Discussion about the Korg PolySix synthesizer group photo

Yahoo Groups archive

Discussion about the Korg PolySix synthesizer

Index last updated: 2026-04-03 01:39 UTC

Thread

Notes go out of pitch

Notes go out of pitch

2004-01-19 by Peter Andersson

Hi all,

I'm the proud new owner of a Polysix. I love it! Can't take my hands 
off those knobs - the filters are just great! But I'm having a 
problem with it and I'm hoping someone can tell me what it's about 
and maybe even what can be done...

After I've played the synth for a while, notes start to go out of 
pitch every now and then. It happens randomly every 10-30 sec or so. 
The notes go off pitch with a note or so and always jump or slide 
back to the original pitch again within half a second.

At first I thought it was some filter setting of mine that caused 
it, but as it turns out I get this no matter how the Poly6 is 
programmed (or if I use a preset or a fresh "manual" sound). (By the 
way, it takes about 20 minutes for the unit to get in perfect tune 
after a cold start. Don't know if that's normal or if it's related 
to this problem in any way).

I'd be truly grateful for any help!

Peter

Re: [PolySix] Notes go out of pitch

2004-01-20 by Johannes Hausensteiner

It is not normal that it takes 20 miuntes to tune up. Usually it
takes about 10sec to tune and then it is quite stable.
Check the following: hold a key down when switching power on. The
generated note should change quite a lot until it stabilizes after
a few secs.
Are all six voice affected? Is the effect related to the MG setting
(VCA/VCF/VCO)? Is it related to PWM setting?


Peter Andersson wrote:
Show quoted textHide quoted text
> Hi all,
> 
> I'm the proud new owner of a Polysix. I love it! Can't take my hands 
> off those knobs - the filters are just great! But I'm having a 
> problem with it and I'm hoping someone can tell me what it's about 
> and maybe even what can be done...
> 
> After I've played the synth for a while, notes start to go out of 
> pitch every now and then. It happens randomly every 10-30 sec or so. 
> The notes go off pitch with a note or so and always jump or slide 
> back to the original pitch again within half a second.
> 
> At first I thought it was some filter setting of mine that caused 
> it, but as it turns out I get this no matter how the Poly6 is 
> programmed (or if I use a preset or a fresh "manual" sound). (By the 
> way, it takes about 20 minutes for the unit to get in perfect tune 
> after a cold start. Don't know if that's normal or if it's related 
> to this problem in any way).
> 
> I'd be truly grateful for any help!
> 
> Peter
> 
> 
> 
> 
> 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/ 
> 
> 
> 
>

Re: Notes go out of pitch

2004-01-21 by Peter Andersson

Actually, tones are quite stable even during the first 20 minutes, but
the synth is not in tune generally. Also, an octave is a quite stable
major 7 interval for the first 20 minutes, until suddenly, the synth
goes into tune and then the octave is correct as well. I'll check
tonight if a single generated tone changes a lot during the first 10
sec.

All six voices are affected. If I play a chord when it suddenly slides
out of pitch, all notes follow. It actually sounds like I'm turning
the pitch wheel. (I disconnected the pitch wheel, btw, just to be sure
it wasn't playing tricks on me).

It is not related to the MG setting and I've played around with all
three - VCA, VCF and VCO. I'm quite sure it's not affected by the
waveform setting either (whether I use a saw or a pulse) but I'll
double check that tonight. The PWM setting does not make any
difference.

Does this give you any clues? Thanks for helping!


--- In PolySix@yahoogroups.com, Johannes Hausensteiner <jo.synth@c...>
wrote:
> It is not normal that it takes 20 miuntes to tune up. Usually it
> takes about 10sec to tune and then it is quite stable.
> Check the following: hold a key down when switching power on. The
> generated note should change quite a lot until it stabilizes after
> a few secs.
> Are all six voice affected? Is the effect related to the MG setting
> (VCA/VCF/VCO)? Is it related to PWM setting?
> 
> 
> Peter Andersson wrote:
> 
> > Hi all,
> > 
> > I'm the proud new owner of a Polysix. I love it! Can't take my
hands 
> > off those knobs - the filters are just great! But I'm having a 
> > problem with it and I'm hoping someone can tell me what it's
about 
> > and maybe even what can be done...
> > 
> > After I've played the synth for a while, notes start to go out of 
> > pitch every now and then. It happens randomly every 10-30 sec or
so. 
> > The notes go off pitch with a note or so and always jump or slide 
> > back to the original pitch again within half a second.
> > 
> > At first I thought it was some filter setting of mine that caused 
> > it, but as it turns out I get this no matter how the Poly6 is 
> > programmed (or if I use a preset or a fresh "manual" sound). (By
the 
> > way, it takes about 20 minutes for the unit to get in perfect
tune 
> > after a cold start. Don't know if that's normal or if it's
related 
Show quoted textHide quoted text
> > to this problem in any way).
> > 
> > I'd be truly grateful for any help!
> > 
> > Peter
> > 
> > 
> > 
> > 
> > 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/ 
> > 
> > 
> > 
> >

Re: [PolySix] Re: Notes go out of pitch

2004-01-21 by Johannes Hausensteiner

From what you tell I would say it is a problem on the KLM-366, in
the log/lin conversion/tuning section.
Or maybe you have one of the rare "old production" units. Is there
a small add-on board "KLM-396" to the KLM-366?
It could be a lose wire (if "old production") and/or a bad solder
joint.
I can see that you are located in Sweden; maybe you ask Ricard
( http://home.swipnet.se/ricard2/p6index.html ) for technical help.


Peter Andersson wrote:
Show quoted textHide quoted text
> Actually, tones are quite stable even during the first 20 minutes, but
> the synth is not in tune generally. Also, an octave is a quite stable
> major 7 interval for the first 20 minutes, until suddenly, the synth
> goes into tune and then the octave is correct as well. I'll check
> tonight if a single generated tone changes a lot during the first 10
> sec.
> 
> All six voices are affected. If I play a chord when it suddenly slides
> out of pitch, all notes follow. It actually sounds like I'm turning
> the pitch wheel. (I disconnected the pitch wheel, btw, just to be sure
> it wasn't playing tricks on me).
> 
> It is not related to the MG setting and I've played around with all
> three - VCA, VCF and VCO. I'm quite sure it's not affected by the
> waveform setting either (whether I use a saw or a pulse) but I'll
> double check that tonight. The PWM setting does not make any
> difference.
> 
> Does this give you any clues? Thanks for helping!
> 
> 
> --- In PolySix@yahoogroups.com, Johannes Hausensteiner <jo.synth@c...>
> wrote:
> 
>>It is not normal that it takes 20 miuntes to tune up. Usually it
>>takes about 10sec to tune and then it is quite stable.
>>Check the following: hold a key down when switching power on. The
>>generated note should change quite a lot until it stabilizes after
>>a few secs.
>>Are all six voice affected? Is the effect related to the MG setting
>>(VCA/VCF/VCO)? Is it related to PWM setting?
>>
>>
>>Peter Andersson wrote:
>>
>>
>>>Hi all,
>>>
>>>I'm the proud new owner of a Polysix. I love it! Can't take my
> 
> hands 
> 
>>>off those knobs - the filters are just great! But I'm having a 
>>>problem with it and I'm hoping someone can tell me what it's
> 
> about 
> 
>>>and maybe even what can be done...
>>>
>>>After I've played the synth for a while, notes start to go out of 
>>>pitch every now and then. It happens randomly every 10-30 sec or
> 
> so. 
> 
>>>The notes go off pitch with a note or so and always jump or slide 
>>>back to the original pitch again within half a second.
>>>
>>>At first I thought it was some filter setting of mine that caused 
>>>it, but as it turns out I get this no matter how the Poly6 is 
>>>programmed (or if I use a preset or a fresh "manual" sound). (By
> 
> the 
> 
>>>way, it takes about 20 minutes for the unit to get in perfect
> 
> tune 
> 
>>>after a cold start. Don't know if that's normal or if it's
> 
> related 
> 
>>>to this problem in any way).
>>>
>>>I'd be truly grateful for any help!
>>>
>>>Peter
>>>
>>>
>>>
>>>
>>>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/ 
> 
> 
> 
>

Re: Notes go out of pitch

2004-01-21 by Peter Andersson

Yes, it's an old production unit alright. I've checked the wires 
between the 366 and the 396. It seems ok, the solder joints too.

Can you tell me which major components are actually involved in the 
lin/log conversion/tuning? I've been told to "check" the key voltage 
selector chip, the DAC and the S/H capacitors as well as something 
called an expo converter. (I don't understand half of this stuff to 
be honest - I know you're not surprised. I'm learning, though... 
quickly!). These are some of the key components of the 366 as far as 
I understand. Do they handle the conversion/tuning you're refering 
to? I thought I'd start out by replacing the S/H capacitors. The 
cheapest and easiest operation to start with, I thought. However, I 
haven't even been able to locate them. It's nearly impossibe to read 
the numbers on the 366 schematics I got off the Old Crow web site. 
(Man what a fantastic resource his site is, btw!).

Again, thanks for helping!

--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
<jo.synth@c...> wrote:
>  From what you tell I would say it is a problem on the KLM-366, in
> the log/lin conversion/tuning section.
> Or maybe you have one of the rare "old production" units. Is there
> a small add-on board "KLM-396" to the KLM-366?
> It could be a lose wire (if "old production") and/or a bad solder
> joint.
> I can see that you are located in Sweden; maybe you ask Ricard
> ( http://home.swipnet.se/ricard2/p6index.html ) for technical help.
> 
> 
> Peter Andersson wrote:
> 
> > Actually, tones are quite stable even during the first 20 
minutes, but
> > the synth is not in tune generally. Also, an octave is a quite 
stable
> > major 7 interval for the first 20 minutes, until suddenly, the 
synth
> > goes into tune and then the octave is correct as well. I'll check
> > tonight if a single generated tone changes a lot during the 
first 10
> > sec.
> > 
> > All six voices are affected. If I play a chord when it suddenly 
slides
> > out of pitch, all notes follow. It actually sounds like I'm 
turning
> > the pitch wheel. (I disconnected the pitch wheel, btw, just to 
be sure
> > it wasn't playing tricks on me).
> > 
> > It is not related to the MG setting and I've played around with 
all
> > three - VCA, VCF and VCO. I'm quite sure it's not affected by the
> > waveform setting either (whether I use a saw or a pulse) but I'll
> > double check that tonight. The PWM setting does not make any
> > difference.
> > 
> > Does this give you any clues? Thanks for helping!
> > 
> > 
> > --- In PolySix@yahoogroups.com, Johannes Hausensteiner 
<jo.synth@c...>
> > wrote:
> > 
> >>It is not normal that it takes 20 miuntes to tune up. Usually it
> >>takes about 10sec to tune and then it is quite stable.
> >>Check the following: hold a key down when switching power on. The
> >>generated note should change quite a lot until it stabilizes 
after
> >>a few secs.
> >>Are all six voice affected? Is the effect related to the MG 
setting
> >>(VCA/VCF/VCO)? Is it related to PWM setting?
> >>
> >>
> >>Peter Andersson wrote:
> >>
> >>
> >>>Hi all,
> >>>
> >>>I'm the proud new owner of a Polysix. I love it! Can't take my
> > 
> > hands 
> > 
> >>>off those knobs - the filters are just great! But I'm having a 
> >>>problem with it and I'm hoping someone can tell me what it's
> > 
> > about 
> > 
> >>>and maybe even what can be done...
> >>>
> >>>After I've played the synth for a while, notes start to go out 
of 
> >>>pitch every now and then. It happens randomly every 10-30 sec or
> > 
> > so. 
> > 
> >>>The notes go off pitch with a note or so and always jump or 
slide 
> >>>back to the original pitch again within half a second.
> >>>
> >>>At first I thought it was some filter setting of mine that 
caused 
Show quoted textHide quoted text
> >>>it, but as it turns out I get this no matter how the Poly6 is 
> >>>programmed (or if I use a preset or a fresh "manual" sound). (By
> > 
> > the 
> > 
> >>>way, it takes about 20 minutes for the unit to get in perfect
> > 
> > tune 
> > 
> >>>after a cold start. Don't know if that's normal or if it's
> > 
> > related 
> > 
> >>>to this problem in any way).
> >>>
> >>>I'd be truly grateful for any help!
> >>>
> >>>Peter
> >>>
> >>>
> >>>
> >>>
> >>>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/ 
> > 
> > 
> > 
> >

Re: [PolySix] Re: Notes go out of pitch

2004-01-23 by Johannes Hausensteiner

The hold capacitors are C56 in unit0..5. But I do not think that it
is the hold capacitors very likey. If it were, not all six voices
would be affected equally. No, it must be something common. If it
is not the wires to/from KLM-396, then the "expo converter" is my
no.1 candidate. KLM-396 seems to be a part of it. The KBD works
logarithmically; that is going up a certain number of keys (e.g.
12 for one octave) multiplies the frequency of the generated note
by a certain factor (times 2 in case of an octave). So the KBD CV
logarithmic by its nature, whereas the oscillators work linear;
that is, the generated frequency changes linearly with the control
voltage (e.g 1V gives 1000Hz, 2V give 2000Hz, 3V give 3000Hz, etc.).
These two schemes are not compatible to each other but it is possible
(and necessary) to convert from one to the other. When converting
from logarithmic to linear you have to do the opposite of logarithm
which is exponential function. It happens that diodes and transistors
have exponential transfer curves, so they can be used for this
purpose. But the exponential function is extrem sensitive to small
variations; a small variation of the input causes a big change at
the output. Furthermore the human ear is very sensitive to changes
in pitch. This means that there must be taken special measures that
the whole thing does not run out of tune.
The expo converter in the Polysix is made of IC17, 18, and 19, Q12
(the expo component), PC-1 (kind of an opto-coupling device), Q3,
and surrounding components. In case of "old production" units
KLM-396 belong to this circuitry, too. Polysix has 6 voices but
the analog (de)multiplexers for the CV have 8 inputs/outputs. The
additional 2 inputs/outputs are used for some kind of calibrating
the exp. amplifier and thus stabilizing tuning of the instrument.
I am not 100% sure how this works as the CPU never measures any
value and therefore cannot adjust to changing values. From what I
can see from the code there is always the value 0 ouput to "voices"
6 and 7.

According to what you tell, it may be a thermal problem. So I would
carefully check all solder points and try to heat up / cool down
the PCB in the area where these components are located. With cooling
spray you may identify a faulty component.

Johannes


Peter Andersson wrote:
Show quoted textHide quoted text
> Yes, it's an old production unit alright. I've checked the wires 
> between the 366 and the 396. It seems ok, the solder joints too.
> 
> Can you tell me which major components are actually involved in the 
> lin/log conversion/tuning? I've been told to "check" the key voltage 
> selector chip, the DAC and the S/H capacitors as well as something 
> called an expo converter. (I don't understand half of this stuff to 
> be honest - I know you're not surprised. I'm learning, though... 
> quickly!). These are some of the key components of the 366 as far as 
> I understand. Do they handle the conversion/tuning you're refering 
> to? I thought I'd start out by replacing the S/H capacitors. The 
> cheapest and easiest operation to start with, I thought. However, I 
> haven't even been able to locate them. It's nearly impossibe to read 
> the numbers on the 366 schematics I got off the Old Crow web site. 
> (Man what a fantastic resource his site is, btw!).
> 
> Again, thanks for helping!
> 
> --- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> <jo.synth@c...> wrote:
> 
>> From what you tell I would say it is a problem on the KLM-366, in
>>the log/lin conversion/tuning section.
>>Or maybe you have one of the rare "old production" units. Is there
>>a small add-on board "KLM-396" to the KLM-366?
>>It could be a lose wire (if "old production") and/or a bad solder
>>joint.
>>I can see that you are located in Sweden; maybe you ask Ricard
>>( http://home.swipnet.se/ricard2/p6index.html ) for technical help.
>>
>>
>>Peter Andersson wrote:
>>
>>
>>>Actually, tones are quite stable even during the first 20 
> 
> minutes, but
> 
>>>the synth is not in tune generally. Also, an octave is a quite 
> 
> stable
> 
>>>major 7 interval for the first 20 minutes, until suddenly, the 
> 
> synth
> 
>>>goes into tune and then the octave is correct as well. I'll check
>>>tonight if a single generated tone changes a lot during the 
> 
> first 10
> 
>>>sec.
>>>
>>>All six voices are affected. If I play a chord when it suddenly 
> 
> slides
> 
>>>out of pitch, all notes follow. It actually sounds like I'm 
> 
> turning
> 
>>>the pitch wheel. (I disconnected the pitch wheel, btw, just to 
> 
> be sure
> 
>>>it wasn't playing tricks on me).
>>>
>>>It is not related to the MG setting and I've played around with 
> 
> all
> 
>>>three - VCA, VCF and VCO. I'm quite sure it's not affected by the
>>>waveform setting either (whether I use a saw or a pulse) but I'll
>>>double check that tonight. The PWM setting does not make any
>>>difference.
>>>
>>>Does this give you any clues? Thanks for helping!
>>>
>>>
>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> 
> <jo.synth@c...>
> 
>>>wrote:
>>>
>>>
>>>>It is not normal that it takes 20 miuntes to tune up. Usually it
>>>>takes about 10sec to tune and then it is quite stable.
>>>>Check the following: hold a key down when switching power on. The
>>>>generated note should change quite a lot until it stabilizes 
> 
> after
> 
>>>>a few secs.
>>>>Are all six voice affected? Is the effect related to the MG 
> 
> setting
> 
>>>>(VCA/VCF/VCO)? Is it related to PWM setting?
>>>>
>>>>
>>>>Peter Andersson wrote:
>>>>
>>>>
>>>>
>>>>>Hi all,
>>>>>
>>>>>I'm the proud new owner of a Polysix. I love it! Can't take my
>>>
>>>hands 
>>>
>>>
>>>>>off those knobs - the filters are just great! But I'm having a 
>>>>>problem with it and I'm hoping someone can tell me what it's
>>>
>>>about 
>>>
>>>
>>>>>and maybe even what can be done...
>>>>>
>>>>>After I've played the synth for a while, notes start to go out 
> 
> of 
> 
>>>>>pitch every now and then. It happens randomly every 10-30 sec or
>>>
>>>so. 
>>>
>>>
>>>>>The notes go off pitch with a note or so and always jump or 
> 
> slide 
> 
>>>>>back to the original pitch again within half a second.
>>>>>
>>>>>At first I thought it was some filter setting of mine that 
> 
> caused 
> 
>>>>>it, but as it turns out I get this no matter how the Poly6 is 
>>>>>programmed (or if I use a preset or a fresh "manual" sound). (By
>>>
>>>the 
>>>
>>>
>>>>>way, it takes about 20 minutes for the unit to get in perfect
>>>
>>>tune 
>>>
>>>
>>>>>after a cold start. Don't know if that's normal or if it's
>>>
>>>related 
>>>
>>>
>>>>>to this problem in any way).
>>>>>
>>>>>I'd be truly grateful for any help!
>>>>>
>>>>>Peter
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>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/ 
> 
> 
> 
>

Re: Notes go out of pitch

2004-01-24 by Peter Andersson

Wow, that's very useful info! Thanks Johannes!

