Discussion about the Korg PolySix synthesizer

I know this sounds stupid, but how can i tell if the PWM is working?
If it is not, where do I start looking to fix it?
Thanks!

First thing to do is set VCO to PW and move the width knob from 0 to 10
and back to 0 and listen to see if it changes accordingly. Then set it to
10 and change the VCO mode to PWM and move the PWM speed knob from 0 to 10
slowly and note if the cyclic modulation is audible.

If nothing is working then I would imagine either IC20 (LM13600) needs
replaced, or the analog switch section IC1C died and IC1 needs replaced,
or perhaps the control voltages off deMUX IC19 aren't getting there and
IC19, IC12 or IC13 is to blame (least likely though).

Use my schematic as it is much easier to read than the old service
manual copy. PWM circuit is on the far right, about 2/3 of the way down.
It is marked "PWM MG":

http://www.oldcrows.net/~oldcrow/synth/korg/polysix/crowlm367/klm367a_eagle_schem.gif


Hope this helps,

Crow
/**/

On Wed, 31 Dec 2003, ciscomanvann wrote:

> I know this sounds stupid, but how can i tell if the PWM is working?
> If it is not, where do I start looking to fix it?
> Thanks!

Nothing happens. It plays, but the width or pwm does not change. I
have a multimeter, how do i check this stuff out? I dont know a whole
lot about ICs.

--- In PolySix@yahoogroups.com, The Old Crow <oldcrow@o...> wrote:
>
> First thing to do is set VCO to PW and move the width knob from 0
to 10
> and back to 0 and listen to see if it changes accordingly. Then
set it to
> 10 and change the VCO mode to PWM and move the PWM speed knob from
0 to 10
> slowly and note if the cyclic modulation is audible.
>
> If nothing is working then I would imagine either IC20 (LM13600)
needs
> replaced, or the analog switch section IC1C died and IC1 needs
replaced,
> or perhaps the control voltages off deMUX IC19 aren't getting there
and
> IC19, IC12 or IC13 is to blame (least likely though).
>
> Use my schematic as it is much easier to read than the old
service
> manual copy. PWM circuit is on the far right, about 2/3 of the way
down.
> It is marked "PWM MG":
>
>
http://www.oldcrows.net/~oldcrow/synth/korg/polysix/crowlm367/klm367a_
eagle_schem.gif
>
>
> Hope this helps,
>
> Crow
> /**/
>
> On Wed, 31 Dec 2003, ciscomanvann wrote:
>
> > I know this sounds stupid, but how can i tell if the PWM is
working?
> > If it is not, where do I start looking to fix it?
> > Thanks!

On KLM-367 check the following:
* IC12 (TL072) pin1: must be -5V .. +5V according to PW/PWM poti
if not, replace IC12
* IC13 (4558) pin1: must be -5V .. +5V according to PWM SPEED poti
if not, replace IC13
* Set PWM SPEED to slowest and check IC1 (4066)/pin9: must change from
minus to plus voltage and back (I dont know the exact values; will
be at least -3V..+3V)
if not, replace IC20 (LM13600) and/or IC15 (4558)
* IC1/pin6: must be +5V when WAVEFORM is at PWM position, otherwise 0V.
if not, replace IC3 (LM339)
* IC1/pin8: must be the same as IC1/pin9 when WAVEFORM is at PWM
position, if not replace IC1 (4066).
* TP1 (PW/PWM) near IC12: according to service manual "PW/PWM check
and adjustment"
if not OK, replace IC20 (LM13600) and/or IC15 (4558)

I hope this helps,

Johannes


ciscomanvann wrote:

