD TRACK, KBD OFFSET and FILTER F0 and OFFSET pots are probably
>>>set way out of factory standard and I have no way to get home.
>>>
>>>Thus my questions -
>>>
>>>1. Is the calibration manual off the Old Crow site the right manual to
>>>use for a 366B? If not, where can I get the right one?
>>>
>>>2. If the calibration manual I have is the right one, what am I doing
>>>wrong?
>>>
>>>3. Can one get tuned filters over the entire keyboard range, or is
>>>that practically impossible? The best I get was 1 - 2 octaves in tune.
>>>It sounds ok, but it could be better.
>>>
>>>4. What is the difference between VR7 (filter offset) and VR8
>
> (filter f0)?
>
>>>My overriding goal is to get the unit back to factory standard. Any
>>>help towards that end would be much appreciated.
>>>
>>>Thanks
>>>Lionel Cassin
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
>>>Yahoo! Groups Links
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>
>
>
>
>
>
> PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> Yahoo! Groups Links
>
>
>
>
>
>
>

I tried to contact crow a few times as for buyin a naked KLM-367A
board but got no answer.... is he still making those ?

--- In PolySix@yahoogroups.com, "lionelcassin" <lionel@...> wrote:
>
> I managed to cobble together a working Polysix from 2 dead units
and a
> rebuilt 367 from Old Crow. The oscillators sound pretty in tune, so
I
> left them alone.
>
> I'm a big fan of self-oscillating resonant filters, so I fiddled
> around with the frequency filter VRs to get all the filters tuned to
> the same note. Then I screwed around with the KBD TRACK (VR5) and
KBD
> TRACK OFFSET (VR13) on the 367, knowing that if I sent everything
> screwy, I could refer back to the calibration manual I downloaded
from
> Old Crow's site.
>
> But when I went to the manual, it says to test CN05-06 (which I take
> to mean Connector 5, Pin 6) and make sure you get +1.8V. When I test
> that pin, I get anywhere from -5 to +5 volts depending on the
setting
> of Keyboard Track pot on the front panel. The manual doesn't mention
> KBD OFFSET.
>
> So my KBD TRACK, KBD OFFSET and FILTER F0 and OFFSET pots are
probably
> set way out of factory standard and I have no way to get home.
>
> Thus my questions -
>
> 1. Is the calibration manual off the Old Crow site the right manual
to
> use for a 366B? If not, where can I get the right one?
>
> 2. If the calibration manual I have is the right one, what am I
doing
> wrong?
>
> 3. Can one get tuned filters over the entire keyboard range, or is
> that practically impossible? The best I get was 1 - 2 octaves in
tune.
> It sounds ok, but it could be better.
>
> 4. What is the difference between VR7 (filter offset) and VR8
(filter f0)?
>
> My overriding goal is to get the unit back to factory standard. Any
> help towards that end would be much appreciated.
>
> Thanks
> Lionel Cassin
>

I don't know if he's still in the business. He rebuilt mine more than
a year ago.

The deal was that you must send him a board and then he rebuilds it. I
don't believe he builds them from scratch.

Tx
LC

--- In PolySix@yahoogroups.com, "gil_we" <gil_we@...> wrote:
>
> I tried to contact crow a few times as for buyin a naked KLM-367A
> board but got no answer.... is he still making those ?
>
>
> --- In PolySix@yahoogroups.com, "lionelcassin" <lionel@> wrote:
> >
> > I managed to cobble together a working Polysix from 2 dead units
> and a
> > rebuilt 367 from Old Crow. The oscillators sound pretty in tune, so
> I
> > left them alone.
> >
> > I'm a big fan of self-oscillating resonant filters, so I fiddled
> > around with the frequency filter VRs to get all the filters tuned to
> > the same note. Then I screwed around with the KBD TRACK (VR5) and
> KBD
> > TRACK OFFSET (VR13) on the 367, knowing that if I sent everything
> > screwy, I could refer back to the calibration manual I downloaded
> from
> > Old Crow's site.
> >
> > But when I went to the manual, it says to test CN05-06 (which I take
> > to mean Connector 5, Pin 6) and make sure you get +1.8V. When I test
> > that pin, I get anywhere from -5 to +5 volts depending on the
> setting
> > of Keyboard Track pot on the front panel. The manual doesn't mention
> > KBD OFFSET.
> >
> > So my KBD TRACK, KBD OFFSET and FILTER F0 and OFFSET pots are
> probably
> > set way out of factory standard and I have no way to get home.
> >
> > Thus my questions -
> >
> > 1. Is the calibration manual off the Old Crow site the right manual
> to
> > use for a 366B? If not, where can I get the right one?
> >
> > 2. If the calibration manual I have is the right one, what am I
> doing
> > wrong?
> >
> > 3. Can one get tuned filters over the entire keyboard range, or is
> > that practically impossible? The best I get was 1 - 2 octaves in
> tune.
> > It sounds ok, but it could be better.
> >
> > 4. What is the difference between VR7 (filter offset) and VR8
> (filter f0)?
> >
> > My overriding goal is to get the unit back to factory standard. Any
> > help towards that end would be much appreciated.
> >
> > Thanks
> > Lionel Cassin
> >
>