The control voltage must be crucial for the expo conversion to work 
properly then. If any of the amplifier circuits would be broken 
(IC17, 18 or 19), could that cause this behaviour do you think, or 
would that just make everything fail "from start"?

Well, speaking of which... The synth no longer tunes up correctly 
after 20 minutes. Now the tuning and the note intervals are screwed 
up period. So whatever needed "warming up" a few days ago seems to 
have failed permanently now.

I just went over the soldering points around the components you 
pointed out and resoldered most of them to be sure. I still get the 
same problem, though, so I guess it's time to start replacing 
components. I'll definitely try testing with cooling spray. Good 
suggestion! 

BTW, it seems I can replace all components in the expo conversion 
circuitry easily except Q12, Q3 and PC-1. Can't seem to find info on 
these anywhere. You wouldn't happen to know of components compatible 
to any of these three, would you?

Peter


--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
<jo.synth@c...> wrote:
> The hold capacitors are C56 in unit0..5. But I do not think that it
> is the hold capacitors very likey. If it were, not all six voices
> would be affected equally. No, it must be something common. If it
> is not the wires to/from KLM-396, then the "expo converter" is my
> no.1 candidate. KLM-396 seems to be a part of it. The KBD works
> logarithmically; that is going up a certain number of keys (e.g.
> 12 for one octave) multiplies the frequency of the generated note
> by a certain factor (times 2 in case of an octave). So the KBD CV
> logarithmic by its nature, whereas the oscillators work linear;
> that is, the generated frequency changes linearly with the control
> voltage (e.g 1V gives 1000Hz, 2V give 2000Hz, 3V give 3000Hz, 
etc.).
> These two schemes are not compatible to each other but it is 
possible
> (and necessary) to convert from one to the other. When converting
> from logarithmic to linear you have to do the opposite of logarithm
> which is exponential function. It happens that diodes and 
transistors
> have exponential transfer curves, so they can be used for this
> purpose. But the exponential function is extrem sensitive to small
> variations; a small variation of the input causes a big change at
> the output. Furthermore the human ear is very sensitive to changes
> in pitch. This means that there must be taken special measures that
> the whole thing does not run out of tune.
> The expo converter in the Polysix is made of IC17, 18, and 19, Q12
> (the expo component), PC-1 (kind of an opto-coupling device), Q3,
> and surrounding components. In case of "old production" units
> KLM-396 belong to this circuitry, too. Polysix has 6 voices but
> the analog (de)multiplexers for the CV have 8 inputs/outputs. The
> additional 2 inputs/outputs are used for some kind of calibrating
> the exp. amplifier and thus stabilizing tuning of the instrument.
> I am not 100% sure how this works as the CPU never measures any
> value and therefore cannot adjust to changing values. From what I
> can see from the code there is always the value 0 ouput to "voices"
> 6 and 7.
> 
> According to what you tell, it may be a thermal problem. So I would
> carefully check all solder points and try to heat up / cool down
> the PCB in the area where these components are located. With 
cooling
> spray you may identify a faulty component.
> 
> Johannes
> 
> 
> Peter Andersson wrote:
> > Yes, it's an old production unit alright. I've checked the wires 
> > between the 366 and the 396. It seems ok, the solder joints too.
> > 
> > Can you tell me which major components are actually involved in 
the 
> > lin/log conversion/tuning? I've been told to "check" the key 
voltage 
> > selector chip, the DAC and the S/H capacitors as well as 
something 
> > called an expo converter. (I don't understand half of this stuff 
to 
> > be honest - I know you're not surprised. I'm learning, though... 
> > quickly!). These are some of the key components of the 366 as 
far as 
> > I understand. Do they handle the conversion/tuning you're 
refering 
> > to? I thought I'd start out by replacing the S/H capacitors. The 
> > cheapest and easiest operation to start with, I thought. 
However, I 
> > haven't even been able to locate them. It's nearly impossibe to 
read 
> > the numbers on the 366 schematics I got off the Old Crow web 
site. 
> > (Man what a fantastic resource his site is, btw!).
> > 
> > Again, thanks for helping!
> > 
> > --- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> > <jo.synth@c...> wrote:
> > 
> >> From what you tell I would say it is a problem on the KLM-366, 
in
> >>the log/lin conversion/tuning section.
> >>Or maybe you have one of the rare "old production" units. Is 
there
> >>a small add-on board "KLM-396" to the KLM-366?
> >>It could be a lose wire (if "old production") and/or a bad solder
> >>joint.
> >>I can see that you are located in Sweden; maybe you ask Ricard
> >>( http://home.swipnet.se/ricard2/p6index.html ) for technical 
help.
> >>
> >>
> >>Peter Andersson wrote:
> >>
> >>
> >>>Actually, tones are quite stable even during the first 20 
> > 
> > minutes, but
> > 
> >>>the synth is not in tune generally. Also, an octave is a quite 
> > 
> > stable
> > 
> >>>major 7 interval for the first 20 minutes, until suddenly, the 
> > 
> > synth
> > 
> >>>goes into tune and then the octave is correct as well. I'll 
check
> >>>tonight if a single generated tone changes a lot during the 
> > 
> > first 10
> > 
> >>>sec.
> >>>
> >>>All six voices are affected. If I play a chord when it suddenly 
> > 
> > slides
> > 
> >>>out of pitch, all notes follow. It actually sounds like I'm 
> > 
> > turning
> > 
> >>>the pitch wheel. (I disconnected the pitch wheel, btw, just to 
> > 
> > be sure
> > 
> >>>it wasn't playing tricks on me).
> >>>
> >>>It is not related to the MG setting and I've played around with 
> > 
> > all
> > 
> >>>three - VCA, VCF and VCO. I'm quite sure it's not affected by 
the
> >>>waveform setting either (whether I use a saw or a pulse) but 
I'll
> >>>double check that tonight. The PWM setting does not make any
> >>>difference.
> >>>
> >>>Does this give you any clues? Thanks for helping!
> >>>
> >>>
> >>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> > 
> > <jo.synth@c...>
> > 
> >>>wrote:
> >>>
> >>>
> >>>>It is not normal that it takes 20 miuntes to tune up. Usually 
it
> >>>>takes about 10sec to tune and then it is quite stable.
> >>>>Check the following: hold a key down when switching power on. 
The
> >>>>generated note should change quite a lot until it stabilizes 
> > 
> > after
> > 
> >>>>a few secs.
> >>>>Are all six voice affected? Is the effect related to the MG 
> > 
> > setting
> > 
> >>>>(VCA/VCF/VCO)? Is it related to PWM setting?
> >>>>
> >>>>
> >>>>Peter Andersson wrote:
> >>>>
> >>>>
> >>>>
> >>>>>Hi all,
> >>>>>
> >>>>>I'm the proud new owner of a Polysix. I love it! Can't take my
> >>>
> >>>hands 
> >>>
> >>>
> >>>>>off those knobs - the filters are just great! But I'm having 
a 
> >>>>>problem with it and I'm hoping someone can tell me what it's
> >>>
> >>>about 
> >>>
> >>>
> >>>>>and maybe even what can be done...
> >>>>>
> >>>>>After I've played the synth for a while, notes start to go 
out 
> > 
> > of 
> > 
> >>>>>pitch every now and then. It happens randomly every 10-30 sec 
or
> >>>
> >>>so. 
> >>>
> >>>
> >>>>>The notes go off pitch with a note or so and always jump or 
> > 
> > slide 
> > 
> >>>>>back to the original pitch again within half a second.
> >>>>>
> >>>>>At first I thought it was some filter setting of mine that 
> > 
> > caused 
> > 
> >>>>>it, but as it turns out I get this no matter how the Poly6 is 
> >>>>>programmed (or if I use a preset or a fresh "manual" sound). 
(By
Show quoted textHide quoted text
> >>>
> >>>the 
> >>>
> >>>
> >>>>>way, it takes about 20 minutes for the unit to get in perfect
> >>>
> >>>tune 
> >>>
> >>>
> >>>>>after a cold start. Don't know if that's normal or if it's
> >>>
> >>>related 
> >>>
> >>>
> >>>>>to this problem in any way).
> >>>>>
> >>>>>I'd be truly grateful for any help!
> >>>>>
> >>>>>Peter
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>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/ 
> > 
> > 
> > 
> >

Re: [PolySix] Re: Notes go out of pitch

2004-01-24 by Johannes Hausensteiner

I read from the schematic:
* Q12 is a dual npn transistor, common emitter.
   The used type is 2SC1583.
   I found a company D\ufffdnberg Electronics, who does sell this
   component, by entering "2sc1583" into Google

* Q3 is a standard (Japanese) pnp small signal transistor,
   type 2SA733. D\ufffdnberg also do have this one or you can take
   a BC557 as a substitute. But be careful, the pinout is
   different:
                  2SA733          BC557
                   B-C-E          E-B-C

* PC-1 seems to be a Korg custom component. Doesnt it have a
   black rubber tube on it? It is drawn in the schematics as
   an LED optically coupled to an LDR. Hm.
   Maybe someone of the list has a spare?

Johannes



Peter Andersson wrote:
Show quoted textHide quoted text
> Wow, that's very useful info! Thanks Johannes!
> 
> The control voltage must be crucial for the expo conversion to work 
> properly then. If any of the amplifier circuits would be broken 
> (IC17, 18 or 19), could that cause this behaviour do you think, or 
> would that just make everything fail "from start"?
> 
> Well, speaking of which... The synth no longer tunes up correctly 
> after 20 minutes. Now the tuning and the note intervals are screwed 
> up period. So whatever needed "warming up" a few days ago seems to 
> have failed permanently now.
> 
> I just went over the soldering points around the components you 
> pointed out and resoldered most of them to be sure. I still get the 
> same problem, though, so I guess it's time to start replacing 
> components. I'll definitely try testing with cooling spray. Good 
> suggestion! 
> 
> BTW, it seems I can replace all components in the expo conversion 
> circuitry easily except Q12, Q3 and PC-1. Can't seem to find info on 
> these anywhere. You wouldn't happen to know of components compatible 
> to any of these three, would you?
> 
> Peter
> 
> 
> --- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> <jo.synth@c...> wrote:
> 
>>The hold capacitors are C56 in unit0..5. But I do not think that it
>>is the hold capacitors very likey. If it were, not all six voices
>>would be affected equally. No, it must be something common. If it
>>is not the wires to/from KLM-396, then the "expo converter" is my
>>no.1 candidate. KLM-396 seems to be a part of it. The KBD works
>>logarithmically; that is going up a certain number of keys (e.g.
>>12 for one octave) multiplies the frequency of the generated note
>>by a certain factor (times 2 in case of an octave). So the KBD CV
>>logarithmic by its nature, whereas the oscillators work linear;
>>that is, the generated frequency changes linearly with the control
>>voltage (e.g 1V gives 1000Hz, 2V give 2000Hz, 3V give 3000Hz, 
> 
> etc.).
> 
>>These two schemes are not compatible to each other but it is 
> 
> possible
> 
>>(and necessary) to convert from one to the other. When converting
>>from logarithmic to linear you have to do the opposite of logarithm
>>which is exponential function. It happens that diodes and 
> 
> transistors
> 
>>have exponential transfer curves, so they can be used for this
>>purpose. But the exponential function is extrem sensitive to small
>>variations; a small variation of the input causes a big change at
>>the output. Furthermore the human ear is very sensitive to changes
>>in pitch. This means that there must be taken special measures that
>>the whole thing does not run out of tune.
>>The expo converter in the Polysix is made of IC17, 18, and 19, Q12
>>(the expo component), PC-1 (kind of an opto-coupling device), Q3,
>>and surrounding components. In case of "old production" units
>>KLM-396 belong to this circuitry, too. Polysix has 6 voices but
>>the analog (de)multiplexers for the CV have 8 inputs/outputs. The
>>additional 2 inputs/outputs are used for some kind of calibrating
>>the exp. amplifier and thus stabilizing tuning of the instrument.
>>I am not 100% sure how this works as the CPU never measures any
>>value and therefore cannot adjust to changing values. From what I
>>can see from the code there is always the value 0 ouput to "voices"
>>6 and 7.
>>
>>According to what you tell, it may be a thermal problem. So I would
>>carefully check all solder points and try to heat up / cool down
>>the PCB in the area where these components are located. With 
> 
> cooling
> 
>>spray you may identify a faulty component.
>>
>>Johannes
>>
>>
>>Peter Andersson wrote:
>>
>>>Yes, it's an old production unit alright. I've checked the wires 
>>>between the 366 and the 396. It seems ok, the solder joints too.
>>>
>>>Can you tell me which major components are actually involved in 
> 
> the 
> 
>>>lin/log conversion/tuning? I've been told to "check" the key 
> 
> voltage 
> 
>>>selector chip, the DAC and the S/H capacitors as well as 
> 
> something 
> 
>>>called an expo converter. (I don't understand half of this stuff 
> 
> to 
> 
>>>be honest - I know you're not surprised. I'm learning, though... 
>>>quickly!). These are some of the key components of the 366 as 
> 
> far as 
> 
>>>I understand. Do they handle the conversion/tuning you're 
> 
> refering 
> 
>>>to? I thought I'd start out by replacing the S/H capacitors. The 
>>>cheapest and easiest operation to start with, I thought. 
> 
> However, I 
> 
>>>haven't even been able to locate them. It's nearly impossibe to 
> 
> read 
> 
>>>the numbers on the 366 schematics I got off the Old Crow web 
> 
> site. 
> 
>>>(Man what a fantastic resource his site is, btw!).
>>>
>>>Again, thanks for helping!
>>>
>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
>>><jo.synth@c...> wrote:
>>>
>>>
>>>>From what you tell I would say it is a problem on the KLM-366, 
> 
> in
> 
>>>>the log/lin conversion/tuning section.
>>>>Or maybe you have one of the rare "old production" units. Is 
> 
> there
> 
>>>>a small add-on board "KLM-396" to the KLM-366?
>>>>It could be a lose wire (if "old production") and/or a bad solder
>>>>joint.
>>>>I can see that you are located in Sweden; maybe you ask Ricard
>>>>( http://home.swipnet.se/ricard2/p6index.html ) for technical 
> 
> help.
> 
>>>>
>>>>Peter Andersson wrote:
>>>>
>>>>
>>>>
>>>>>Actually, tones are quite stable even during the first 20 
>>>
>>>minutes, but
>>>
>>>
>>>>>the synth is not in tune generally. Also, an octave is a quite 
>>>
>>>stable
>>>
>>>
>>>>>major 7 interval for the first 20 minutes, until suddenly, the 
>>>
>>>synth
>>>
>>>
>>>>>goes into tune and then the octave is correct as well. I'll 
> 
> check
> 
>>>>>tonight if a single generated tone changes a lot during the 
>>>
>>>first 10
>>>
>>>
>>>>>sec.
>>>>>
>>>>>All six voices are affected. If I play a chord when it suddenly 
>>>
>>>slides
>>>
>>>
>>>>>out of pitch, all notes follow. It actually sounds like I'm 
>>>
>>>turning
>>>
>>>
>>>>>the pitch wheel. (I disconnected the pitch wheel, btw, just to 
>>>
>>>be sure
>>>
>>>
>>>>>it wasn't playing tricks on me).
>>>>>
>>>>>It is not related to the MG setting and I've played around with 
>>>
>>>all
>>>
>>>
>>>>>three - VCA, VCF and VCO. I'm quite sure it's not affected by 
> 
> the
> 
>>>>>waveform setting either (whether I use a saw or a pulse) but 
> 
> I'll
> 
>>>>>double check that tonight. The PWM setting does not make any
>>>>>difference.
>>>>>
>>>>>Does this give you any clues? Thanks for helping!
>>>>>
>>>>>
>>>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
>>>
>>><jo.synth@c...>
>>>
>>>>>wrote:
>>>>>
>>>>>
>>>>>
>>>>>>It is not normal that it takes 20 miuntes to tune up. Usually 
> 
> it
> 
>>>>>>takes about 10sec to tune and then it is quite stable.
>>>>>>Check the following: hold a key down when switching power on. 
> 
> The
> 
>>>>>>generated note should change quite a lot until it stabilizes 
>>>
>>>after
>>>
>>>
>>>>>>a few secs.
>>>>>>Are all six voice affected? Is the effect related to the MG 
>>>
>>>setting
>>>
>>>
>>>>>>(VCA/VCF/VCO)? Is it related to PWM setting?
>>>>>>
>>>>>>
>>>>>>Peter Andersson wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>>Hi all,
>>>>>>>
>>>>>>>I'm the proud new owner of a Polysix. I love it! Can't take my
>>>>>
>>>>>hands 
>>>>>
>>>>>
>>>>>
>>>>>>>off those knobs - the filters are just great! But I'm having 
> 
> a 
> 
>>>>>>>problem with it and I'm hoping someone can tell me what it's
>>>>>
>>>>>about 
>>>>>
>>>>>
>>>>>
>>>>>>>and maybe even what can be done...
>>>>>>>
>>>>>>>After I've played the synth for a while, notes start to go 
> 
> out 
> 
>>>of 
>>>
>>>
>>>>>>>pitch every now and then. It happens randomly every 10-30 sec 
> 
> or
> 
>>>>>so. 
>>>>>
>>>>>
>>>>>
>>>>>>>The notes go off pitch with a note or so and always jump or 
>>>
>>>slide 
>>>
>>>
>>>>>>>back to the original pitch again within half a second.
>>>>>>>
>>>>>>>At first I thought it was some filter setting of mine that 
>>>
>>>caused 
>>>
>>>
>>>>>>>it, but as it turns out I get this no matter how the Poly6 is 
>>>>>>>programmed (or if I use a preset or a fresh "manual" sound). 
> 
> (By
> 
>>>>>the 
>>>>>
>>>>>
>>>>>
>>>>>>>way, it takes about 20 minutes for the unit to get in perfect
>>>>>
>>>>>tune 
>>>>>
>>>>>
>>>>>
>>>>>>>after a cold start. Don't know if that's normal or if it's
>>>>>
>>>>>related 
>>>>>
>>>>>
>>>>>
>>>>>>>to this problem in any way).
>>>>>>>
>>>>>>>I'd be truly grateful for any help!
>>>>>>>
>>>>>>>Peter
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>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/ 
>>>
>>>
>>>
>>>
> 
> 
> 
> 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/ 
> 
> 
> 
>