> Nothing happens. It plays, but the width or pwm does not change. I
> have a multimeter, how do i check this stuff out? I dont know a whole
> lot about ICs.
>
> --- In PolySix@yahoogroups.com, The Old Crow <oldcrow@o...> wrote:
>
>> First thing to do is set VCO to PW and move the width knob from 0
>
> to 10
>
>>and back to 0 and listen to see if it changes accordingly. Then
>
> set it to
>
>>10 and change the VCO mode to PWM and move the PWM speed knob from
>
> 0 to 10
>
>>slowly and note if the cyclic modulation is audible.
>>
>> If nothing is working then I would imagine either IC20 (LM13600)
>
> needs
>
>>replaced, or the analog switch section IC1C died and IC1 needs
>
> replaced,
>
>>or perhaps the control voltages off deMUX IC19 aren't getting there
>
> and
>
>>IC19, IC12 or IC13 is to blame (least likely though).
>>
>> Use my schematic as it is much easier to read than the old
>
> service
>
>>manual copy. PWM circuit is on the far right, about 2/3 of the way
>
> down.
>
>>It is marked "PWM MG":
>>
>>
>
> http://www.oldcrows.net/~oldcrow/synth/korg/polysix/crowlm367/klm367a_
> eagle_schem.gif
>
>>
>> Hope this helps,
>>
>>Crow
>>/**/
>>
>>On Wed, 31 Dec 2003, ciscomanvann wrote:
>>
>>
>>>I know this sounds stupid, but how can i tell if the PWM is
>
> working?
>
>>>If it is not, where do I start looking to fix it?
>>>Thanks!
>
>
>
> PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
>
> Yahoo! Groups Links
>
> To visit your group on the web, go to:
> http://groups.yahoo.com/group/PolySix/
>
> To unsubscribe from this group, send an email to:
> PolySix-unsubscribe@yahoogroups.com
>
> Your use of Yahoo! Groups is subject to:
> http://docs.yahoo.com/info/terms/
>
>
>
>

Thanks so much!
I will break out the meter tonight and let you know what I find. I
REALLY do appreciate it as while this synth arrived in pristine shape,
I can only get a saw and basic square out of it. I really do want to
get the PWM fixed.
Thanks again!

--- In PolySix@yahoogroups.com, Johannes Hausensteiner <jo.synth@c...>
wrote:

> On KLM-367 check the following:
> * IC12 (TL072) pin1: must be -5V .. +5V according to PW/PWM poti
> if not, replace IC12
> * IC13 (4558) pin1: must be -5V .. +5V according to PWM SPEED poti
> if not, replace IC13
> * Set PWM SPEED to slowest and check IC1 (4066)/pin9: must change from
> minus to plus voltage and back (I dont know the exact values; will
> be at least -3V..+3V)
> if not, replace IC20 (LM13600) and/or IC15 (4558)
> * IC1/pin6: must be +5V when WAVEFORM is at PWM position, otherwise 0V.
> if not, replace IC3 (LM339)
> * IC1/pin8: must be the same as IC1/pin9 when WAVEFORM is at PWM
> position, if not replace IC1 (4066).
> * TP1 (PW/PWM) near IC12: according to service manual "PW/PWM check
> and adjustment"
> if not OK, replace IC20 (LM13600) and/or IC15 (4558)
>
> I hope this helps,
>
> Johannes
>
>
> ciscomanvann wrote:
> > Nothing happens. It plays, but the width or pwm does not change. I
> > have a multimeter, how do i check this stuff out? I dont know a whole
> > lot about ICs.
> >
> > --- In PolySix@yahoogroups.com, The Old Crow <oldcrow@o...> wrote:
> >
> >> First thing to do is set VCO to PW and move the width knob from 0
> >
> > to 10
> >
> >>and back to 0 and listen to see if it changes accordingly. Then
> >
> > set it to
> >
> >>10 and change the VCO mode to PWM and move the PWM speed knob from
> >
> > 0 to 10
> >
> >>slowly and note if the cyclic modulation is audible.
> >>
> >> If nothing is working then I would imagine either IC20 (LM13600)
> >
> > needs
> >
> >>replaced, or the analog switch section IC1C died and IC1 needs
> >
> > replaced,
> >
> >>or perhaps the control voltages off deMUX IC19 aren't getting there
> >
> > and
> >
> >>IC19, IC12 or IC13 is to blame (least likely though).
> >>
> >> Use my schematic as it is much easier to read than the old
> >
> > service
> >
> >>manual copy. PWM circuit is on the far right, about 2/3 of the way
> >
> > down.
> >
> >>It is marked "PWM MG":
> >>
> >>
> >
> > http://www.oldcrows.net/~oldcrow/synth/korg/polysix/crowlm367/klm367a_
> > eagle_schem.gif
> >
> >>
> >> Hope this helps,
> >>
> >>Crow
> >>/**/
> >>
> >>On Wed, 31 Dec 2003, ciscomanvann wrote:
> >>
> >>
> >>>I know this sounds stupid, but how can i tell if the PWM is
> >
> > working?
> >
> >>>If it is not, where do I start looking to fix it?
> >>>Thanks!
> >
> >
> >
> > PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> >
> > Yahoo! Groups Links
> >
> > To visit your group on the web, go to:
> > http://groups.yahoo.com/group/PolySix/
> >
> > To unsubscribe from this group, send an email to:
> > PolySix-unsubscribe@yahoogroups.com
> >
> > Your use of Yahoo! Groups is subject to:
> > http://docs.yahoo.com/info/terms/
> >
> >
> >
> >

