Discussion about the Korg PolySix synthesizer

Hi,

After bringing my dead Polysix back to life (Battery leakage,
faulty SSM 2056's) I decided to give him a completely new
calibration.

There are 2 points in the service manual which I have
difficulties to understand:


- In "KLM-366 check and adjustment", point (3) "VCF RESONANCE
adjustment":

"Check CN05-7 with DVM and adjust to obtain 8.000V +/- 20mV"

What am I supposed to adjust ?

- In "KLM-367 adjustment", point (4) "PW/PWM check and adjustment":

"...confirm there is a DC component of +0.2 ~ +0.5V"

My Polysix shows an offset of about 1.6V ... any ideas ?


Thanks in advance for any hints...


Regards,

Andreas.

Hi,

1) Adjust the RESONANCE knob for a 8.000V reading on the DVM.
When trying to accomplish this you will notice that there
are discrete steps in the value. Because our beloved analog
baby is controlled *digitally* in reality. The analog
control voltages (+/-5V) are digitized with 8 bits
(256 steps), which gives a resolution of about 40mV.

2) This is misleading in the service manual. They do not mean
the DC component but rather the the *minimum* value of the
triangle waveform is supposed to be 0.2 ~ 0.5V. When you
look at Fig. 4 this will be clear. The average value you
will measure with a DVM will add half of the triangle wave
amplitude, which results in 1.1 ~ 1.6V. So you are still
within spec.


Cheers,

Johannes


PolySix@yahoogroups.com,Internet writes:

>
>Hi,
>
>After bringing my dead Polysix back to life (Battery leakage,
>faulty SSM 2056's) I decided to give him a completely new
>calibration.
>
>There are 2 points in the service manual which I have
>difficulties to understand:
>
>
>- In "KLM-366 check and adjustment", point (3) "VCF RESONANCE
> adjustment":
>
> "Check CN05-7 with DVM and adjust to obtain 8.000V +/- 20mV"
>
>What am I supposed to adjust ?
>
>- In "KLM-367 adjustment", point (4) "PW/PWM check and adjustment":
>
> "...confirm there is a DC component of +0.2 ~ +0.5V"
>
>My Polysix shows an offset of about 1.6V ... any ideas ?
>
>
>Thanks in advance for any hints...
>
>
>Regards,
>
> Andreas.
>
>
>To unsubscribe from this group, send an email to:
>PolySix-unsubscribe@egroups.com
>
>PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>

Johannes,

Thanks for your detailed explantion. I initialy adjusted the
RESONANCE knob for 8V, unfortunately my max. resonance
frequency is about 16KHz in step "VCF fo adjustment", not
19 ~ 24KHz.

The "minimum value of the waveform" is 1.6V (On the scope,
not DVM), maybe I have to check the D/A offset on the input
of the DeMux ...


Cheers,

Andreas.


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

> Hi,
>
> 1) Adjust the RESONANCE knob for a 8.000V reading on the DVM.
> When trying to accomplish this you will notice that there
> are discrete steps in the value. Because our beloved analog
> baby is controlled *digitally* in reality. The analog
> control voltages (+/-5V) are digitized with 8 bits
> (256 steps), which gives a resolution of about 40mV.
>
> 2) This is misleading in the service manual. They do not mean
> the DC component but rather the the *minimum* value of the
> triangle waveform is supposed to be 0.2 ~ 0.5V. When you
> look at Fig. 4 this will be clear. The average value you
> will measure with a DVM will add half of the triangle wave
> amplitude, which results in 1.1 ~ 1.6V. So you are still
> within spec.
>
>
> Cheers,
>
> Johannes
>
>
> PolySix@yahoogroups.com,Internet writes:
> >
> >Hi,
> >
> >After bringing my dead Polysix back to life (Battery leakage,
> >faulty SSM 2056's) I decided to give him a completely new
> >calibration.
> >
> >There are 2 points in the service manual which I have
> >difficulties to understand:
> >
> >
> >- In "KLM-366 check and adjustment", point (3) "VCF RESONANCE
> > adjustment":
> >
> > "Check CN05-7 with DVM and adjust to obtain 8.000V +/- 20mV"
> >
> >What am I supposed to adjust ?
> >
> >- In "KLM-367 adjustment", point (4) "PW/PWM check and adjustment":
> >
> > "...confirm there is a DC component of +0.2 ~ +0.5V"
> >
> >My Polysix shows an offset of about 1.6V ... any ideas ?
> >
> >
> >Thanks in advance for any hints...
> >
> >
> >Regards,
> >
> > Andreas.
> >
> >
> >To unsubscribe from this group, send an email to:
> >PolySix-unsubscribe@egroups.com
> >
> >PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> >
> >Your use of Yahoo! Groups is subject to