Re: Notes go out of pitch

2004-01-25 by Peter Andersson

You're right, searching for "2SC1583" does give me a bunch of 
interesting matches. No seller in Sweden but there are shops in 
Germany, for example, selling both that and the 2SA733. I'll ask a 
friend to get them and post them to me. Like you say, the opto 
resistor (PC-1) could be tough to get hold of, though. I'll start by 
replacing the transistors anyway and see if that does anything. Oh, 
and what about those amplifier ICs? Is that a long shot you think? 

Peter

--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
<jo.synth@c...> wrote:
> I read from the schematic:
> * Q12 is a dual npn transistor, common emitter.
>    The used type is 2SC1583.
>    I found a company Dönberg Electronics, who does sell this
>    component, by entering "2sc1583" into Google
> 
> * Q3 is a standard (Japanese) pnp small signal transistor,
>    type 2SA733. Dönberg also do have this one or you can take
>    a BC557 as a substitute. But be careful, the pinout is
>    different:
>                   2SA733          BC557
>                    B-C-E          E-B-C
> 
> * PC-1 seems to be a Korg custom component. Doesnt it have a
>    black rubber tube on it? It is drawn in the schematics as
>    an LED optically coupled to an LDR. Hm.
>    Maybe someone of the list has a spare?
> 
> Johannes
> 
> 
> 
> Peter Andersson wrote:
> > Wow, that's very useful info! Thanks Johannes!
> > 
> > The control voltage must be crucial for the expo conversion to 
work 
> > properly then. If any of the amplifier circuits would be broken 
> > (IC17, 18 or 19), could that cause this behaviour do you think, 
or 
> > would that just make everything fail "from start"?
> > 
> > Well, speaking of which... The synth no longer tunes up 
correctly 
> > after 20 minutes. Now the tuning and the note intervals are 
screwed 
> > up period. So whatever needed "warming up" a few days ago seems 
to 
> > have failed permanently now.
> > 
> > I just went over the soldering points around the components you 
> > pointed out and resoldered most of them to be sure. I still get 
the 
> > same problem, though, so I guess it's time to start replacing 
> > components. I'll definitely try testing with cooling spray. Good 
> > suggestion! 
> > 
> > BTW, it seems I can replace all components in the expo 
conversion 
> > circuitry easily except Q12, Q3 and PC-1. Can't seem to find 
info on 
> > these anywhere. You wouldn't happen to know of components 
compatible 
> > to any of these three, would you?
> > 
> > Peter
> > 
> > 
> > --- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> > <jo.synth@c...> wrote:
> > 
> >>The hold capacitors are C56 in unit0..5. But I do not think that 
it
> >>is the hold capacitors very likey. If it were, not all six voices
> >>would be affected equally. No, it must be something common. If it
> >>is not the wires to/from KLM-396, then the "expo converter" is my
> >>no.1 candidate. KLM-396 seems to be a part of it. The KBD works
> >>logarithmically; that is going up a certain number of keys (e.g.
> >>12 for one octave) multiplies the frequency of the generated note
> >>by a certain factor (times 2 in case of an octave). So the KBD CV
> >>logarithmic by its nature, whereas the oscillators work linear;
> >>that is, the generated frequency changes linearly with the 
control
> >>voltage (e.g 1V gives 1000Hz, 2V give 2000Hz, 3V give 3000Hz, 
> > 
> > etc.).
> > 
> >>These two schemes are not compatible to each other but it is 
> > 
> > possible
> > 
> >>(and necessary) to convert from one to the other. When converting
> >>from logarithmic to linear you have to do the opposite of 
logarithm
> >>which is exponential function. It happens that diodes and 
> > 
> > transistors
> > 
> >>have exponential transfer curves, so they can be used for this
> >>purpose. But the exponential function is extrem sensitive to 
small
> >>variations; a small variation of the input causes a big change at
> >>the output. Furthermore the human ear is very sensitive to 
changes
> >>in pitch. This means that there must be taken special measures 
that
> >>the whole thing does not run out of tune.
> >>The expo converter in the Polysix is made of IC17, 18, and 19, 
Q12
> >>(the expo component), PC-1 (kind of an opto-coupling device), Q3,
> >>and surrounding components. In case of "old production" units
> >>KLM-396 belong to this circuitry, too. Polysix has 6 voices but
> >>the analog (de)multiplexers for the CV have 8 inputs/outputs. The
> >>additional 2 inputs/outputs are used for some kind of calibrating
> >>the exp. amplifier and thus stabilizing tuning of the instrument.
> >>I am not 100% sure how this works as the CPU never measures any
> >>value and therefore cannot adjust to changing values. From what I
> >>can see from the code there is always the value 0 ouput 
to "voices"
> >>6 and 7.
> >>
> >>According to what you tell, it may be a thermal problem. So I 
would
> >>carefully check all solder points and try to heat up / cool down
> >>the PCB in the area where these components are located. With 
> > 
> > cooling
> > 
> >>spray you may identify a faulty component.
> >>
> >>Johannes
> >>
> >>
> >>Peter Andersson wrote:
> >>
> >>>Yes, it's an old production unit alright. I've checked the 
wires 
> >>>between the 366 and the 396. It seems ok, the solder joints too.
> >>>
> >>>Can you tell me which major components are actually involved in 
> > 
> > the 
> > 
> >>>lin/log conversion/tuning? I've been told to "check" the key 
> > 
> > voltage 
> > 
> >>>selector chip, the DAC and the S/H capacitors as well as 
> > 
> > something 
> > 
> >>>called an expo converter. (I don't understand half of this 
stuff 
> > 
> > to 
> > 
> >>>be honest - I know you're not surprised. I'm learning, 
though... 
> >>>quickly!). These are some of the key components of the 366 as 
> > 
> > far as 
> > 
> >>>I understand. Do they handle the conversion/tuning you're 
> > 
> > refering 
> > 
> >>>to? I thought I'd start out by replacing the S/H capacitors. 
The 
> >>>cheapest and easiest operation to start with, I thought. 
> > 
> > However, I 
> > 
> >>>haven't even been able to locate them. It's nearly impossibe to 
> > 
> > read 
> > 
> >>>the numbers on the 366 schematics I got off the Old Crow web 
> > 
> > site. 
> > 
> >>>(Man what a fantastic resource his site is, btw!).
> >>>
> >>>Again, thanks for helping!
> >>>
> >>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> >>><jo.synth@c...> wrote:
> >>>
> >>>
> >>>>From what you tell I would say it is a problem on the KLM-366, 
> > 
> > in
> > 
> >>>>the log/lin conversion/tuning section.
> >>>>Or maybe you have one of the rare "old production" units. Is 
> > 
> > there
> > 
> >>>>a small add-on board "KLM-396" to the KLM-366?
> >>>>It could be a lose wire (if "old production") and/or a bad 
solder
> >>>>joint.
> >>>>I can see that you are located in Sweden; maybe you ask Ricard
> >>>>( http://home.swipnet.se/ricard2/p6index.html ) for technical 
> > 
> > help.
> > 
> >>>>
> >>>>Peter Andersson wrote:
> >>>>
> >>>>
> >>>>
> >>>>>Actually, tones are quite stable even during the first 20 
> >>>
> >>>minutes, but
> >>>
> >>>
> >>>>>the synth is not in tune generally. Also, an octave is a 
quite 
> >>>
> >>>stable
> >>>
> >>>
> >>>>>major 7 interval for the first 20 minutes, until suddenly, 
the 
> >>>
> >>>synth
> >>>
> >>>
> >>>>>goes into tune and then the octave is correct as well. I'll 
> > 
> > check
> > 
> >>>>>tonight if a single generated tone changes a lot during the 
> >>>
> >>>first 10
> >>>
> >>>
> >>>>>sec.
> >>>>>
> >>>>>All six voices are affected. If I play a chord when it 
suddenly 
> >>>
> >>>slides
> >>>
> >>>
> >>>>>out of pitch, all notes follow. It actually sounds like I'm 
> >>>
> >>>turning
> >>>
> >>>
> >>>>>the pitch wheel. (I disconnected the pitch wheel, btw, just 
to 
> >>>
> >>>be sure
> >>>
> >>>
> >>>>>it wasn't playing tricks on me).
> >>>>>
> >>>>>It is not related to the MG setting and I've played around 
with 
> >>>
> >>>all
> >>>
> >>>
> >>>>>three - VCA, VCF and VCO. I'm quite sure it's not affected by 
> > 
> > the
> > 
> >>>>>waveform setting either (whether I use a saw or a pulse) but 
> > 
> > I'll
> > 
> >>>>>double check that tonight. The PWM setting does not make any
> >>>>>difference.
> >>>>>
> >>>>>Does this give you any clues? Thanks for helping!
> >>>>>
> >>>>>
> >>>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> >>>
> >>><jo.synth@c...>
> >>>
> >>>>>wrote:
> >>>>>
> >>>>>
> >>>>>
> >>>>>>It is not normal that it takes 20 miuntes to tune up. 
Usually 
> > 
> > it
> > 
> >>>>>>takes about 10sec to tune and then it is quite stable.
> >>>>>>Check the following: hold a key down when switching power 
on. 
> > 
> > The
> > 
> >>>>>>generated note should change quite a lot until it stabilizes 
> >>>
> >>>after
> >>>
> >>>
> >>>>>>a few secs.
> >>>>>>Are all six voice affected? Is the effect related to the MG 
> >>>
> >>>setting
> >>>
> >>>
> >>>>>>(VCA/VCF/VCO)? Is it related to PWM setting?
> >>>>>>
> >>>>>>
> >>>>>>Peter Andersson wrote:
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>>Hi all,
> >>>>>>>
> >>>>>>>I'm the proud new owner of a Polysix. I love it! Can't take 
my
> >>>>>
> >>>>>hands 
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>off those knobs - the filters are just great! But I'm 
having 
> > 
> > a 
> > 
> >>>>>>>problem with it and I'm hoping someone can tell me what it's
> >>>>>
> >>>>>about 
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>and maybe even what can be done...
> >>>>>>>
> >>>>>>>After I've played the synth for a while, notes start to go 
> > 
> > out 
> > 
> >>>of 
> >>>
> >>>
> >>>>>>>pitch every now and then. It happens randomly every 10-30 
sec 
> > 
> > or
> > 
> >>>>>so. 
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>The notes go off pitch with a note or so and always jump or 
> >>>
> >>>slide 
> >>>
> >>>
> >>>>>>>back to the original pitch again within half a second.
> >>>>>>>
> >>>>>>>At first I thought it was some filter setting of mine that 
> >>>
> >>>caused 
> >>>
> >>>
> >>>>>>>it, but as it turns out I get this no matter how the Poly6 
is 
> >>>>>>>programmed (or if I use a preset or a fresh "manual" 
sound). 
> > 
> > (By
> > 
> >>>>>the 
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>way, it takes about 20 minutes for the unit to get in 
perfect
Show quoted textHide quoted text
> >>>>>
> >>>>>tune 
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>after a cold start. Don't know if that's normal or if it's
> >>>>>
> >>>>>related 
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>to this problem in any way).
> >>>>>>>
> >>>>>>>I'd be truly grateful for any help!
> >>>>>>>
> >>>>>>>Peter
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>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/ 
> >>>
> >>>
> >>>
> >>>
> > 
> > 
> > 
> > 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/ 
> > 
> > 
> > 
> >

Re: [PolySix] Re: Notes go out of pitch

2004-01-25 by Johannes Hausensteiner

I would not start to replace all components; I would rather try
to find out the faulty one. Heat up the whole area of the PCB
using a hot fan. Then you can selectively cool down single
components with cooling spray. If you start the Arpeggiator
before you can let play the Polysix for its own and hear changes
immediately.