OK, when I am looking at the IC how do i know which pin is pin 1? I
found one pin on IC12 that measures +/- 4.7 v but no pin that changes
on IC13. Hmm

--- In PolySix@yahoogroups.com, Johannes Hausensteiner <jo.synth@c...>
wrote:

> On KLM-367 check the following:
> * IC12 (TL072) pin1: must be -5V .. +5V according to PW/PWM poti
> if not, replace IC12
> * IC13 (4558) pin1: must be -5V .. +5V according to PWM SPEED poti
> if not, replace IC13
> * Set PWM SPEED to slowest and check IC1 (4066)/pin9: must change from
> minus to plus voltage and back (I dont know the exact values; will
> be at least -3V..+3V)
> if not, replace IC20 (LM13600) and/or IC15 (4558)
> * IC1/pin6: must be +5V when WAVEFORM is at PWM position, otherwise 0V.
> if not, replace IC3 (LM339)
> * IC1/pin8: must be the same as IC1/pin9 when WAVEFORM is at PWM
> position, if not replace IC1 (4066).
> * TP1 (PW/PWM) near IC12: according to service manual "PW/PWM check
> and adjustment"
> if not OK, replace IC20 (LM13600) and/or IC15 (4558)
>
> I hope this helps,
>
> Johannes
>
>
> ciscomanvann wrote:
> > Nothing happens. It plays, but the width or pwm does not change. I
> > have a multimeter, how do i check this stuff out? I dont know a whole
> > lot about ICs.
> >
> > --- In PolySix@yahoogroups.com, The Old Crow <oldcrow@o...> wrote:
> >
> >> First thing to do is set VCO to PW and move the width knob from 0
> >
> > to 10
> >
> >>and back to 0 and listen to see if it changes accordingly. Then
> >
> > set it to
> >
> >>10 and change the VCO mode to PWM and move the PWM speed knob from
> >
> > 0 to 10
> >
> >>slowly and note if the cyclic modulation is audible.
> >>
> >> If nothing is working then I would imagine either IC20 (LM13600)
> >
> > needs
> >
> >>replaced, or the analog switch section IC1C died and IC1 needs
> >
> > replaced,
> >
> >>or perhaps the control voltages off deMUX IC19 aren't getting there
> >
> > and
> >
> >>IC19, IC12 or IC13 is to blame (least likely though).
> >>
> >> Use my schematic as it is much easier to read than the old
> >
> > service
> >
> >>manual copy. PWM circuit is on the far right, about 2/3 of the way
> >
> > down.
> >
> >>It is marked "PWM MG":
> >>
> >>
> >
> > http://www.oldcrows.net/~oldcrow/synth/korg/polysix/crowlm367/klm367a_
> > eagle_schem.gif
> >
> >>
> >> Hope this helps,
> >>
> >>Crow
> >>/**/
> >>
> >>On Wed, 31 Dec 2003, ciscomanvann wrote:
> >>
> >>
> >>>I know this sounds stupid, but how can i tell if the PWM is
> >
> > working?
> >
> >>>If it is not, where do I start looking to fix it?
> >>>Thanks!
> >
> >
> >
> > PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> >
> > Yahoo! Groups Links
> >
> > To visit your group on the web, go to:
> > http://groups.yahoo.com/group/PolySix/
> >
> > To unsubscribe from this group, send an email to:
> > PolySix-unsubscribe@yahoogroups.com
> >
> > Your use of Yahoo! Groups is subject to:
> > http://docs.yahoo.com/info/terms/
> >
> >
> >
> >

Crow,
When are you going to add the section to your site titled, " Give Your
Polysix a Korg PS3100-style Triple Resonant Filter " ? Also, is it
possible to replace the 2044 with a 2040 filter? I know i am getting
ahead of myself since I can not get get my PWM working but I just cant
help it.

