Discussion about the Korg PolySix synthesizer

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.
> >
> >
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> >
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> >
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> >
> >
> >