Johannes


Peter Andersson wrote:
Show quoted textHide quoted text
> You're right, searching for "2SC1583" does give me a bunch of 
> interesting matches. No seller in Sweden but there are shops in 
> Germany, for example, selling both that and the 2SA733. I'll ask a 
> friend to get them and post them to me. Like you say, the opto 
> resistor (PC-1) could be tough to get hold of, though. I'll start by 
> replacing the transistors anyway and see if that does anything. Oh, 
> and what about those amplifier ICs? Is that a long shot you think? 
> 
> Peter
> 
> --- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> <jo.synth@c...> wrote:
> 
>>I read from the schematic:
>>* Q12 is a dual npn transistor, common emitter.
>>   The used type is 2SC1583.
>>   I found a company D\ufffdnberg Electronics, who does sell this
>>   component, by entering "2sc1583" into Google
>>
>>* Q3 is a standard (Japanese) pnp small signal transistor,
>>   type 2SA733. D\ufffdnberg also do have this one or you can take
>>   a BC557 as a substitute. But be careful, the pinout is
>>   different:
>>                  2SA733          BC557
>>                   B-C-E          E-B-C
>>
>>* PC-1 seems to be a Korg custom component. Doesnt it have a
>>   black rubber tube on it? It is drawn in the schematics as
>>   an LED optically coupled to an LDR. Hm.
>>   Maybe someone of the list has a spare?
>>
>>Johannes
>>
>>
>>
>>Peter Andersson wrote:
>>
>>>Wow, that's very useful info! Thanks Johannes!
>>>
>>>The control voltage must be crucial for the expo conversion to 
> 
> work 
> 
>>>properly then. If any of the amplifier circuits would be broken 
>>>(IC17, 18 or 19), could that cause this behaviour do you think, 
> 
> or 
> 
>>>would that just make everything fail "from start"?
>>>
>>>Well, speaking of which... The synth no longer tunes up 
> 
> correctly 
> 
>>>after 20 minutes. Now the tuning and the note intervals are 
> 
> screwed 
> 
>>>up period. So whatever needed "warming up" a few days ago seems 
> 
> to 
> 
>>>have failed permanently now.
>>>
>>>I just went over the soldering points around the components you 
>>>pointed out and resoldered most of them to be sure. I still get 
> 
> the 
> 
>>>same problem, though, so I guess it's time to start replacing 
>>>components. I'll definitely try testing with cooling spray. Good 
>>>suggestion! 
>>>
>>>BTW, it seems I can replace all components in the expo 
> 
> conversion 
> 
>>>circuitry easily except Q12, Q3 and PC-1. Can't seem to find 
> 
> info on 
> 
>>>these anywhere. You wouldn't happen to know of components 
> 
> compatible 
> 
>>>to any of these three, would you?
>>>
>>>Peter
>>>
>>>
>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
>>><jo.synth@c...> wrote:
>>>
>>>
>>>>The hold capacitors are C56 in unit0..5. But I do not think that 
> 
> it
> 
>>>>is the hold capacitors very likey. If it were, not all six voices
>>>>would be affected equally. No, it must be something common. If it
>>>>is not the wires to/from KLM-396, then the "expo converter" is my
>>>>no.1 candidate. KLM-396 seems to be a part of it. The KBD works
>>>>logarithmically; that is going up a certain number of keys (e.g.
>>>>12 for one octave) multiplies the frequency of the generated note
>>>>by a certain factor (times 2 in case of an octave). So the KBD CV
>>>>logarithmic by its nature, whereas the oscillators work linear;
>>>>that is, the generated frequency changes linearly with the 
> 
> control
> 
>>>>voltage (e.g 1V gives 1000Hz, 2V give 2000Hz, 3V give 3000Hz, 
>>>
>>>etc.).
>>>
>>>
>>>>These two schemes are not compatible to each other but it is 
>>>
>>>possible
>>>
>>>
>>>>(and necessary) to convert from one to the other. When converting
>>>
>>>>from logarithmic to linear you have to do the opposite of 
> 
> logarithm
> 
>>>>which is exponential function. It happens that diodes and 
>>>
>>>transistors
>>>
>>>
>>>>have exponential transfer curves, so they can be used for this
>>>>purpose. But the exponential function is extrem sensitive to 
> 
> small
> 
>>>>variations; a small variation of the input causes a big change at
>>>>the output. Furthermore the human ear is very sensitive to 
> 
> changes
> 
>>>>in pitch. This means that there must be taken special measures 
> 
> that
> 
>>>>the whole thing does not run out of tune.
>>>>The expo converter in the Polysix is made of IC17, 18, and 19, 
> 
> Q12
> 
>>>>(the expo component), PC-1 (kind of an opto-coupling device), Q3,
>>>>and surrounding components. In case of "old production" units
>>>>KLM-396 belong to this circuitry, too. Polysix has 6 voices but
>>>>the analog (de)multiplexers for the CV have 8 inputs/outputs. The
>>>>additional 2 inputs/outputs are used for some kind of calibrating
>>>>the exp. amplifier and thus stabilizing tuning of the instrument.
>>>>I am not 100% sure how this works as the CPU never measures any
>>>>value and therefore cannot adjust to changing values. From what I
>>>>can see from the code there is always the value 0 ouput 
> 
> to "voices"
> 
>>>>6 and 7.
>>>>
>>>>According to what you tell, it may be a thermal problem. So I 
> 
> would
> 
>>>>carefully check all solder points and try to heat up / cool down
>>>>the PCB in the area where these components are located. With 
>>>
>>>cooling
>>>
>>>
>>>>spray you may identify a faulty component.
>>>>
>>>>Johannes
>>>>
>>>>
>>>>Peter Andersson wrote:
>>>>
>>>>
>>>>>Yes, it's an old production unit alright. I've checked the 
> 
> wires 
> 
>>>>>between the 366 and the 396. It seems ok, the solder joints too.
>>>>>
>>>>>Can you tell me which major components are actually involved in 
>>>
>>>the 
>>>
>>>
>>>>>lin/log conversion/tuning? I've been told to "check" the key 
>>>
>>>voltage 
>>>
>>>
>>>>>selector chip, the DAC and the S/H capacitors as well as 
>>>
>>>something 
>>>
>>>
>>>>>called an expo converter. (I don't understand half of this 
> 
> stuff 
> 
>>>to 
>>>
>>>
>>>>>be honest - I know you're not surprised. I'm learning, 
> 
> though... 
> 
>>>>>quickly!). These are some of the key components of the 366 as 
>>>
>>>far as 
>>>
>>>
>>>>>I understand. Do they handle the conversion/tuning you're 
>>>
>>>refering 
>>>
>>>
>>>>>to? I thought I'd start out by replacing the S/H capacitors. 
> 
> The 
> 
>>>>>cheapest and easiest operation to start with, I thought. 
>>>
>>>However, I 
>>>
>>>
>>>>>haven't even been able to locate them. It's nearly impossibe to 
>>>
>>>read 
>>>
>>>
>>>>>the numbers on the 366 schematics I got off the Old Crow web 
>>>
>>>site. 
>>>
>>>
>>>>>(Man what a fantastic resource his site is, btw!).
>>>>>
>>>>>Again, thanks for helping!
>>>>>
>>>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
>>>>><jo.synth@c...> wrote:
>>>>>
>>>>>
>>>>>>From what you tell I would say it is a problem on the KLM-366, 
>>>
>>>in
>>>
>>>
>>>>>>the log/lin conversion/tuning section.
>>>>>>Or maybe you have one of the rare "old production" units. Is 
>>>
>>>there
>>>
>>>
>>>>>>a small add-on board "KLM-396" to the KLM-366?
>>>>>>It could be a lose wire (if "old production") and/or a bad 
> 
> solder
> 
>>>>>>joint.
>>>>>>I can see that you are located in Sweden; maybe you ask Ricard
>>>>>>( http://home.swipnet.se/ricard2/p6index.html ) for technical 
>>>
>>>help.
>>>
>>>
>>>>>>Peter Andersson wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>>Actually, tones are quite stable even during the first 20 
>>>>>
>>>>>minutes, but
>>>>>
>>>>>
>>>>>
>>>>>>>the synth is not in tune generally. Also, an octave is a 
> 
> quite 
> 
>>>>>stable
>>>>>
>>>>>
>>>>>
>>>>>>>major 7 interval for the first 20 minutes, until suddenly, 
> 
> the 
> 
>>>>>synth
>>>>>
>>>>>
>>>>>
>>>>>>>goes into tune and then the octave is correct as well. I'll 
>>>
>>>check
>>>
>>>
>>>>>>>tonight if a single generated tone changes a lot during the 
>>>>>
>>>>>first 10
>>>>>
>>>>>
>>>>>
>>>>>>>sec.
>>>>>>>
>>>>>>>All six voices are affected. If I play a chord when it 
> 
> suddenly 
> 
>>>>>slides
>>>>>
>>>>>
>>>>>
>>>>>>>out of pitch, all notes follow. It actually sounds like I'm 
>>>>>
>>>>>turning
>>>>>
>>>>>
>>>>>
>>>>>>>the pitch wheel. (I disconnected the pitch wheel, btw, just 
> 
> to 
> 
>>>>>be sure
>>>>>
>>>>>
>>>>>
>>>>>>>it wasn't playing tricks on me).
>>>>>>>
>>>>>>>It is not related to the MG setting and I've played around 
> 
> with 
> 
>>>>>all
>>>>>
>>>>>
>>>>>
>>>>>>>three - VCA, VCF and VCO. I'm quite sure it's not affected by 
>>>
>>>the
>>>
>>>
>>>>>>>waveform setting either (whether I use a saw or a pulse) but 
>>>
>>>I'll
>>>
>>>
>>>>>>>double check that tonight. The PWM setting does not make any
>>>>>>>difference.
>>>>>>>
>>>>>>>Does this give you any clues? Thanks for helping!
>>>>>>>
>>>>>>>
>>>>>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
>>>>>
>>>>><jo.synth@c...>
>>>>>
>>>>>>>wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>It is not normal that it takes 20 miuntes to tune up. 
> 
> Usually 
> 
>>>it
>>>
>>>
>>>>>>>>takes about 10sec to tune and then it is quite stable.
>>>>>>>>Check the following: hold a key down when switching power 
> 
> on. 
> 
>>>The
>>>
>>>
>>>>>>>>generated note should change quite a lot until it stabilizes 
>>>>>
>>>>>after
>>>>>
>>>>>
>>>>>
>>>>>>>>a few secs.
>>>>>>>>Are all six voice affected? Is the effect related to the MG 
>>>>>
>>>>>setting
>>>>>
>>>>>
>>>>>
>>>>>>>>(VCA/VCF/VCO)? Is it related to PWM setting?
>>>>>>>>
>>>>>>>>
>>>>>>>>Peter Andersson wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>>Hi all,
>>>>>>>>>
>>>>>>>>>I'm the proud new owner of a Polysix. I love it! Can't take 
> 
> my
> 
>>>>>>>hands 
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>off those knobs - the filters are just great! But I'm 
> 
> having 
> 
>>>a 
>>>
>>>
>>>>>>>>>problem with it and I'm hoping someone can tell me what it's
>>>>>>>
>>>>>>>about 
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>and maybe even what can be done...
>>>>>>>>>
>>>>>>>>>After I've played the synth for a while, notes start to go 
>>>
>>>out 
>>>
>>>
>>>>>of 
>>>>>
>>>>>
>>>>>
>>>>>>>>>pitch every now and then. It happens randomly every 10-30 
> 
> sec 
> 
>>>or
>>>
>>>
>>>>>>>so. 
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>The notes go off pitch with a note or so and always jump or 
>>>>>
>>>>>slide 
>>>>>
>>>>>
>>>>>
>>>>>>>>>back to the original pitch again within half a second.
>>>>>>>>>
>>>>>>>>>At first I thought it was some filter setting of mine that 
>>>>>
>>>>>caused 
>>>>>
>>>>>
>>>>>
>>>>>>>>>it, but as it turns out I get this no matter how the Poly6 
> 
> is 
> 
>>>>>>>>>programmed (or if I use a preset or a fresh "manual" 
> 
> sound). 
> 
>>>(By
>>>
>>>
>>>>>>>the 
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>way, it takes about 20 minutes for the unit to get in 
> 
> perfect
> 
>>>>>>>tune 
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>after a cold start. Don't know if that's normal or if it's
>>>>>>>
>>>>>>>related 
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>to this problem in any way).
>>>>>>>>>
>>>>>>>>>I'd be truly grateful for any help!
>>>>>>>>>
>>>>>>>>>Peter
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>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/ 
>>>>>
>>>>>
>>>>>
>>>>>
>>>
>>>
>>>
>>>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/ 
> 
> 
> 
>

Re: Notes go out of pitch

2004-01-26 by Peter Andersson

Alright, thanks! I'll get me some cooling spray, then get to work.

 Peter 

--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
<jo.synth@c...> wrote:
> I would not start to replace all components; I would rather try
> to find out the faulty one. Heat up the whole area of the PCB
> using a hot fan. Then you can selectively cool down single
> components with cooling spray. If you start the Arpeggiator
> before you can let play the Polysix for its own and hear changes
> immediately.
> 
> Johannes
> 
> 
> Peter Andersson wrote:
> > You're right, searching for "2SC1583" does give me a bunch of 
> > interesting matches. No seller in Sweden but there are shops in 
> > Germany, for example, selling both that and the 2SA733. I'll ask 
a 
> > friend to get them and post them to me. Like you say, the opto 
> > resistor (PC-1) could be tough to get hold of, though. I'll 
start by 
> > replacing the transistors anyway and see if that does anything. 
Oh, 
> > and what about those amplifier ICs? Is that a long shot you 
think? 
> > 
> > Peter
> > 
> > --- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> > <jo.synth@c...> wrote:
> > 
> >>I read from the schematic:
> >>* Q12 is a dual npn transistor, common emitter.
> >>   The used type is 2SC1583.
> >>   I found a company Dönberg Electronics, who does sell this
> >>   component, by entering "2sc1583" into Google
> >>
> >>* Q3 is a standard (Japanese) pnp small signal transistor,
> >>   type 2SA733. Dönberg also do have this one or you can take
> >>   a BC557 as a substitute. But be careful, the pinout is
> >>   different:
> >>                  2SA733          BC557
> >>                   B-C-E          E-B-C
> >>
> >>* PC-1 seems to be a Korg custom component. Doesnt it have a
> >>   black rubber tube on it? It is drawn in the schematics as
> >>   an LED optically coupled to an LDR. Hm.
> >>   Maybe someone of the list has a spare?
> >>
> >>Johannes
> >>
> >>
> >>
> >>Peter Andersson wrote:
> >>
> >>>Wow, that's very useful info! Thanks Johannes!
> >>>
> >>>The control voltage must be crucial for the expo conversion to 
> > 
> > work 
> > 
> >>>properly then. If any of the amplifier circuits would be broken 
> >>>(IC17, 18 or 19), could that cause this behaviour do you think, 
> > 
> > or 
> > 
> >>>would that just make everything fail "from start"?
> >>>
> >>>Well, speaking of which... The synth no longer tunes up 
> > 
> > correctly 
> > 
> >>>after 20 minutes. Now the tuning and the note intervals are 
> > 
> > screwed 
> > 
> >>>up period. So whatever needed "warming up" a few days ago seems 
> > 
> > to 
> > 
> >>>have failed permanently now.
> >>>
> >>>I just went over the soldering points around the components you 
> >>>pointed out and resoldered most of them to be sure. I still get 
> > 
> > the 
> > 
> >>>same problem, though, so I guess it's time to start replacing 
> >>>components. I'll definitely try testing with cooling spray. 
Good 
> >>>suggestion! 
> >>>
> >>>BTW, it seems I can replace all components in the expo 
> > 
> > conversion 
> > 
> >>>circuitry easily except Q12, Q3 and PC-1. Can't seem to find 
> > 
> > info on 
> > 
> >>>these anywhere. You wouldn't happen to know of components 
> > 
> > compatible 
> > 
> >>>to any of these three, would you?
> >>>
> >>>Peter
> >>>
> >>>
> >>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> >>><jo.synth@c...> wrote:
> >>>
> >>>
> >>>>The hold capacitors are C56 in unit0..5. But I do not think 
that 
> > 
> > it
> > 
> >>>>is the hold capacitors very likey. If it were, not all six 
voices
> >>>>would be affected equally. No, it must be something common. If 
it
> >>>>is not the wires to/from KLM-396, then the "expo converter" is 
my
> >>>>no.1 candidate. KLM-396 seems to be a part of it. The KBD works
> >>>>logarithmically; that is going up a certain number of keys 
(e.g.
> >>>>12 for one octave) multiplies the frequency of the generated 
note
> >>>>by a certain factor (times 2 in case of an octave). So the KBD 
CV
> >>>>logarithmic by its nature, whereas the oscillators work linear;
> >>>>that is, the generated frequency changes linearly with the 
> > 
> > control
> > 
> >>>>voltage (e.g 1V gives 1000Hz, 2V give 2000Hz, 3V give 3000Hz, 
> >>>
> >>>etc.).
> >>>
> >>>
> >>>>These two schemes are not compatible to each other but it is 
> >>>
> >>>possible
> >>>
> >>>
> >>>>(and necessary) to convert from one to the other. When 
converting
> >>>
> >>>>from logarithmic to linear you have to do the opposite of 
> > 
> > logarithm
> > 
> >>>>which is exponential function. It happens that diodes and 
> >>>
> >>>transistors
> >>>
> >>>
> >>>>have exponential transfer curves, so they can be used for this
> >>>>purpose. But the exponential function is extrem sensitive to 
> > 
> > small
> > 
> >>>>variations; a small variation of the input causes a big change 
at
> >>>>the output. Furthermore the human ear is very sensitive to 
> > 
> > changes
> > 
> >>>>in pitch. This means that there must be taken special measures 
> > 
> > that
> > 
> >>>>the whole thing does not run out of tune.
> >>>>The expo converter in the Polysix is made of IC17, 18, and 19, 
> > 
> > Q12
> > 
> >>>>(the expo component), PC-1 (kind of an opto-coupling device), 
Q3,
> >>>>and surrounding components. In case of "old production" units
> >>>>KLM-396 belong to this circuitry, too. Polysix has 6 voices but
> >>>>the analog (de)multiplexers for the CV have 8 inputs/outputs. 
The
> >>>>additional 2 inputs/outputs are used for some kind of 
calibrating
> >>>>the exp. amplifier and thus stabilizing tuning of the 
instrument.
> >>>>I am not 100% sure how this works as the CPU never measures any
> >>>>value and therefore cannot adjust to changing values. From 
what I
> >>>>can see from the code there is always the value 0 ouput 
> > 
> > to "voices"
> > 
> >>>>6 and 7.
> >>>>
> >>>>According to what you tell, it may be a thermal problem. So I 
> > 
> > would
> > 
> >>>>carefully check all solder points and try to heat up / cool 
down
> >>>>the PCB in the area where these components are located. With 
> >>>
> >>>cooling
> >>>
> >>>
> >>>>spray you may identify a faulty component.
> >>>>
> >>>>Johannes
> >>>>
> >>>>
> >>>>Peter Andersson wrote:
> >>>>
> >>>>
> >>>>>Yes, it's an old production unit alright. I've checked the 
> > 
> > wires 
> > 
> >>>>>between the 366 and the 396. It seems ok, the solder joints 
too.
> >>>>>
> >>>>>Can you tell me which major components are actually involved 
in 
> >>>
> >>>the 
> >>>
> >>>
> >>>>>lin/log conversion/tuning? I've been told to "check" the key 
> >>>
> >>>voltage 
> >>>
> >>>
> >>>>>selector chip, the DAC and the S/H capacitors as well as 
> >>>
> >>>something 
> >>>
> >>>
> >>>>>called an expo converter. (I don't understand half of this 
> > 
> > stuff 
> > 
> >>>to 
> >>>
> >>>
> >>>>>be honest - I know you're not surprised. I'm learning, 
> > 
> > though... 
> > 
> >>>>>quickly!). These are some of the key components of the 366 as 
> >>>
> >>>far as 
> >>>
> >>>
> >>>>>I understand. Do they handle the conversion/tuning you're 
> >>>
> >>>refering 
> >>>
> >>>
> >>>>>to? I thought I'd start out by replacing the S/H capacitors. 
> > 
> > The 
> > 
> >>>>>cheapest and easiest operation to start with, I thought. 
> >>>
> >>>However, I 
> >>>
> >>>
> >>>>>haven't even been able to locate them. It's nearly impossibe 
to 
> >>>
> >>>read 
> >>>
> >>>
> >>>>>the numbers on the 366 schematics I got off the Old Crow web 
> >>>
> >>>site. 
> >>>
> >>>
> >>>>>(Man what a fantastic resource his site is, btw!).
> >>>>>
> >>>>>Again, thanks for helping!
> >>>>>
> >>>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> >>>>><jo.synth@c...> wrote:
> >>>>>
> >>>>>
> >>>>>>From what you tell I would say it is a problem on the KLM-
366, 
> >>>
> >>>in
> >>>
> >>>
> >>>>>>the log/lin conversion/tuning section.
> >>>>>>Or maybe you have one of the rare "old production" units. Is 
> >>>
> >>>there
> >>>
> >>>
> >>>>>>a small add-on board "KLM-396" to the KLM-366?
> >>>>>>It could be a lose wire (if "old production") and/or a bad 
> > 
> > solder
> > 
> >>>>>>joint.
> >>>>>>I can see that you are located in Sweden; maybe you ask 
Ricard
> >>>>>>( http://home.swipnet.se/ricard2/p6index.html ) for 
technical 
> >>>
> >>>help.
> >>>
> >>>
> >>>>>>Peter Andersson wrote:
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>>Actually, tones are quite stable even during the first 20 
> >>>>>
> >>>>>minutes, but
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>the synth is not in tune generally. Also, an octave is a 
> > 
> > quite 
> > 
> >>>>>stable
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>major 7 interval for the first 20 minutes, until suddenly, 
> > 
> > the 
> > 
> >>>>>synth
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>goes into tune and then the octave is correct as well. I'll 
> >>>
> >>>check
> >>>
> >>>
> >>>>>>>tonight if a single generated tone changes a lot during the 
> >>>>>
> >>>>>first 10
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>sec.
> >>>>>>>
> >>>>>>>All six voices are affected. If I play a chord when it 
> > 
> > suddenly 
> > 
> >>>>>slides
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>out of pitch, all notes follow. It actually sounds like I'm 
> >>>>>
> >>>>>turning
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>the pitch wheel. (I disconnected the pitch wheel, btw, just 
> > 
> > to 
> > 
> >>>>>be sure
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>it wasn't playing tricks on me).
> >>>>>>>
> >>>>>>>It is not related to the MG setting and I've played around 
> > 
> > with 
> > 
> >>>>>all
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>three - VCA, VCF and VCO. I'm quite sure it's not affected 
by 
> >>>
> >>>the
> >>>
> >>>
> >>>>>>>waveform setting either (whether I use a saw or a pulse) 
but 
> >>>
> >>>I'll
> >>>
> >>>
> >>>>>>>double check that tonight. The PWM setting does not make any
> >>>>>>>difference.
> >>>>>>>
> >>>>>>>Does this give you any clues? Thanks for helping!
> >>>>>>>
> >>>>>>>
> >>>>>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> >>>>>
> >>>>><jo.synth@c...>
> >>>>>
> >>>>>>>wrote:
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>>It is not normal that it takes 20 miuntes to tune up. 
> > 
> > Usually 
> > 
> >>>it
> >>>
> >>>
> >>>>>>>>takes about 10sec to tune and then it is quite stable.
> >>>>>>>>Check the following: hold a key down when switching power 
> > 
> > on. 
> > 
> >>>The
> >>>
> >>>
> >>>>>>>>generated note should change quite a lot until it 
stabilizes 
> >>>>>
> >>>>>after
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>>a few secs.
> >>>>>>>>Are all six voice affected? Is the effect related to the 
MG 
> >>>>>
> >>>>>setting
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>>(VCA/VCF/VCO)? Is it related to PWM setting?
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>Peter Andersson wrote:
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>>Hi all,
> >>>>>>>>>
> >>>>>>>>>I'm the proud new owner of a Polysix. I love it! Can't 
take 
> > 
> > my
> > 
> >>>>>>>hands 
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>>>off those knobs - the filters are just great! But I'm 
> > 
> > having 
> > 
> >>>a 
> >>>
> >>>
> >>>>>>>>>problem with it and I'm hoping someone can tell me what 
it's
> >>>>>>>
> >>>>>>>about 
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>>>and maybe even what can be done...
> >>>>>>>>>
> >>>>>>>>>After I've played the synth for a while, notes start to 
go 
> >>>
> >>>out 
> >>>
> >>>
> >>>>>of 
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>>>pitch every now and then. It happens randomly every 10-30 
> > 
> > sec 
> > 
> >>>or
> >>>
> >>>
> >>>>>>>so. 
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>>>The notes go off pitch with a note or so and always jump 
or 
> >>>>>
> >>>>>slide 
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>>>back to the original pitch again within half a second.
> >>>>>>>>>
> >>>>>>>>>At first I thought it was some filter setting of mine 
that 
> >>>>>
> >>>>>caused 
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>>>it, but as it turns out I get this no matter how the 
Poly6 
> > 
> > is 
> > 
> >>>>>>>>>programmed (or if I use a preset or a fresh "manual" 
> > 
> > sound). 
> > 
> >>>(By
> >>>
> >>>
> >>>>>>>the 
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>>>way, it takes about 20 minutes for the unit to get in 
> > 
> > perfect
> > 
> >>>>>>>tune 
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>>>after a cold start. Don't know if that's normal or if it's
> >>>>>>>
> >>>>>>>related 
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>>>to this problem in any way).
> >>>>>>>>>
> >>>>>>>>>I'd be truly grateful for any help!
> >>>>>>>>>
> >>>>>>>>>Peter
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>PolySix "Digiest" Page: 
http://www.acc.umu.se/~amber/Poly6 
Show quoted textHide quoted text
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>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/ 
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>
> >>>
> >>>
> >>>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/ 
> > 
> > 
> > 
> >