--- In PolySix@yahoogroups.com, Johannes Hausensteiner <jo.synth@c...>
wrote:

> On KLM-367 check the following:
> * IC12 (TL072) pin1: must be -5V .. +5V according to PW/PWM poti
> if not, replace IC12
> * IC13 (4558) pin1: must be -5V .. +5V according to PWM SPEED poti
> if not, replace IC13
> * Set PWM SPEED to slowest and check IC1 (4066)/pin9: must change from
> minus to plus voltage and back (I dont know the exact values; will
> be at least -3V..+3V)
> if not, replace IC20 (LM13600) and/or IC15 (4558)
> * IC1/pin6: must be +5V when WAVEFORM is at PWM position, otherwise 0V.
> if not, replace IC3 (LM339)
> * IC1/pin8: must be the same as IC1/pin9 when WAVEFORM is at PWM
> position, if not replace IC1 (4066).
> * TP1 (PW/PWM) near IC12: according to service manual "PW/PWM check
> and adjustment"
> if not OK, replace IC20 (LM13600) and/or IC15 (4558)
>
> I hope this helps,
>
> Johannes
>
>
> ciscomanvann wrote:
> > Nothing happens. It plays, but the width or pwm does not change. I
> > have a multimeter, how do i check this stuff out? I dont know a whole
> > lot about ICs.
> >
> > --- In PolySix@yahoogroups.com, The Old Crow <oldcrow@o...> wrote:
> >
> >> First thing to do is set VCO to PW and move the width knob from 0
> >
> > to 10
> >
> >>and back to 0 and listen to see if it changes accordingly. Then
> >
> > set it to
> >
> >>10 and change the VCO mode to PWM and move the PWM speed knob from
> >
> > 0 to 10
> >
> >>slowly and note if the cyclic modulation is audible.
> >>
> >> If nothing is working then I would imagine either IC20 (LM13600)
> >
> > needs
> >
> >>replaced, or the analog switch section IC1C died and IC1 needs
> >
> > replaced,
> >
> >>or perhaps the control voltages off deMUX IC19 aren't getting there
> >
> > and
> >
> >>IC19, IC12 or IC13 is to blame (least likely though).
> >>
> >> Use my schematic as it is much easier to read than the old
> >
> > service
> >
> >>manual copy. PWM circuit is on the far right, about 2/3 of the way
> >
> > down.
> >
> >>It is marked "PWM MG":
> >>
> >>
> >
> > http://www.oldcrows.net/~oldcrow/synth/korg/polysix/crowlm367/klm367a_
> > eagle_schem.gif
> >
> >>
> >> Hope this helps,
> >>
> >>Crow
> >>/**/
> >>
> >>On Wed, 31 Dec 2003, ciscomanvann wrote:
> >>
> >>
> >>>I know this sounds stupid, but how can i tell if the PWM is
> >
> > working?
> >
> >>>If it is not, where do I start looking to fix it?
> >>>Thanks!
> >
> >
> >
> > PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> >
> > Yahoo! Groups Links
> >
> > To visit your group on the web, go to:
> > http://groups.yahoo.com/group/PolySix/
> >
> > To unsubscribe from this group, send an email to:
> > PolySix-unsubscribe@yahoogroups.com
> >
> > Your use of Yahoo! Groups is subject to:
> > http://docs.yahoo.com/info/terms/
> >
> >
> >
> >

Hm, I still need to do that triple res. mod website. Right after I do
the 2nd VCO for Polysix site. ;)

The 2040 is not a drop-in for the 2044. A 2040 can be made to operate
as a 2044 (the 2044 is a hardwired lowpass, the 2040 is just four filter
'cells' than can be wired for other filter modes besides lowpass).
However, 2040s are harder to find than 2044s. I see 2044s on ebay all the
time for reasonable prices.

Crow
/**/

On Sun, 11 Jan 2004, ciscomanvann wrote:

> Crow,
>
> When are you going to add the section to your site titled, " Give Your
> Polysix a Korg PS3100-style Triple Resonant Filter " ? Also, is it
> possible to replace the 2044 with a 2040 filter? I know i am getting
> ahead of myself since I can not get get my PWM working but I just cant
> help it.