http://docs.yahoo.com/info/terms/

> >
> >
> >

Sorry, I had a typo in my original question, I am still wondering
what to adjust to get 0V at CN05-7 (_not_ the 8V on CN05-11)

If I adjust VCF CUTOFF to 0V, my max res freq is about 16KHz,
(as mentioned below) VCF RESONANCE has no effect on CN05-7.


Thanks again,

Andreas.

--- In PolySix@yahoogroups.com, "winzigus <at@t...>" <at@t...> wrote:
>
> Johannes,
>
> Thanks for your detailed explantion. I initialy adjusted the
> RESONANCE knob for 8V, unfortunately my max. resonance
> frequency is about 16KHz in step "VCF fo adjustment", not
> 19 ~ 24KHz.
>
> The "minimum value of the waveform" is 1.6V (On the scope,
> not DVM), maybe I have to check the D/A offset on the input
> of the DeMux ...
>
>
> Cheers,
>
> Andreas.
>
>
> --- In PolySix@yahoogroups.com, "J. Hausensteiner" <jo.synth@c...>
> wrote:
> > Hi,
> >
> > 1) Adjust the RESONANCE knob for a 8.000V reading on the DVM.
> > When trying to accomplish this you will notice that there
> > are discrete steps in the value. Because our beloved analog
> > baby is controlled *digitally* in reality. The analog
> > control voltages (+/-5V) are digitized with 8 bits
> > (256 steps), which gives a resolution of about 40mV.
> >
> > 2) This is misleading in the service manual. They do not mean
> > the DC component but rather the the *minimum* value of the
> > triangle waveform is supposed to be 0.2 ~ 0.5V. When you
> > look at Fig. 4 this will be clear. The average value you
> > will measure with a DVM will add half of the triangle wave
> > amplitude, which results in 1.1 ~ 1.6V. So you are still
> > within spec.
> >
> >
> > Cheers,
> >
> > Johannes
> >
> >
> > PolySix@yahoogroups.com,Internet writes:
> > >
> > >Hi,
> > >
> > >After bringing my dead Polysix back to life (Battery leakage,
> > >faulty SSM 2056's) I decided to give him a completely new
> > >calibration.
> > >
> > >There are 2 points in the service manual which I have
> > >difficulties to understand:
> > >
> > >
> > >- In "KLM-366 check and adjustment", point (3) "VCF RESONANCE
> > > adjustment":
> > >
> > > "Check CN05-7 with DVM and adjust to obtain 8.000V +/- 20mV"
> > >
> > >What am I supposed to adjust ?
> > >
> > >- In "KLM-367 adjustment", point (4) "PW/PWM check and
adjustment":
> > >
> > > "...confirm there is a DC component of +0.2 ~ +0.5V"
> > >
> > >My Polysix shows an offset of about 1.6V ... any ideas ?
> > >
> > >
> > >Thanks in advance for any hints...
> > >
> > >
> > >Regards,
> > >
> > > Andreas.
> > >
> > >
> > >To unsubscribe from this group, send an email to:
> > >PolySix-unsubscribe@egroups.com
> > >
> > >PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> > >
> > >Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
> > >