Re: Notes go out of pitch

2004-02-10 by Peter Andersson

Hi,

I wanted to let you know that I've finally managed to repair my 
Precious (Polysix). It was indeed the opto resistor, the PC-1, that 
was faulty. It was suggested to me that I replace the old mysterious 
PC-1 component with a VTL5C3 and change R93 from 4k7 to 1k2 (to get 
the VTL5C3 working properly). I did and then the synth was as good 
as new!

Appearently, the PC-1 is what stabilizes the expo-converter circuit. 
If it's broken, the circuit can't manage to keep the synth in tune 
as the voltages vary (which is especially noticeable during the time 
the machine is warming up).

Thanks for the help!

  Peter

--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
<jo.synth@c...> wrote:
> I would not start to replace all components; I would rather try
> to find out the faulty one. Heat up the whole area of the PCB
> using a hot fan. Then you can selectively cool down single
> components with cooling spray. If you start the Arpeggiator
> before you can let play the Polysix for its own and hear changes
> immediately.
> 
> Johannes
> 
> 
> Peter Andersson wrote:
> > You're right, searching for "2SC1583" does give me a bunch of 
> > interesting matches. No seller in Sweden but there are shops in 
> > Germany, for example, selling both that and the 2SA733. I'll ask 
a 
> > friend to get them and post them to me. Like you say, the opto 
> > resistor (PC-1) could be tough to get hold of, though. I'll 
start by 
> > replacing the transistors anyway and see if that does anything. 
Oh, 
> > and what about those amplifier ICs? Is that a long shot you 
think? 
> > 
> > Peter
> > 
> > --- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> > <jo.synth@c...> wrote:
> > 
> >>I read from the schematic:
> >>* Q12 is a dual npn transistor, common emitter.
> >>   The used type is 2SC1583.
> >>   I found a company Dönberg Electronics, who does sell this
> >>   component, by entering "2sc1583" into Google
> >>
> >>* Q3 is a standard (Japanese) pnp small signal transistor,
> >>   type 2SA733. Dönberg also do have this one or you can take
> >>   a BC557 as a substitute. But be careful, the pinout is
> >>   different:
> >>                  2SA733          BC557
> >>                   B-C-E          E-B-C
> >>
> >>* PC-1 seems to be a Korg custom component. Doesnt it have a
> >>   black rubber tube on it? It is drawn in the schematics as
> >>   an LED optically coupled to an LDR. Hm.
> >>   Maybe someone of the list has a spare?
> >>
> >>Johannes
> >>
> >>
> >>
> >>Peter Andersson wrote:
> >>
> >>>Wow, that's very useful info! Thanks Johannes!
> >>>
> >>>The control voltage must be crucial for the expo conversion to 
> > 
> > work 
> > 
> >>>properly then. If any of the amplifier circuits would be broken 
> >>>(IC17, 18 or 19), could that cause this behaviour do you think, 
> > 
> > or 
> > 
> >>>would that just make everything fail "from start"?
> >>>
> >>>Well, speaking of which... The synth no longer tunes up 
> > 
> > correctly 
> > 
> >>>after 20 minutes. Now the tuning and the note intervals are 
> > 
> > screwed 
> > 
> >>>up period. So whatever needed "warming up" a few days ago seems 
> > 
> > to 
> > 
> >>>have failed permanently now.
> >>>
> >>>I just went over the soldering points around the components you 
> >>>pointed out and resoldered most of them to be sure. I still get 
> > 
> > the 
> > 
> >>>same problem, though, so I guess it's time to start replacing 
> >>>components. I'll definitely try testing with cooling spray. 
Good 
> >>>suggestion! 
> >>>
> >>>BTW, it seems I can replace all components in the expo 
> > 
> > conversion 
> > 
> >>>circuitry easily except Q12, Q3 and PC-1. Can't seem to find 
> > 
> > info on 
> > 
> >>>these anywhere. You wouldn't happen to know of components 
> > 
> > compatible 
> > 
> >>>to any of these three, would you?
> >>>
> >>>Peter
> >>>
> >>>
> >>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> >>><jo.synth@c...> wrote:
> >>>
> >>>
> >>>>The hold capacitors are C56 in unit0..5. But I do not think 
that 
> > 
> > it
> > 
> >>>>is the hold capacitors very likey. If it were, not all six 
voices
> >>>>would be affected equally. No, it must be something common. If 
it
> >>>>is not the wires to/from KLM-396, then the "expo converter" is 
my
> >>>>no.1 candidate. KLM-396 seems to be a part of it. The KBD works
> >>>>logarithmically; that is going up a certain number of keys 
(e.g.
> >>>>12 for one octave) multiplies the frequency of the generated 
note
> >>>>by a certain factor (times 2 in case of an octave). So the KBD 
CV
> >>>>logarithmic by its nature, whereas the oscillators work linear;
> >>>>that is, the generated frequency changes linearly with the 
> > 
> > control
> > 
> >>>>voltage (e.g 1V gives 1000Hz, 2V give 2000Hz, 3V give 3000Hz, 
> >>>
> >>>etc.).
> >>>
> >>>
> >>>>These two schemes are not compatible to each other but it is 
> >>>
> >>>possible
> >>>
> >>>
> >>>>(and necessary) to convert from one to the other. When 
converting
> >>>
> >>>>from logarithmic to linear you have to do the opposite of 
> > 
> > logarithm
> > 
> >>>>which is exponential function. It happens that diodes and 
> >>>
> >>>transistors
> >>>
> >>>
> >>>>have exponential transfer curves, so they can be used for this
> >>>>purpose. But the exponential function is extrem sensitive to 
> > 
> > small
> > 
> >>>>variations; a small variation of the input causes a big change 
at
> >>>>the output. Furthermore the human ear is very sensitive to 
> > 
> > changes
> > 
> >>>>in pitch. This means that there must be taken special measures 
> > 
> > that
> > 
> >>>>the whole thing does not run out of tune.
> >>>>The expo converter in the Polysix is made of IC17, 18, and 19, 
> > 
> > Q12
> > 
> >>>>(the expo component), PC-1 (kind of an opto-coupling device), 
Q3,
> >>>>and surrounding components. In case of "old production" units
> >>>>KLM-396 belong to this circuitry, too. Polysix has 6 voices but
> >>>>the analog (de)multiplexers for the CV have 8 inputs/outputs. 
The
> >>>>additional 2 inputs/outputs are used for some kind of 
calibrating
> >>>>the exp. amplifier and thus stabilizing tuning of the 
instrument.
> >>>>I am not 100% sure how this works as the CPU never measures any
> >>>>value and therefore cannot adjust to changing values. From 
what I
> >>>>can see from the code there is always the value 0 ouput 
> > 
> > to "voices"
> > 
> >>>>6 and 7.
> >>>>
> >>>>According to what you tell, it may be a thermal problem. So I 
> > 
> > would
> > 
> >>>>carefully check all solder points and try to heat up / cool 
down
> >>>>the PCB in the area where these components are located. With 
> >>>
> >>>cooling
> >>>
> >>>
> >>>>spray you may identify a faulty component.
> >>>>
> >>>>Johannes
> >>>>
> >>>>
> >>>>Peter Andersson wrote:
> >>>>
> >>>>
> >>>>>Yes, it's an old production unit alright. I've checked the 
> > 
> > wires 
> > 
> >>>>>between the 366 and the 396. It seems ok, the solder joints 
too.
> >>>>>
> >>>>>Can you tell me which major components are actually involved 
in 
> >>>
> >>>the 
> >>>
> >>>
> >>>>>lin/log conversion/tuning? I've been told to "check" the key 
> >>>
> >>>voltage 
> >>>
> >>>
> >>>>>selector chip, the DAC and the S/H capacitors as well as 
> >>>
> >>>something 
> >>>
> >>>
> >>>>>called an expo converter. (I don't understand half of this 
> > 
> > stuff 
> > 
> >>>to 
> >>>
> >>>
> >>>>>be honest - I know you're not surprised. I'm learning, 
> > 
> > though... 
> > 
> >>>>>quickly!). These are some of the key components of the 366 as 
> >>>
> >>>far as 
> >>>
> >>>
> >>>>>I understand. Do they handle the conversion/tuning you're 
> >>>
> >>>refering 
> >>>
> >>>
> >>>>>to? I thought I'd start out by replacing the S/H capacitors. 
> > 
> > The 
> > 
> >>>>>cheapest and easiest operation to start with, I thought. 
> >>>
> >>>However, I 
> >>>
> >>>
> >>>>>haven't even been able to locate them. It's nearly impossibe 
to 
> >>>
> >>>read 
> >>>
> >>>
> >>>>>the numbers on the 366 schematics I got off the Old Crow web 
> >>>
> >>>site. 
> >>>
> >>>
> >>>>>(Man what a fantastic resource his site is, btw!).
> >>>>>
> >>>>>Again, thanks for helping!
> >>>>>
> >>>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> >>>>><jo.synth@c...> wrote:
> >>>>>
> >>>>>
> >>>>>>From what you tell I would say it is a problem on the KLM-
366, 
> >>>
> >>>in
> >>>
> >>>
> >>>>>>the log/lin conversion/tuning section.
> >>>>>>Or maybe you have one of the rare "old production" units. Is 
> >>>
> >>>there
> >>>
> >>>
> >>>>>>a small add-on board "KLM-396" to the KLM-366?
> >>>>>>It could be a lose wire (if "old production") and/or a bad 
> > 
> > solder
> > 
> >>>>>>joint.
> >>>>>>I can see that you are located in Sweden; maybe you ask 
Ricard
> >>>>>>( http://home.swipnet.se/ricard2/p6index.html ) for 
technical 
> >>>
> >>>help.
> >>>
> >>>
> >>>>>>Peter Andersson wrote:
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>>Actually, tones are quite stable even during the first 20 
> >>>>>
> >>>>>minutes, but
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>the synth is not in tune generally. Also, an octave is a 
> > 
> > quite 
> > 
> >>>>>stable
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>major 7 interval for the first 20 minutes, until suddenly, 
> > 
> > the 
> > 
> >>>>>synth
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>goes into tune and then the octave is correct as well. I'll 
> >>>
> >>>check
> >>>
> >>>
> >>>>>>>tonight if a single generated tone changes a lot during the 
> >>>>>
> >>>>>first 10
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>sec.
> >>>>>>>
> >>>>>>>All six voices are affected. If I play a chord when it 
> > 
> > suddenly 
> > 
> >>>>>slides
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>out of pitch, all notes follow. It actually sounds like I'm 
> >>>>>
> >>>>>turning
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>the pitch wheel. (I disconnected the pitch wheel, btw, just 
> > 
> > to 
> > 
> >>>>>be sure
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>it wasn't playing tricks on me).
> >>>>>>>
> >>>>>>>It is not related to the MG setting and I've played around 
> > 
> > with 
> > 
> >>>>>all
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>three - VCA, VCF and VCO. I'm quite sure it's not affected 
by 
> >>>
> >>>the
> >>>
> >>>
> >>>>>>>waveform setting either (whether I use a saw or a pulse) 
but 
> >>>
> >>>I'll
> >>>
> >>>
> >>>>>>>double check that tonight. The PWM setting does not make any
> >>>>>>>difference.
> >>>>>>>
> >>>>>>>Does this give you any clues? Thanks for helping!
> >>>>>>>
> >>>>>>>
> >>>>>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> >>>>>
> >>>>><jo.synth@c...>
> >>>>>
> >>>>>>>wrote:
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>>It is not normal that it takes 20 miuntes to tune up. 
> > 
> > Usually 
> > 
> >>>it
> >>>
> >>>
> >>>>>>>>takes about 10sec to tune and then it is quite stable.
> >>>>>>>>Check the following: hold a key down when switching power 
> > 
> > on. 
> > 
> >>>The
> >>>
> >>>
> >>>>>>>>generated note should change quite a lot until it 
stabilizes 
> >>>>>
> >>>>>after
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>>a few secs.
> >>>>>>>>Are all six voice affected? Is the effect related to the 
MG 
> >>>>>
> >>>>>setting
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>>(VCA/VCF/VCO)? Is it related to PWM setting?
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>Peter Andersson wrote:
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>>Hi all,
> >>>>>>>>>
> >>>>>>>>>I'm the proud new owner of a Polysix. I love it! Can't 
take 
> > 
> > my
> > 
> >>>>>>>hands 
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>>>off those knobs - the filters are just great! But I'm 
> > 
> > having 
> > 
> >>>a 
> >>>
> >>>
> >>>>>>>>>problem with it and I'm hoping someone can tell me what 
it's
> >>>>>>>
> >>>>>>>about 
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>>>and maybe even what can be done...
> >>>>>>>>>
> >>>>>>>>>After I've played the synth for a while, notes start to 
go 
> >>>
> >>>out 
> >>>
> >>>
> >>>>>of 
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>>>pitch every now and then. It happens randomly every 10-30 
> > 
> > sec 
> > 
> >>>or
> >>>
> >>>
> >>>>>>>so. 
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>>>The notes go off pitch with a note or so and always jump 
or 
> >>>>>
> >>>>>slide 
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>>>back to the original pitch again within half a second.
> >>>>>>>>>
> >>>>>>>>>At first I thought it was some filter setting of mine 
that 
> >>>>>
> >>>>>caused 
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>>>it, but as it turns out I get this no matter how the 
Poly6 
> > 
> > is 
> > 
> >>>>>>>>>programmed (or if I use a preset or a fresh "manual" 
> > 
> > sound). 
> > 
> >>>(By
> >>>
> >>>
> >>>>>>>the 
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>>>way, it takes about 20 minutes for the unit to get in 
> > 
> > perfect
> > 
> >>>>>>>tune 
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>>>after a cold start. Don't know if that's normal or if it's
> >>>>>>>
> >>>>>>>related 
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>>>to this problem in any way).
> >>>>>>>>>
> >>>>>>>>>I'd be truly grateful for any help!
> >>>>>>>>>
> >>>>>>>>>Peter
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>PolySix "Digiest" Page: 
http://www.acc.umu.se/~amber/Poly6 
Show quoted textHide quoted text
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>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/ 
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>
> >>>
> >>>
> >>>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/ 
> > 
> > 
> > 
> >