Hi,

How to determine the pin number of an IC:

e.g. DIL-8 case:


8 7 6 5
+|-|-|-|+
notch: > |
+|-|-|-|+
1 2 3 4
^
pin no. one

I hope this helps ...

ciscomanvann wrote:

> OK, when I am looking at the IC how do i know which pin is pin 1? I
> found one pin on IC12 that measures +/- 4.7 v but no pin that changes
> on IC13. Hmm
>
> --- In PolySix@yahoogroups.com, Johannes Hausensteiner <jo.synth@c...>
> wrote:
>
>>On KLM-367 check the following:
>>* IC12 (TL072) pin1: must be -5V .. +5V according to PW/PWM poti
>> if not, replace IC12
>>* IC13 (4558) pin1: must be -5V .. +5V according to PWM SPEED poti
>> if not, replace IC13
>>* Set PWM SPEED to slowest and check IC1 (4066)/pin9: must change from
>> minus to plus voltage and back (I dont know the exact values; will
>> be at least -3V..+3V)
>> if not, replace IC20 (LM13600) and/or IC15 (4558)
>>* IC1/pin6: must be +5V when WAVEFORM is at PWM position, otherwise 0V.
>> if not, replace IC3 (LM339)
>>* IC1/pin8: must be the same as IC1/pin9 when WAVEFORM is at PWM
>> position, if not replace IC1 (4066).
>>* TP1 (PW/PWM) near IC12: according to service manual "PW/PWM check
>> and adjustment"
>> if not OK, replace IC20 (LM13600) and/or IC15 (4558)
>>
>>I hope this helps,
>>
>>Johannes
>>
>>
>>ciscomanvann wrote:
>>
>>>Nothing happens. It plays, but the width or pwm does not change. I
>>>have a multimeter, how do i check this stuff out? I dont know a whole
>>>lot about ICs.
>>>
>>>--- In PolySix@yahoogroups.com, The Old Crow <oldcrow@o...> wrote:
>>>
>>>
>>>> First thing to do is set VCO to PW and move the width knob from 0
>>>
>>>to 10
>>>
>>>
>>>>and back to 0 and listen to see if it changes accordingly. Then
>>>
>>>set it to
>>>
>>>
>>>>10 and change the VCO mode to PWM and move the PWM speed knob from
>>>
>>>0 to 10
>>>
>>>
>>>>slowly and note if the cyclic modulation is audible.
>>>>
>>>> If nothing is working then I would imagine either IC20 (LM13600)
>>>
>>>needs
>>>
>>>
>>>>replaced, or the analog switch section IC1C died and IC1 needs
>>>
>>>replaced,
>>>
>>>
>>>>or perhaps the control voltages off deMUX IC19 aren't getting there
>>>
>>>and
>>>
>>>
>>>>IC19, IC12 or IC13 is to blame (least likely though).
>>>>
>>>> Use my schematic as it is much easier to read than the old
>>>
>>>service
>>>
>>>
>>>>manual copy. PWM circuit is on the far right, about 2/3 of the way
>>>
>>>down.
>>>
>>>
>>>>It is marked "PWM MG":
>>>>
>>>>
>>>
>>>http://www.oldcrows.net/~oldcrow/synth/korg/polysix/crowlm367/klm367a_
>>>eagle_schem.gif
>>>
>>>
>>>> Hope this helps,
>>>>
>>>>Crow
>>>>/**/
>>>>
>>>>On Wed, 31 Dec 2003, ciscomanvann wrote:
>>>>
>>>>
>>>>
>>>>>I know this sounds stupid, but how can i tell if the PWM is
>>>
>>>working?
>>>
>>>
>>>>>If it is not, where do I start looking to fix it?
>>>>>Thanks!
>>>
>>>
>>>
>>>PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
>>>
>>>Yahoo! Groups Links
>>>
>>>To visit your group on the web, go to:
>>> http://groups.yahoo.com/group/PolySix/
>>>
>>>To unsubscribe from this group, send an email to:
>>> PolySix-unsubscribe@yahoogroups.com
>>>
>>>Your use of Yahoo! Groups is subject to:
>>> http://docs.yahoo.com/info/terms/
>>>
>>>
>>>
>>>
>
>
>
> PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
>
> Yahoo! Groups Links
>
> To visit your group on the web, go to:
> http://groups.yahoo.com/group/PolySix/
>
> To unsubscribe from this group, send an email to:
> PolySix-unsubscribe@yahoogroups.com
>
> Your use of Yahoo! Groups is subject to:
> http://docs.yahoo.com/info/terms/
>
>
>
>