Re: [PolySix] Re: Notes go out of pitch

2004-02-14 by Johannes Hausensteiner

Hello,

Thank you for the info!

Best regards,

Johannes


Peter Andersson wrote:
Show quoted textHide quoted text
> Hi,
> 
> I wanted to let you know that I've finally managed to repair my 
> Precious (Polysix). It was indeed the opto resistor, the PC-1, that 
> was faulty. It was suggested to me that I replace the old mysterious 
> PC-1 component with a VTL5C3 and change R93 from 4k7 to 1k2 (to get 
> the VTL5C3 working properly). I did and then the synth was as good 
> as new!
> 
> Appearently, the PC-1 is what stabilizes the expo-converter circuit. 
> If it's broken, the circuit can't manage to keep the synth in tune 
> as the voltages vary (which is especially noticeable during the time 
> the machine is warming up).
> 
> Thanks for the help!
> 
>   Peter
> 
> --- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> <jo.synth@c...> wrote:
> 
>>I would not start to replace all components; I would rather try
>>to find out the faulty one. Heat up the whole area of the PCB
>>using a hot fan. Then you can selectively cool down single
>>components with cooling spray. If you start the Arpeggiator
>>before you can let play the Polysix for its own and hear changes
>>immediately.
>>
>>Johannes
>>
>>
>>Peter Andersson wrote:
>>
>>>You're right, searching for "2SC1583" does give me a bunch of 
>>>interesting matches. No seller in Sweden but there are shops in 
>>>Germany, for example, selling both that and the 2SA733. I'll ask 
> 
> a 
> 
>>>friend to get them and post them to me. Like you say, the opto 
>>>resistor (PC-1) could be tough to get hold of, though. I'll 
> 
> start by 
> 
>>>replacing the transistors anyway and see if that does anything. 
> 
> Oh, 
> 
>>>and what about those amplifier ICs? Is that a long shot you 
> 
> think? 
> 
>>>Peter
>>>
>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
>>><jo.synth@c...> wrote:
>>>
>>>
>>>>I read from the schematic:
>>>>* Q12 is a dual npn transistor, common emitter.
>>>>  The used type is 2SC1583.
>>>>  I found a company D\ufffdnberg Electronics, who does sell this
>>>>  component, by entering "2sc1583" into Google
>>>>
>>>>* Q3 is a standard (Japanese) pnp small signal transistor,
>>>>  type 2SA733. D\ufffdnberg also do have this one or you can take
>>>>  a BC557 as a substitute. But be careful, the pinout is
>>>>  different:
>>>>                 2SA733          BC557
>>>>                  B-C-E          E-B-C
>>>>
>>>>* PC-1 seems to be a Korg custom component. Doesnt it have a
>>>>  black rubber tube on it? It is drawn in the schematics as
>>>>  an LED optically coupled to an LDR. Hm.
>>>>  Maybe someone of the list has a spare?
>>>>
>>>>Johannes
>>>>
>>>>
>>>>
>>>>Peter Andersson wrote:
>>>>
>>>>
>>>>>Wow, that's very useful info! Thanks Johannes!
>>>>>
>>>>>The control voltage must be crucial for the expo conversion to 
>>>
>>>work 
>>>
>>>
>>>>>properly then. If any of the amplifier circuits would be broken 
>>>>>(IC17, 18 or 19), could that cause this behaviour do you think, 
>>>
>>>or 
>>>
>>>
>>>>>would that just make everything fail "from start"?
>>>>>
>>>>>Well, speaking of which... The synth no longer tunes up 
>>>
>>>correctly 
>>>
>>>
>>>>>after 20 minutes. Now the tuning and the note intervals are 
>>>
>>>screwed 
>>>
>>>
>>>>>up period. So whatever needed "warming up" a few days ago seems 
>>>
>>>to 
>>>
>>>
>>>>>have failed permanently now.
>>>>>
>>>>>I just went over the soldering points around the components you 
>>>>>pointed out and resoldered most of them to be sure. I still get 
>>>
>>>the 
>>>
>>>
>>>>>same problem, though, so I guess it's time to start replacing 
>>>>>components. I'll definitely try testing with cooling spray. 
> 
> Good 
> 
>>>>>suggestion! 
>>>>>
>>>>>BTW, it seems I can replace all components in the expo 
>>>
>>>conversion 
>>>
>>>
>>>>>circuitry easily except Q12, Q3 and PC-1. Can't seem to find 
>>>
>>>info on 
>>>
>>>
>>>>>these anywhere. You wouldn't happen to know of components 
>>>
>>>compatible 
>>>
>>>
>>>>>to any of these three, would you?
>>>>>
>>>>>Peter
>>>>>
>>>>>
>>>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
>>>>><jo.synth@c...> wrote:
>>>>>
>>>>>
>>>>>
>>>>>>The hold capacitors are C56 in unit0..5. But I do not think 
> 
> that 
> 
>>>it
>>>
>>>
>>>>>>is the hold capacitors very likey. If it were, not all six 
> 
> voices
> 
>>>>>>would be affected equally. No, it must be something common. If 
> 
> it
> 
>>>>>>is not the wires to/from KLM-396, then the "expo converter" is 
> 
> my
> 
>>>>>>no.1 candidate. KLM-396 seems to be a part of it. The KBD works
>>>>>>logarithmically; that is going up a certain number of keys 
> 
> (e.g.
> 
>>>>>>12 for one octave) multiplies the frequency of the generated 
> 
> note
> 
>>>>>>by a certain factor (times 2 in case of an octave). So the KBD 
> 
> CV
> 
>>>>>>logarithmic by its nature, whereas the oscillators work linear;
>>>>>>that is, the generated frequency changes linearly with the 
>>>
>>>control
>>>
>>>
>>>>>>voltage (e.g 1V gives 1000Hz, 2V give 2000Hz, 3V give 3000Hz, 
>>>>>
>>>>>etc.).
>>>>>
>>>>>
>>>>>
>>>>>>These two schemes are not compatible to each other but it is 
>>>>>
>>>>>possible
>>>>>
>>>>>
>>>>>
>>>>>>(and necessary) to convert from one to the other. When 
> 
> converting
> 
>>>>>>from logarithmic to linear you have to do the opposite of 
>>>
>>>logarithm
>>>
>>>
>>>>>>which is exponential function. It happens that diodes and 
>>>>>
>>>>>transistors
>>>>>
>>>>>
>>>>>
>>>>>>have exponential transfer curves, so they can be used for this
>>>>>>purpose. But the exponential function is extrem sensitive to 
>>>
>>>small
>>>
>>>
>>>>>>variations; a small variation of the input causes a big change 
> 
> at
> 
>>>>>>the output. Furthermore the human ear is very sensitive to 
>>>
>>>changes
>>>
>>>
>>>>>>in pitch. This means that there must be taken special measures 
>>>
>>>that
>>>
>>>
>>>>>>the whole thing does not run out of tune.
>>>>>>The expo converter in the Polysix is made of IC17, 18, and 19, 
>>>
>>>Q12
>>>
>>>
>>>>>>(the expo component), PC-1 (kind of an opto-coupling device), 
> 
> Q3,
> 
>>>>>>and surrounding components. In case of "old production" units
>>>>>>KLM-396 belong to this circuitry, too. Polysix has 6 voices but
>>>>>>the analog (de)multiplexers for the CV have 8 inputs/outputs. 
> 
> The
> 
>>>>>>additional 2 inputs/outputs are used for some kind of 
> 
> calibrating
> 
>>>>>>the exp. amplifier and thus stabilizing tuning of the 
> 
> instrument.
> 
>>>>>>I am not 100% sure how this works as the CPU never measures any
>>>>>>value and therefore cannot adjust to changing values. From 
> 
> what I
> 
>>>>>>can see from the code there is always the value 0 ouput 
>>>
>>>to "voices"
>>>
>>>
>>>>>>6 and 7.
>>>>>>
>>>>>>According to what you tell, it may be a thermal problem. So I 
>>>
>>>would
>>>
>>>
>>>>>>carefully check all solder points and try to heat up / cool 
> 
> down
> 
>>>>>>the PCB in the area where these components are located. With 
>>>>>
>>>>>cooling
>>>>>
>>>>>
>>>>>
>>>>>>spray you may identify a faulty component.
>>>>>>
>>>>>>Johannes
>>>>>>
>>>>>>
>>>>>>Peter Andersson wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>>Yes, it's an old production unit alright. I've checked the 
>>>
>>>wires 
>>>
>>>
>>>>>>>between the 366 and the 396. It seems ok, the solder joints 
> 
> too.
> 
>>>>>>>Can you tell me which major components are actually involved 
> 
> in 
> 
>>>>>the 
>>>>>
>>>>>
>>>>>
>>>>>>>lin/log conversion/tuning? I've been told to "check" the key 
>>>>>
>>>>>voltage 
>>>>>
>>>>>
>>>>>
>>>>>>>selector chip, the DAC and the S/H capacitors as well as 
>>>>>
>>>>>something 
>>>>>
>>>>>
>>>>>
>>>>>>>called an expo converter. (I don't understand half of this 
>>>
>>>stuff 
>>>
>>>
>>>>>to 
>>>>>
>>>>>
>>>>>
>>>>>>>be honest - I know you're not surprised. I'm learning, 
>>>
>>>though... 
>>>
>>>
>>>>>>>quickly!). These are some of the key components of the 366 as 
>>>>>
>>>>>far as 
>>>>>
>>>>>
>>>>>
>>>>>>>I understand. Do they handle the conversion/tuning you're 
>>>>>
>>>>>refering 
>>>>>
>>>>>
>>>>>
>>>>>>>to? I thought I'd start out by replacing the S/H capacitors. 
>>>
>>>The 
>>>
>>>
>>>>>>>cheapest and easiest operation to start with, I thought. 
>>>>>
>>>>>However, I 
>>>>>
>>>>>
>>>>>
>>>>>>>haven't even been able to locate them. It's nearly impossibe 
> 
> to 
> 
>>>>>read 
>>>>>
>>>>>
>>>>>
>>>>>>>the numbers on the 366 schematics I got off the Old Crow web 
>>>>>
>>>>>site. 
>>>>>
>>>>>
>>>>>
>>>>>>>(Man what a fantastic resource his site is, btw!).
>>>>>>>
>>>>>>>Again, thanks for helping!
>>>>>>>
>>>>>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
>>>>>>><jo.synth@c...> wrote:
>>>>>>>
>>>>>>>
>>>>>>>>From what you tell I would say it is a problem on the KLM-
> 
> 366, 
> 
>>>>>in
>>>>>
>>>>>
>>>>>
>>>>>>>>the log/lin conversion/tuning section.
>>>>>>>>Or maybe you have one of the rare "old production" units. Is 
>>>>>
>>>>>there
>>>>>
>>>>>
>>>>>
>>>>>>>>a small add-on board "KLM-396" to the KLM-366?
>>>>>>>>It could be a lose wire (if "old production") and/or a bad 
>>>
>>>solder
>>>
>>>
>>>>>>>>joint.
>>>>>>>>I can see that you are located in Sweden; maybe you ask 
> 
> Ricard
> 
>>>>>>>>( http://home.swipnet.se/ricard2/p6index.html ) for 
> 
> technical 
> 
>>>>>help.
>>>>>
>>>>>
>>>>>
>>>>>>>>Peter Andersson wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>>Actually, tones are quite stable even during the first 20 
>>>>>>>
>>>>>>>minutes, but
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>the synth is not in tune generally. Also, an octave is a 
>>>
>>>quite 
>>>
>>>
>>>>>>>stable
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>major 7 interval for the first 20 minutes, until suddenly, 
>>>
>>>the 
>>>
>>>
>>>>>>>synth
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>goes into tune and then the octave is correct as well. I'll 
>>>>>
>>>>>check
>>>>>
>>>>>
>>>>>
>>>>>>>>>tonight if a single generated tone changes a lot during the 
>>>>>>>
>>>>>>>first 10
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>sec.
>>>>>>>>>
>>>>>>>>>All six voices are affected. If I play a chord when it 
>>>
>>>suddenly 
>>>
>>>
>>>>>>>slides
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>out of pitch, all notes follow. It actually sounds like I'm 
>>>>>>>
>>>>>>>turning
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>the pitch wheel. (I disconnected the pitch wheel, btw, just 
>>>
>>>to 
>>>
>>>
>>>>>>>be sure
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>it wasn't playing tricks on me).
>>>>>>>>>
>>>>>>>>>It is not related to the MG setting and I've played around 
>>>
>>>with 
>>>
>>>
>>>>>>>all
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>three - VCA, VCF and VCO. I'm quite sure it's not affected 
> 
> by 
> 
>>>>>the
>>>>>
>>>>>
>>>>>
>>>>>>>>>waveform setting either (whether I use a saw or a pulse) 
> 
> but 
> 
>>>>>I'll
>>>>>
>>>>>
>>>>>
>>>>>>>>>double check that tonight. The PWM setting does not make any
>>>>>>>>>difference.
>>>>>>>>>
>>>>>>>>>Does this give you any clues? Thanks for helping!
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
>>>>>>>
>>>>>>><jo.synth@c...>
>>>>>>>
>>>>>>>>>wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>It is not normal that it takes 20 miuntes to tune up. 
>>>
>>>Usually 
>>>
>>>
>>>>>it
>>>>>
>>>>>
>>>>>
>>>>>>>>>>takes about 10sec to tune and then it is quite stable.
>>>>>>>>>>Check the following: hold a key down when switching power 
>>>
>>>on. 
>>>
>>>
>>>>>The
>>>>>
>>>>>
>>>>>
>>>>>>>>>>generated note should change quite a lot until it 
> 
> stabilizes 
> 
>>>>>>>after
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>>a few secs.
>>>>>>>>>>Are all six voice affected? Is the effect related to the 
> 
> MG 
> 
>>>>>>>setting
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>>(VCA/VCF/VCO)? Is it related to PWM setting?
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>Peter Andersson wrote:
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>>Hi all,
>>>>>>>>>>>
>>>>>>>>>>>I'm the proud new owner of a Polysix. I love it! Can't 
> 
> take 
> 
>>>my
>>>
>>>
>>>>>>>>>hands 
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>off those knobs - the filters are just great! But I'm 
>>>
>>>having 
>>>
>>>
>>>>>a 
>>>>>
>>>>>
>>>>>
>>>>>>>>>>>problem with it and I'm hoping someone can tell me what 
> 
> it's
> 
>>>>>>>>>about 
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>and maybe even what can be done...
>>>>>>>>>>>
>>>>>>>>>>>After I've played the synth for a while, notes start to 
> 
> go 
> 
>>>>>out 
>>>>>
>>>>>
>>>>>
>>>>>>>of 
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>>>pitch every now and then. It happens randomly every 10-30 
>>>
>>>sec 
>>>
>>>
>>>>>or
>>>>>
>>>>>
>>>>>
>>>>>>>>>so. 
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>The notes go off pitch with a note or so and always jump 
> 
> or 
> 
>>>>>>>slide 
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>>>back to the original pitch again within half a second.
>>>>>>>>>>>
>>>>>>>>>>>At first I thought it was some filter setting of mine 
> 
> that 
> 
>>>>>>>caused 
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>>>it, but as it turns out I get this no matter how the 
> 
> Poly6 
> 
>>>is 
>>>
>>>
>>>>>>>>>>>programmed (or if I use a preset or a fresh "manual" 
>>>
>>>sound). 
>>>
>>>
>>>>>(By
>>>>>
>>>>>
>>>>>
>>>>>>>>>the 
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>way, it takes about 20 minutes for the unit to get in 
>>>
>>>perfect
>>>
>>>
>>>>>>>>>tune 
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>after a cold start. Don't know if that's normal or if it's
>>>>>>>>>
>>>>>>>>>related 
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>to this problem in any way).
>>>>>>>>>>>
>>>>>>>>>>>I'd be truly grateful for any help!
>>>>>>>>>>>
>>>>>>>>>>>Peter
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>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/ 
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>
>>>>>
>>>>>
>>>>>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
> 
> 
> 
>  
> 
> 
>

Re: Notes go out of pitch

2006-08-08 by sdlarch1

I'm not familiar with the resistor value notation used here.
What are 4k7 and 1k2?  4.7k?  47k?