Eh, i just like the sound of a 2040. Soooo, how about you mod my polysix to use
2040's and make them bandpass, highpass and lowpass :-)

--- In PolySix@yahoogroups.com, The Old Crow <oldcrow@o...> wrote:
>
> Hm, I still need to do that triple res. mod website. Right after I do
> the 2nd VCO for Polysix site. ;)
>
> The 2040 is not a drop-in for the 2044. A 2040 can be made to operate
> as a 2044 (the 2044 is a hardwired lowpass, the 2040 is just four filter
> 'cells' than can be wired for other filter modes besides lowpass).
> However, 2040s are harder to find than 2044s. I see 2044s on ebay all the
> time for reasonable prices.
>
> Crow
> /**/
>
> On Sun, 11 Jan 2004, ciscomanvann wrote:
>
> > Crow,
> >
> > When are you going to add the section to your site titled, " Give Your
> > Polysix a Korg PS3100-style Triple Resonant Filter " ? Also, is it
> > possible to replace the 2044 with a 2040 filter? I know i am getting
> > ahead of myself since I can not get get my PWM working but I just cant
> > help it.

Well, if that is the case ic13 is craped out. Would that cause my synth to play when in
PWM mode but not be able to change the PWM shape or speed?

--- In PolySix@yahoogroups.com, Johannes Hausensteiner <jo.synth@c...> wrote:
> Hi,
>
> How to determine the pin number of an IC:
>
> e.g. DIL-8 case:
>
>
> 8 7 6 5
> +|-|-|-|+
> notch: > |
> +|-|-|-|+
> 1 2 3 4
> ^
> pin no. one
>
> I hope this helps ...
>
> ciscomanvann wrote:
> > OK, when I am looking at the IC how do i know which pin is pin 1? I
> > found one pin on IC12 that measures +/- 4.7 v but no pin that changes
> > on IC13. Hmm
> >
> > --- In PolySix@yahoogroups.com, Johannes Hausensteiner <jo.synth@c...>
> > wrote:
> >
> >>On KLM-367 check the following:
> >>* IC12 (TL072) pin1: must be -5V .. +5V according to PW/PWM poti
> >> if not, replace IC12
> >>* IC13 (4558) pin1: must be -5V .. +5V according to PWM SPEED poti
> >> if not, replace IC13
> >>* Set PWM SPEED to slowest and check IC1 (4066)/pin9: must change from
> >> minus to plus voltage and back (I dont know the exact values; will
> >> be at least -3V..+3V)
> >> if not, replace IC20 (LM13600) and/or IC15 (4558)
> >>* IC1/pin6: must be +5V when WAVEFORM is at PWM position, otherwise 0V.
> >> if not, replace IC3 (LM339)
> >>* IC1/pin8: must be the same as IC1/pin9 when WAVEFORM is at PWM
> >> position, if not replace IC1 (4066).
> >>* TP1 (PW/PWM) near IC12: according to service manual "PW/PWM check
> >> and adjustment"
> >> if not OK, replace IC20 (LM13600) and/or IC15 (4558)
> >>
> >>I hope this helps,
> >>
> >>Johannes
> >>
> >>
> >>ciscomanvann wrote:
> >>
> >>>Nothing happens. It plays, but the width or pwm does not change. I
> >>>have a multimeter, how do i check this stuff out? I dont know a whole
> >>>lot about ICs.
> >>>
> >>>--- In PolySix@yahoogroups.com, The Old Crow <oldcrow@o...> wrote:
> >>>
> >>>
> >>>> First thing to do is set VCO to PW and move the width knob from 0
> >>>
> >>>to 10
> >>>
> >>>
> >>>>and back to 0 and listen to see if it changes accordingly. Then
> >>>
> >>>set it to
> >>>
> >>>
> >>>>10 and change the VCO mode to PWM and move the PWM speed knob from
> >>>
> >>>0 to 10
> >>>
> >>>
> >>>>slowly and note if the cyclic modulation is audible.
> >>>>
> >>>> If nothing is working then I would imagine either IC20 (LM13600)
> >>>
> >>>needs
> >>>
> >>>
> >>>>replaced, or the analog switch section IC1C died and IC1 needs
> >>>
> >>>replaced,
> >>>
> >>>
> >>>>or perhaps the control voltages off deMUX IC19 aren't getting there
> >>>
> >>>and
> >>>
> >>>
> >>>>IC19, IC12 or IC13 is to blame (least likely though).
> >>>>
> >>>> Use my schematic as it is much easier to read than the old
> >>>
> >>>service
> >>>
> >>>
> >>>>manual copy. PWM circuit is on the far right, about 2/3 of the way
> >>>
> >>>down.
> >>>
> >>>
> >>>>It is marked "PWM MG":
> >>>>
> >>>>
> >>>
> >>>http://www.oldcrows.net/~oldcrow/synth/korg/polysix/crowlm367/klm367a_
> >>>eagle_schem.gif
> >>>
> >>>
> >>>> Hope this helps,
> >>>>
> >>>>Crow
> >>>>/**/
> >>>>
> >>>>On Wed, 31 Dec 2003, ciscomanvann wrote:
> >>>>
> >>>>
> >>>>
> >>>>>I know this sounds stupid, but how can i tell if the PWM is
> >>>
> >>>working?
> >>>
> >>>
> >>>>>If it is not, where do I start looking to fix it?
> >>>>>Thanks!
> >>>
> >>>
> >>>
> >>>PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> >>>
> >>>Yahoo! Groups Links
> >>>
> >>>To visit your group on the web, go to:
> >>> http://groups.yahoo.com/group/PolySix/
> >>>
> >>>To unsubscribe from this group, send an email to:
> >>> PolySix-unsubscribe@yahoogroups.com
> >>>
> >>>Your use of Yahoo! Groups is subject to:
> >>> http://docs.yahoo.com/info/terms/
> >>>
> >>>
> >>>
> >>>
> >
> >
> >
> > PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> >
> > Yahoo! Groups Links
> >
> > To visit your group on the web, go to:
> > http://groups.yahoo.com/group/PolySix/
> >
> > To unsubscribe from this group, send an email to:
> > PolySix-unsubscribe@yahoogroups.com
> >
> > Your use of Yahoo! Groups is subject to:
> > http://docs.yahoo.com/info/terms/
> >
> >
> >
> >