--- In PolySix@yahoogroups.com, "Peter Andersson" 
<peter.peppe.andersson@...> wrote:
>
> 
> Hi,
> 
> I wanted to let you know that I've finally managed to repair my 
> Precious (Polysix). It was indeed the opto resistor, the PC-1, that 
> was faulty. It was suggested to me that I replace the old 
mysterious 
> PC-1 component with a VTL5C3 and change R93 from 4k7 to 1k2 (to get 
> the VTL5C3 working properly). I did and then the synth was as good 
> as new!
> 
> Appearently, the PC-1 is what stabilizes the expo-converter 
circuit. 
> If it's broken, the circuit can't manage to keep the synth in tune 
> as the voltages vary (which is especially noticeable during the 
time 
> the machine is warming up).
> 
> Thanks for the help!
> 
>   Peter
> 
> --- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> <jo.synth@c...> wrote:
> > I would not start to replace all components; I would rather try
> > to find out the faulty one. Heat up the whole area of the PCB
> > using a hot fan. Then you can selectively cool down single
> > components with cooling spray. If you start the Arpeggiator
> > before you can let play the Polysix for its own and hear changes
> > immediately.
> > 
> > Johannes
> > 
> > 
> > Peter Andersson wrote:
> > > You're right, searching for "2SC1583" does give me a bunch of 
> > > interesting matches. No seller in Sweden but there are shops in 
> > > Germany, for example, selling both that and the 2SA733. I'll 
ask 
> a 
> > > friend to get them and post them to me. Like you say, the opto 
> > > resistor (PC-1) could be tough to get hold of, though. I'll 
> start by 
> > > replacing the transistors anyway and see if that does anything. 
> Oh, 
> > > and what about those amplifier ICs? Is that a long shot you 
> think? 
> > > 
> > > Peter
> > > 
> > > --- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> > > <jo.synth@c...> wrote:
> > > 
> > >>I read from the schematic:
> > >>* Q12 is a dual npn transistor, common emitter.
> > >>   The used type is 2SC1583.
> > >>   I found a company Dönberg Electronics, who does sell this
> > >>   component, by entering "2sc1583" into Google
> > >>
> > >>* Q3 is a standard (Japanese) pnp small signal transistor,
> > >>   type 2SA733. Dönberg also do have this one or you can take
> > >>   a BC557 as a substitute. But be careful, the pinout is
> > >>   different:
> > >>                  2SA733          BC557
> > >>                   B-C-E          E-B-C
> > >>
> > >>* PC-1 seems to be a Korg custom component. Doesnt it have a
> > >>   black rubber tube on it? It is drawn in the schematics as
> > >>   an LED optically coupled to an LDR. Hm.
> > >>   Maybe someone of the list has a spare?
> > >>
> > >>Johannes
> > >>
> > >>
> > >>
> > >>Peter Andersson wrote:
> > >>
> > >>>Wow, that's very useful info! Thanks Johannes!
> > >>>
> > >>>The control voltage must be crucial for the expo conversion to 
> > > 
> > > work 
> > > 
> > >>>properly then. If any of the amplifier circuits would be 
broken 
> > >>>(IC17, 18 or 19), could that cause this behaviour do you 
think, 
> > > 
> > > or 
> > > 
> > >>>would that just make everything fail "from start"?
> > >>>
> > >>>Well, speaking of which... The synth no longer tunes up 
> > > 
> > > correctly 
> > > 
> > >>>after 20 minutes. Now the tuning and the note intervals are 
> > > 
> > > screwed 
> > > 
> > >>>up period. So whatever needed "warming up" a few days ago 
seems 
> > > 
> > > to 
> > > 
> > >>>have failed permanently now.
> > >>>
> > >>>I just went over the soldering points around the components 
you 
> > >>>pointed out and resoldered most of them to be sure. I still 
get 
> > > 
> > > the 
> > > 
> > >>>same problem, though, so I guess it's time to start replacing 
> > >>>components. I'll definitely try testing with cooling spray. 
> Good 
> > >>>suggestion! 
> > >>>
> > >>>BTW, it seems I can replace all components in the expo 
> > > 
> > > conversion 
> > > 
> > >>>circuitry easily except Q12, Q3 and PC-1. Can't seem to find 
> > > 
> > > info on 
> > > 
> > >>>these anywhere. You wouldn't happen to know of components 
> > > 
> > > compatible 
> > > 
> > >>>to any of these three, would you?
> > >>>
> > >>>Peter
> > >>>
> > >>>
> > >>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> > >>><jo.synth@c...> wrote:
> > >>>
> > >>>
> > >>>>The hold capacitors are C56 in unit0..5. But I do not think 
> that 
> > > 
> > > it
> > > 
> > >>>>is the hold capacitors very likey. If it were, not all six 
> voices
> > >>>>would be affected equally. No, it must be something common. 
If 
> it
> > >>>>is not the wires to/from KLM-396, then the "expo converter" 
is 
> my
> > >>>>no.1 candidate. KLM-396 seems to be a part of it. The KBD 
works
> > >>>>logarithmically; that is going up a certain number of keys 
> (e.g.
> > >>>>12 for one octave) multiplies the frequency of the generated 
> note
> > >>>>by a certain factor (times 2 in case of an octave). So the 
KBD 
> CV
> > >>>>logarithmic by its nature, whereas the oscillators work 
linear;
> > >>>>that is, the generated frequency changes linearly with the 
> > > 
> > > control
> > > 
> > >>>>voltage (e.g 1V gives 1000Hz, 2V give 2000Hz, 3V give 3000Hz, 
> > >>>
> > >>>etc.).
> > >>>
> > >>>
> > >>>>These two schemes are not compatible to each other but it is 
> > >>>
> > >>>possible
> > >>>
> > >>>
> > >>>>(and necessary) to convert from one to the other. When 
> converting
> > >>>
> > >>>>from logarithmic to linear you have to do the opposite of 
> > > 
> > > logarithm
> > > 
> > >>>>which is exponential function. It happens that diodes and 
> > >>>
> > >>>transistors
> > >>>
> > >>>
> > >>>>have exponential transfer curves, so they can be used for this
> > >>>>purpose. But the exponential function is extrem sensitive to 
> > > 
> > > small
> > > 
> > >>>>variations; a small variation of the input causes a big 
change 
> at
> > >>>>the output. Furthermore the human ear is very sensitive to 
> > > 
> > > changes
> > > 
> > >>>>in pitch. This means that there must be taken special 
measures 
> > > 
> > > that
> > > 
> > >>>>the whole thing does not run out of tune.
> > >>>>The expo converter in the Polysix is made of IC17, 18, and 
19, 
> > > 
> > > Q12
> > > 
> > >>>>(the expo component), PC-1 (kind of an opto-coupling device), 
> Q3,
> > >>>>and surrounding components. In case of "old production" units
> > >>>>KLM-396 belong to this circuitry, too. Polysix has 6 voices 
but
> > >>>>the analog (de)multiplexers for the CV have 8 inputs/outputs. 
> The
> > >>>>additional 2 inputs/outputs are used for some kind of 
> calibrating
> > >>>>the exp. amplifier and thus stabilizing tuning of the 
> instrument.
> > >>>>I am not 100% sure how this works as the CPU never measures 
any
> > >>>>value and therefore cannot adjust to changing values. From 
> what I
> > >>>>can see from the code there is always the value 0 ouput 
> > > 
> > > to "voices"
> > > 
> > >>>>6 and 7.
> > >>>>
> > >>>>According to what you tell, it may be a thermal problem. So I 
> > > 
> > > would
> > > 
> > >>>>carefully check all solder points and try to heat up / cool 
> down
> > >>>>the PCB in the area where these components are located. With 
> > >>>
> > >>>cooling
> > >>>
> > >>>
> > >>>>spray you may identify a faulty component.
> > >>>>
> > >>>>Johannes
> > >>>>
> > >>>>
> > >>>>Peter Andersson wrote:
> > >>>>
> > >>>>
> > >>>>>Yes, it's an old production unit alright. I've checked the 
> > > 
> > > wires 
> > > 
> > >>>>>between the 366 and the 396. It seems ok, the solder joints 
> too.
> > >>>>>
> > >>>>>Can you tell me which major components are actually involved 
> in 
> > >>>
> > >>>the 
> > >>>
> > >>>
> > >>>>>lin/log conversion/tuning? I've been told to "check" the key 
> > >>>
> > >>>voltage 
> > >>>
> > >>>
> > >>>>>selector chip, the DAC and the S/H capacitors as well as 
> > >>>
> > >>>something 
> > >>>
> > >>>
> > >>>>>called an expo converter. (I don't understand half of this 
> > > 
> > > stuff 
> > > 
> > >>>to 
> > >>>
> > >>>
> > >>>>>be honest - I know you're not surprised. I'm learning, 
> > > 
> > > though... 
> > > 
> > >>>>>quickly!). These are some of the key components of the 366 
as 
> > >>>
> > >>>far as 
> > >>>
> > >>>
> > >>>>>I understand. Do they handle the conversion/tuning you're 
> > >>>
> > >>>refering 
> > >>>
> > >>>
> > >>>>>to? I thought I'd start out by replacing the S/H capacitors. 
> > > 
> > > The 
> > > 
> > >>>>>cheapest and easiest operation to start with, I thought. 
> > >>>
> > >>>However, I 
> > >>>
> > >>>
> > >>>>>haven't even been able to locate them. It's nearly impossibe 
> to 
> > >>>
> > >>>read 
> > >>>
> > >>>
> > >>>>>the numbers on the 366 schematics I got off the Old Crow web 
> > >>>
> > >>>site. 
> > >>>
> > >>>
> > >>>>>(Man what a fantastic resource his site is, btw!).
> > >>>>>
> > >>>>>Again, thanks for helping!
> > >>>>>
> > >>>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> > >>>>><jo.synth@c...> wrote:
> > >>>>>
> > >>>>>
> > >>>>>>From what you tell I would say it is a problem on the KLM-
> 366, 
> > >>>
> > >>>in
> > >>>
> > >>>
> > >>>>>>the log/lin conversion/tuning section.
> > >>>>>>Or maybe you have one of the rare "old production" units. 
Is 
> > >>>
> > >>>there
> > >>>
> > >>>
> > >>>>>>a small add-on board "KLM-396" to the KLM-366?
> > >>>>>>It could be a lose wire (if "old production") and/or a bad 
> > > 
> > > solder
> > > 
> > >>>>>>joint.
> > >>>>>>I can see that you are located in Sweden; maybe you ask 
> Ricard
> > >>>>>>( http://home.swipnet.se/ricard2/p6index.html ) for 
> technical 
> > >>>
> > >>>help.
> > >>>
> > >>>
> > >>>>>>Peter Andersson wrote:
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>>>Actually, tones are quite stable even during the first 20 
> > >>>>>
> > >>>>>minutes, but
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>>>the synth is not in tune generally. Also, an octave is a 
> > > 
> > > quite 
> > > 
> > >>>>>stable
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>>>major 7 interval for the first 20 minutes, until suddenly, 
> > > 
> > > the 
> > > 
> > >>>>>synth
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>>>goes into tune and then the octave is correct as well. 
I'll 
> > >>>
> > >>>check
> > >>>
> > >>>
> > >>>>>>>tonight if a single generated tone changes a lot during 
the 
> > >>>>>
> > >>>>>first 10
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>>>sec.
> > >>>>>>>
> > >>>>>>>All six voices are affected. If I play a chord when it 
> > > 
> > > suddenly 
> > > 
> > >>>>>slides
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>>>out of pitch, all notes follow. It actually sounds like 
I'm 
> > >>>>>
> > >>>>>turning
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>>>the pitch wheel. (I disconnected the pitch wheel, btw, 
just 
> > > 
> > > to 
> > > 
> > >>>>>be sure
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>>>it wasn't playing tricks on me).
> > >>>>>>>
> > >>>>>>>It is not related to the MG setting and I've played around 
> > > 
> > > with 
> > > 
> > >>>>>all
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>>>three - VCA, VCF and VCO. I'm quite sure it's not affected 
> by 
> > >>>
> > >>>the
> > >>>
> > >>>
> > >>>>>>>waveform setting either (whether I use a saw or a pulse) 
> but 
> > >>>
> > >>>I'll
> > >>>
> > >>>
> > >>>>>>>double check that tonight. The PWM setting does not make 
any
> > >>>>>>>difference.
> > >>>>>>>
> > >>>>>>>Does this give you any clues? Thanks for helping!
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner 
> > >>>>>
> > >>>>><jo.synth@c...>
> > >>>>>
> > >>>>>>>wrote:
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>>It is not normal that it takes 20 miuntes to tune up. 
> > > 
> > > Usually 
> > > 
> > >>>it
> > >>>
> > >>>
> > >>>>>>>>takes about 10sec to tune and then it is quite stable.
> > >>>>>>>>Check the following: hold a key down when switching power 
> > > 
> > > on. 
> > > 
> > >>>The
> > >>>
> > >>>
> > >>>>>>>>generated note should change quite a lot until it 
> stabilizes 
> > >>>>>
> > >>>>>after
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>>>>a few secs.
> > >>>>>>>>Are all six voice affected? Is the effect related to the 
> MG 
> > >>>>>
> > >>>>>setting
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>>>>(VCA/VCF/VCO)? Is it related to PWM setting?
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>>Peter Andersson wrote:
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>>>Hi all,
> > >>>>>>>>>
> > >>>>>>>>>I'm the proud new owner of a Polysix. I love it! Can't 
> take 
> > > 
> > > my
> > > 
> > >>>>>>>hands 
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>>>off those knobs - the filters are just great! But I'm 
> > > 
> > > having 
> > > 
> > >>>a 
> > >>>
> > >>>
> > >>>>>>>>>problem with it and I'm hoping someone can tell me what 
> it's
> > >>>>>>>
> > >>>>>>>about 
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>>>and maybe even what can be done...
> > >>>>>>>>>
> > >>>>>>>>>After I've played the synth for a while, notes start to 
> go 
> > >>>
> > >>>out 
> > >>>
> > >>>
> > >>>>>of 
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>>>>>pitch every now and then. It happens randomly every 10-
30 
> > > 
> > > sec 
> > > 
> > >>>or
> > >>>
> > >>>
> > >>>>>>>so. 
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>>>The notes go off pitch with a note or so and always jump 
> or 
> > >>>>>
> > >>>>>slide 
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>>>>>back to the original pitch again within half a second.
> > >>>>>>>>>
> > >>>>>>>>>At first I thought it was some filter setting of mine 
> that 
> > >>>>>
> > >>>>>caused 
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>>>>>it, but as it turns out I get this no matter how the 
> Poly6 
> > > 
> > > is 
> > > 
> > >>>>>>>>>programmed (or if I use a preset or a fresh "manual" 
> > > 
> > > sound). 
> > > 
> > >>>(By
> > >>>
> > >>>
> > >>>>>>>the 
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>>>way, it takes about 20 minutes for the unit to get in 
> > > 
> > > perfect
> > > 
> > >>>>>>>tune 
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>>>after a cold start. Don't know if that's normal or if 
it's
Show quoted textHide quoted text
> > >>>>>>>
> > >>>>>>>related 
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>>>to this problem in any way).
> > >>>>>>>>>
> > >>>>>>>>>I'd be truly grateful for any help!
> > >>>>>>>>>
> > >>>>>>>>>Peter
> > >>>>>>>>>
> > >>>>>>>>>
> > >>>>>>>>>
> > >>>>>>>>>
> > >>>>>>>>>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/ 
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>
> > >>>
> > >>>
> > >>>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/ 
> > > 
> > > 
> > > 
> > >
>

Re: [PolySix] Re: Notes go out of pitch

2006-08-08 by Chromatest J. Pantsmaker

That is the most common notation.  Some countries use a .  some use a , but it all makes sense when you replace both with the value.