Yes. When you measure on pin1 there will be a certain voltage. The
PWM SPEED will be fixed at this point.
When you measure at IC13/pin3, does the voltage change according to
the PWM SPEED pot? If yes, replace IC13. If no, then IC19 (4051 analog
mux/demux) may be the reason.
Do you have access to an oscilloscope? This would speed up searching
for the defective component...

Johannes


ciscomanvann wrote:

> Well, if that is the case ic13 is craped out. Would that cause my synth to play when in
> PWM mode but not be able to change the PWM shape or speed?
>
> --- In PolySix@yahoogroups.com, Johannes Hausensteiner <jo.synth@c...> wrote:
>
>>Hi,
>>
>>How to determine the pin number of an IC:
>>
>>e.g. DIL-8 case:
>>
>>
>> 8 7 6 5
>> +|-|-|-|+
>>notch: > |
>> +|-|-|-|+
>> 1 2 3 4
>> ^
>>pin no. one
>>
>>I hope this helps ...
>>
>>ciscomanvann wrote:
>>
>>>OK, when I am looking at the IC how do i know which pin is pin 1? I
>>>found one pin on IC12 that measures +/- 4.7 v but no pin that changes
>>>on IC13. Hmm
>>>
>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner <jo.synth@c...>
>>>wrote:
>>>
>>>
>>>>On KLM-367 check the following:
>>>>* IC12 (TL072) pin1: must be -5V .. +5V according to PW/PWM poti
>>>> if not, replace IC12
>>>>* IC13 (4558) pin1: must be -5V .. +5V according to PWM SPEED poti
>>>> if not, replace IC13
>>>>* Set PWM SPEED to slowest and check IC1 (4066)/pin9: must change from
>>>> minus to plus voltage and back (I dont know the exact values; will
>>>> be at least -3V..+3V)
>>>> if not, replace IC20 (LM13600) and/or IC15 (4558)
>>>>* IC1/pin6: must be +5V when WAVEFORM is at PWM position, otherwise 0V.
>>>> if not, replace IC3 (LM339)
>>>>* IC1/pin8: must be the same as IC1/pin9 when WAVEFORM is at PWM
>>>> position, if not replace IC1 (4066).
>>>>* TP1 (PW/PWM) near IC12: according to service manual "PW/PWM check
>>>> and adjustment"
>>>> if not OK, replace IC20 (LM13600) and/or IC15 (4558)
>>>>
>>>>I hope this helps,
>>>>
>>>>Johannes
>>>>
>>>>
>>>>ciscomanvann wrote:
>>>>
>>>>
>>>>>Nothing happens. It plays, but the width or pwm does not change. I
>>>>>have a multimeter, how do i check this stuff out? I dont know a whole
>>>>>lot about ICs.
>>>>>
>>>>>--- In PolySix@yahoogroups.com, The Old Crow <oldcrow@o...> wrote:
>>>>>
>>>>>
>>>>>
>>>>>>First thing to do is set VCO to PW and move the width knob from 0
>>>>>
>>>>>to 10
>>>>>
>>>>>
>>>>>
>>>>>>and back to 0 and listen to see if it changes accordingly. Then
>>>>>
>>>>>set it to
>>>>>
>>>>>
>>>>>