4k7 is 4.7k or... 4,7k (europe?)

> ----- Original Message -----
> From: "sdlarch1" <sdlarch@gmail.com>
> To: PolySix@yahoogroups.com
> Subject: [PolySix] Re: Notes go out of pitch
> Date: Tue, 08 Aug 2006 02:10:13 -0000
> 
> 
> I'm not familiar with the resistor value notation used here.
> What are 4k7 and 1k2?  4.7k?  47k?
> 
> 
> --- In PolySix@yahoogroups.com, "Peter Andersson"
> <peter.peppe.andersson@...> wrote:
> >
> >
> > Hi,
> >
> > I wanted to let you know that I've finally managed to repair my 
> > Precious (Polysix). It was indeed the opto resistor, the PC-1, 
> > that was faulty. It was suggested to me that I replace the old
> mysterious
> > PC-1 component with a VTL5C3 and change R93 from 4k7 to 1k2 (to 
> > get the VTL5C3 working properly). I did and then the synth was as 
> > good as new!
> >
> > Appearently, the PC-1 is what stabilizes the expo-converter
> circuit.
> > If it's broken, the circuit can't manage to keep the synth in 
> > tune as the voltages vary (which is especially noticeable during 
> > the
> time
> > the machine is warming up).
> >
> > Thanks for the help!
> >
> >   Peter
> >
> > --- In PolySix@yahoogroups.com, Johannes Hausensteiner <jo.synth@c...> wrote:
> > > I would not start to replace all components; I would rather try
> > > to find out the faulty one. Heat up the whole area of the PCB
> > > using a hot fan. Then you can selectively cool down single
> > > components with cooling spray. If you start the Arpeggiator
> > > before you can let play the Polysix for its own and hear changes
> > > immediately.
> > > > Johannes
> > > > > Peter Andersson wrote:
> > > > You're right, searching for "2SC1583" does give me a bunch of 
> > > > interesting matches. No seller in Sweden but there are shops 
> > in > > Germany, for example, selling both that and the 2SA733. 
> > I'll
> ask
> > a > > friend to get them and post them to me. Like you say, the 
> > opto > > resistor (PC-1) could be tough to get hold of, though. 
> > I'll start by > > replacing the transistors anyway and see if 
> > that does anything. Oh, > > and what about those amplifier ICs? 
> > Is that a long shot you think? > > > > Peter
> > > > > > --- In PolySix@yahoogroups.com, Johannes Hausensteiner > 
> > > <jo.synth@c...> wrote:
> > > > > >>I read from the schematic:
> > > >>* Q12 is a dual npn transistor, common emitter.
> > > >>   The used type is 2SC1583.
> > > >>   I found a company Dönberg Electronics, who does sell this
> > > >>   component, by entering "2sc1583" into Google
> > > >>
> > > >>* Q3 is a standard (Japanese) pnp small signal transistor,
> > > >>   type 2SA733. Dönberg also do have this one or you can take
> > > >>   a BC557 as a substitute. But be careful, the pinout is
> > > >>   different:
> > > >>                  2SA733          BC557
> > > >>                   B-C-E          E-B-C
> > > >>
> > > >>* PC-1 seems to be a Korg custom component. Doesnt it have a
> > > >>   black rubber tube on it? It is drawn in the schematics as
> > > >>   an LED optically coupled to an LDR. Hm.
> > > >>   Maybe someone of the list has a spare?
> > > >>
> > > >>Johannes
> > > >>
> > > >>
> > > >>
> > > >>Peter Andersson wrote:
> > > >>
> > > >>>Wow, that's very useful info! Thanks Johannes!
> > > >>>
> > > >>>The control voltage must be crucial for the expo conversion 
> > to > > > > work > > > >>>properly then. If any of the amplifier 
> > circuits would be
> broken
> > > >>>(IC17, 18 or 19), could that cause this behaviour do you
> think,
> > > > > > or > > > >>>would that just make everything fail "from start"?
> > > >>>
> > > >>>Well, speaking of which... The synth no longer tunes up > > 
> > > > correctly > > > >>>after 20 minutes. Now the tuning and the 
> > note intervals are > > > > screwed > > > >>>up period. So 
> > whatever needed "warming up" a few days ago
> seems
> > > > > > to > > > >>>have failed permanently now.
> > > >>>
> > > >>>I just went over the soldering points around the components
> you
> > > >>>pointed out and resoldered most of them to be sure. I still
> get
> > > > > > the > > > >>>same problem, though, so I guess it's time 
> > to start replacing > >>>components. I'll definitely try testing 
> > with cooling spray. Good > >>>suggestion! > >>>
> > > >>>BTW, it seems I can replace all components in the expo > > > 
> > > conversion > > > >>>circuitry easily except Q12, Q3 and PC-1. 
> > Can't seem to find > > > > info on > > > >>>these anywhere. You 
> > wouldn't happen to know of components > > > > compatible > > > 
> > >>>to any of these three, would you?
> > > >>>
> > > >>>Peter
> > > >>>
> > > >>>
> > > >>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner > 
> > >>><jo.synth@c...> wrote:
> > > >>>
> > > >>>
> > > >>>>The hold capacitors are C56 in unit0..5. But I do not think 
> > that > > > > it
> > > > > >>>>is the hold capacitors very likey. If it were, not all six voices
> > > >>>>would be affected equally. No, it must be something common.
> If
> > it
> > > >>>>is not the wires to/from KLM-396, then the "expo converter"
> is
> > my
> > > >>>>no.1 candidate. KLM-396 seems to be a part of it. The KBD
> works
> > > >>>>logarithmically; that is going up a certain number of keys (e.g.
> > > >>>>12 for one octave) multiplies the frequency of the generated note
> > > >>>>by a certain factor (times 2 in case of an octave). So the
> KBD
> > CV
> > > >>>>logarithmic by its nature, whereas the oscillators work
> linear;
> > > >>>>that is, the generated frequency changes linearly with the 
> > > > > > control
> > > > > >>>>voltage (e.g 1V gives 1000Hz, 2V give 2000Hz, 3V give 3000Hz, > >>>
> > > >>>etc.).
> > > >>>
> > > >>>
> > > >>>>These two schemes are not compatible to each other but it is > >>>
> > > >>>possible
> > > >>>
> > > >>>
> > > >>>>(and necessary) to convert from one to the other. When converting
> > > >>>
> > > >>>>from logarithmic to linear you have to do the opposite of > 
> > > > > logarithm
> > > > > >>>>which is exponential function. It happens that diodes and > >>>
> > > >>>transistors
> > > >>>
> > > >>>
> > > >>>>have exponential transfer curves, so they can be used for this
> > > >>>>purpose. But the exponential function is extrem sensitive 
> > to > > > > small
> > > > > >>>>variations; a small variation of the input causes a big
> change
> > at
> > > >>>>the output. Furthermore the human ear is very sensitive to 
> > > > > > changes
> > > > > >>>>in pitch. This means that there must be taken special
> measures
> > > > > > that
> > > > > >>>>the whole thing does not run out of tune.
> > > >>>>The expo converter in the Polysix is made of IC17, 18, and
> 19,
> > > > > > Q12
> > > > > >>>>(the expo component), PC-1 (kind of an opto-coupling device), Q3,
> > > >>>>and surrounding components. In case of "old production" units
> > > >>>>KLM-396 belong to this circuitry, too. Polysix has 6 voices
> but
> > > >>>>the analog (de)multiplexers for the CV have 8 inputs/outputs. The
> > > >>>>additional 2 inputs/outputs are used for some kind of calibrating
> > > >>>>the exp. amplifier and thus stabilizing tuning of the instrument.
> > > >>>>I am not 100% sure how this works as the CPU never measures
> any
> > > >>>>value and therefore cannot adjust to changing values. From what I
> > > >>>>can see from the code there is always the value 0 ouput > > 
> > > > to "voices"
> > > > > >>>>6 and 7.
> > > >>>>
> > > >>>>According to what you tell, it may be a thermal problem. So 
> > I > > > > would
> > > > > >>>>carefully check all solder points and try to heat up / cool down
> > > >>>>the PCB in the area where these components are located. With > >>>
> > > >>>cooling
> > > >>>
> > > >>>
> > > >>>>spray you may identify a faulty component.
> > > >>>>
> > > >>>>Johannes
> > > >>>>
> > > >>>>
> > > >>>>Peter Andersson wrote:
> > > >>>>
> > > >>>>
> > > >>>>>Yes, it's an old production unit alright. I've checked the 
> > > > > > wires > > > >>>>>between the 366 and the 396. It seems 
> > ok, the solder joints too.
> > > >>>>>
> > > >>>>>Can you tell me which major components are actually involved in > >>>
> > > >>>the > >>>
> > > >>>
> > > >>>>>lin/log conversion/tuning? I've been told to "check" the key > >>>
> > > >>>voltage > >>>
> > > >>>
> > > >>>>>selector chip, the DAC and the S/H capacitors as well as > >>>
> > > >>>something > >>>
> > > >>>
> > > >>>>>called an expo converter. (I don't understand half of this 
> > > > > > stuff > > > >>>to > >>>
> > > >>>
> > > >>>>>be honest - I know you're not surprised. I'm learning, > > 
> > > > though... > > > >>>>>quickly!). These are some of the key 
> > components of the 366
> as
> > > >>>
> > > >>>far as > >>>
> > > >>>
> > > >>>>>I understand. Do they handle the conversion/tuning you're > >>>
> > > >>>refering > >>>
> > > >>>
> > > >>>>>to? I thought I'd start out by replacing the S/H 
> > capacitors. > > > > The > > > >>>>>cheapest and easiest operation 
> > to start with, I thought. > >>>
> > > >>>However, I > >>>
> > > >>>
> > > >>>>>haven't even been able to locate them. It's nearly impossibe to > >>>
> > > >>>read > >>>
> > > >>>
> > > >>>>>the numbers on the 366 schematics I got off the Old Crow web > >>>
> > > >>>site. > >>>
> > > >>>
> > > >>>>>(Man what a fantastic resource his site is, btw!).
> > > >>>>>
> > > >>>>>Again, thanks for helping!
> > > >>>>>
> > > >>>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner > 
> > >>>>><jo.synth@c...> wrote:
> > > >>>>>
> > > >>>>>
> > > >>>>>>From what you tell I would say it is a problem on the KLM-
> > 366, > >>>
> > > >>>in
> > > >>>
> > > >>>
> > > >>>>>>the log/lin conversion/tuning section.
> > > >>>>>>Or maybe you have one of the rare "old production" units.
> Is
> > > >>>
> > > >>>there
> > > >>>
> > > >>>
> > > >>>>>>a small add-on board "KLM-396" to the KLM-366?
> > > >>>>>>It could be a lose wire (if "old production") and/or a 
> > bad > > > > solder
> > > > > >>>>>>joint.
> > > >>>>>>I can see that you are located in Sweden; maybe you ask Ricard
> > > >>>>>>( http://home.swipnet.se/ricard2/p6index.html ) for technical > >>>
> > > >>>help.
> > > >>>
> > > >>>
> > > >>>>>>Peter Andersson wrote:
> > > >>>>>>
> > > >>>>>>
> > > >>>>>>
> > > >>>>>>
> > > >>>>>>>Actually, tones are quite stable even during the first 20 > >>>>>
> > > >>>>>minutes, but
> > > >>>>>
> > > >>>>>
> > > >>>>>
> > > >>>>>>>the synth is not in tune generally. Also, an octave is a 
> > > > > > quite > > > >>>>>stable
> > > >>>>>
> > > >>>>>
> > > >>>>>
> > > >>>>>>>major 7 interval for the first 20 minutes, until 
> > suddenly, > > > > the > > > >>>>>synth
> > > >>>>>
> > > >>>>>
> > > >>>>>
> > > >>>>>>>goes into tune and then the octave is correct as well.
> I'll
> > > >>>
> > > >>>check
> > > >>>
> > > >>>
> > > >>>>>>>tonight if a single generated tone changes a lot during
> the
> > > >>>>>
> > > >>>>>first 10
> > > >>>>>
> > > >>>>>
> > > >>>>>
> > > >>>>>>>sec.
> > > >>>>>>>
> > > >>>>>>>All six voices are affected. If I play a chord when it > 
> > > > > suddenly > > > >>>>>slides
> > > >>>>>
> > > >>>>>
> > > >>>>>
> > > >>>>>>>out of pitch, all notes follow. It actually sounds like
> I'm
> > > >>>>>
> > > >>>>>turning
> > > >>>>>
> > > >>>>>
> > > >>>>>
> > > >>>>>>>the pitch wheel. (I disconnected the pitch wheel, btw,
> just
> > > > > > to > > > >>>>>be sure
> > > >>>>>
> > > >>>>>
> > > >>>>>
> > > >>>>>>>it wasn't playing tricks on me).
> > > >>>>>>>
> > > >>>>>>>It is not related to the MG setting and I've played 
> > around > > > > with > > > >>>>>all
> > > >>>>>
> > > >>>>>
> > > >>>>>
> > > >>>>>>>three - VCA, VCF and VCO. I'm quite sure it's not affected by > >>>
> > > >>>the
> > > >>>
> > > >>>
> > > >>>>>>>waveform setting either (whether I use a saw or a pulse) but > >>>
> > > >>>I'll
> > > >>>
> > > >>>
> > > >>>>>>>double check that tonight. The PWM setting does not make
> any
> > > >>>>>>>difference.
> > > >>>>>>>
> > > >>>>>>>Does this give you any clues? Thanks for helping!
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>--- In PolySix@yahoogroups.com, Johannes Hausensteiner > >>>>>
> > > >>>>><jo.synth@c...>
> > > >>>>>
> > > >>>>>>>wrote:
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>>It is not normal that it takes 20 miuntes to tune up. > 
> > > > > Usually > > > >>>it
> > > >>>
> > > >>>
> > > >>>>>>>>takes about 10sec to tune and then it is quite stable.
> > > >>>>>>>>Check the following: hold a key down when switching 
> > power > > > > on. > > > >>>The
> > > >>>
> > > >>>
> > > >>>>>>>>generated note should change quite a lot until it 
> > stabilizes > >>>>>
> > > >>>>>after
> > > >>>>>
> > > >>>>>
> > > >>>>>
> > > >>>>>>>>a few secs.
> > > >>>>>>>>Are all six voice affected? Is the effect related to the MG > >>>>>
> > > >>>>>setting
> > > >>>>>
> > > >>>>>
> > > >>>>>
> > > >>>>>>>>(VCA/VCF/VCO)? Is it related to PWM setting?
> > > >>>>>>>>
> > > >>>>>>>>
> > > >>>>>>>>Peter Andersson wrote:
> > > >>>>>>>>
> > > >>>>>>>>
> > > >>>>>>>>
> > > >>>>>>>>
> > > >>>>>>>>
> > > >>>>>>>>>Hi all,
> > > >>>>>>>>>
> > > >>>>>>>>>I'm the proud new owner of a Polysix. I love it! Can't 
> > take > > > > my
> > > > > >>>>>>>hands > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>>>off those knobs - the filters are just great! But I'm 
> > > > > > having > > > >>>a > >>>
> > > >>>
> > > >>>>>>>>>problem with it and I'm hoping someone can tell me what it's
> > > >>>>>>>
> > > >>>>>>>about > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>>>and maybe even what can be done...
> > > >>>>>>>>>
> > > >>>>>>>>>After I've played the synth for a while, notes start to go > >>>
> > > >>>out > >>>
> > > >>>
> > > >>>>>of > >>>>>
> > > >>>>>
> > > >>>>>
> > > >>>>>>>>>pitch every now and then. It happens randomly every 10-
> 30
> > > > > > sec > > > >>>or
> > > >>>
> > > >>>
> > > >>>>>>>so. > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>>>The notes go off pitch with a note or so and always 
> > jump or > >>>>>
> > > >>>>>slide > >>>>>
> > > >>>>>
> > > >>>>>
> > > >>>>>>>>>back to the original pitch again within half a second.
> > > >>>>>>>>>
> > > >>>>>>>>>At first I thought it was some filter setting of mine that > >>>>>
> > > >>>>>caused > >>>>>
> > > >>>>>
> > > >>>>>
> > > >>>>>>>>>it, but as it turns out I get this no matter how the 
> > Poly6 > > > > is > > > >>>>>>>>>programmed (or if I use a preset 
> > or a fresh "manual" > > > > sound). > > > >>>(By
> > > >>>
> > > >>>
> > > >>>>>>>the > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>>>way, it takes about 20 minutes for the unit to get in 
> > > > > > perfect
> > > > > >>>>>>>tune > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>>>after a cold start. Don't know if that's normal or if
> it's
> > > >>>>>>>
> > > >>>>>>>related > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>>>to this problem in any way).
> > > >>>>>>>>>
> > > >>>>>>>>>I'd be truly grateful for any help!
> > > >>>>>>>>>
> > > >>>>>>>>>Peter
> > > >>>>>>>>>
> > > >>>>>>>>>
> > > >>>>>>>>>
> > > >>>>>>>>>
> > > >>>>>>>>>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/ > >>>>>
> > > >>>>>
> > > >>>>>
> > > >>>>>
> > > >>>
> > > >>>
> > > >>>
> > > >>>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
> 
> 
> 
> 

>



.sig
-Chromatest J. Pantsmaker
http://www.chromatest.net