>>>>>>10 and change the VCO mode to PWM and move the PWM speed knob from
>>>>>
>>>>>0 to 10
>>>>>
>>>>>
>>>>>
>>>>>>slowly and note if the cyclic modulation is audible.
>>>>>>
>>>>>>If nothing is working then I would imagine either IC20 (LM13600)
>>>>>
>>>>>needs
>>>>>
>>>>>
>>>>>
>>>>>>replaced, or the analog switch section IC1C died and IC1 needs
>>>>>
>>>>>replaced,
>>>>>
>>>>>
>>>>>
>>>>>>or perhaps the control voltages off deMUX IC19 aren't getting there
>>>>>
>>>>>and
>>>>>
>>>>>
>>>>>
>>>>>>IC19, IC12 or IC13 is to blame (least likely though).
>>>>>>
>>>>>>Use my schematic as it is much easier to read than the old
>>>>>
>>>>>service
>>>>>
>>>>>
>>>>>
>>>>>>manual copy. PWM circuit is on the far right, about 2/3 of the way
>>>>>
>>>>>down.
>>>>>
>>>>>
>>>>>
>>>>>>It is marked "PWM MG":
>>>>>>
>>>>>>
>>>>>
>>>>>http://www.oldcrows.net/~oldcrow/synth/korg/polysix/crowlm367/klm367a_
>>>>>eagle_schem.gif
>>>>>
>>>>>
>>>>>
>>>>>>Hope this helps,
>>>>>>
>>>>>>Crow
>>>>>>/**/
>>>>>>
>>>>>>On Wed, 31 Dec 2003, ciscomanvann wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>>I know this sounds stupid, but how can i tell if the PWM is
>>>>>
>>>>>working?
>>>>>
>>>>>
>>>>>
>>>>>>>If it is not, where do I start looking to fix it?
>>>>>>>Thanks!
>>>>>
>>>>>
>>>>>
>>>>>PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
>>>>>
>>>>>Yahoo! Groups Links
>>>>>
>>>>>To visit your group on the web, go to:
>>>>>http://groups.yahoo.com/group/PolySix/
>>>>>
>>>>>To unsubscribe from this group, send an email to:
>>>>>PolySix-unsubscribe@yahoogroups.com
>>>>>
>>>>>Your use of Yahoo! Groups is subject to:
>>>>>http://docs.yahoo.com/info/terms/
>>>>>
>>>>>
>>>>>
>>>>>
>>>
>>>
>>>
>>>PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
>>>
>>>Yahoo! Groups Links
>>>
>>>To visit your group on the web, go to:
>>> http://groups.yahoo.com/group/PolySix/
>>>
>>>To unsubscribe from this group, send an email to:
>>> PolySix-unsubscribe@yahoogroups.com
>>>
>>>Your use of Yahoo! Groups is subject to:
>>> http://docs.yahoo.com/info/terms/
>>>
>>>
>>>
>>>
>
>
>
> PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
>
> Yahoo! Groups Links
>
> To visit your group on the web, go to:
> http://groups.yahoo.com/group/PolySix/
>
> To unsubscribe from this group, send an email to:
> PolySix-unsubscribe@yahoogroups.com
>
> Your use of Yahoo! Groups is subject to:
> http://docs.yahoo.com/info/terms/
>
>
>
>

Eh,
I just checked pins 1 and 3 of ic13 and they both read 4.97 volts. I
thought they read different before but maybe i was doing something
wrong. Any ideas?