Discussion about the Korg PolySix synthesizer

Enjoy your book. It'll probably give you an overview of microprocessor
system, however, the op code mnemonics are different on the 80xx series of
processor used in the P6. Have a look for the 8048/49 datasheets for more
details to clarify the differences!

 

Cheers,

Andy

 

From: PolySix@yahoogroups.com [mailto:PolySix@yahoogroups.com] On Behalf Of
Mike Borish
Sent: 07 August 2009 04:45
To: PolySix@yahoogroups.com
Subject: Re: [PolySix] Re: Problems with parasitic LFO in VCA?

 

  

Thanks for all of your help.  Does anybody have any suggestions for solving
this ring mod problem that I have?  I just downloaded a book on the Z80
processor.  It's going to take me a long time to finish the book and figure
out how this thing works.

-Mike

--- On Wed, 8/5/09, klosmon <klosmon@sbcglobal.net
<mailto:klosmon%40sbcglobal.net> > wrote:

From: klosmon <klosmon@sbcglobal.net <mailto:klosmon%40sbcglobal.net> >
Subject: Re: [PolySix] Re: Problems with parasitic LFO in VCA?
To: PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com> 
Date: Wednesday, August 5, 2009, 9:59 AM

mborish_2000 wrote:
>  
>
> That solved it.
>

OK. To restore the mod circuit without the noise:
On the bottom of the CPU board, cut the trace from pin 2 of CN06;
solder a wire from pin 2 to the free end of R9 (the resistor previously 
desoldered).
The correct end is the one closest to CN05.
This should restore all VCO mod functions, without the bleed through.

> Thank you so much Klosmon. Unsuprisingly, I discovered another problem 
> after the first one. My Effects section is always engaged and is 
> producing some strange ring modulation type sounds depending on the 
> value of the speed/intensity knob. Is this related to the first problem?
>

As Andrew stated in another post, this is probably due to an incomplete 
battery leak repair job.
Could be a latch,  data line, etc.

~GMM

>
>
> -Mike
>
> --- In PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com>
<mailto:PolySix%40yahoogroups.com>, 
> klosmon <klosmon@...> wrote:
> >
> > One frequent problem with the CPU board can cause unwanted 
> modulation of
> > the VCO, which can sound like what you're describing.
> > To see if this is the case, get a soldering iron & lift one end of R9,
> > which is a 10K resistor located between IC8 and CN05.
> > This will disconnect all modulation to the VCO; if it eliminates the
> > problem, let me know, and I'll describe where to go f rom there.
> >
> > ~GMM
> >
> > mborish_2000 wrote:
> > >
> > >
> > > I've got a few problems that I can't figure out. Unfortunately, my 
> LFO
> > > is bleeding into the VCA? and I can't figure out a way to stop it.
> > > It's not a violent bleed but it's enought to make the Polysix
> > > unusable. If I turn all of the controls down, it is still there. All
> > > of the controls are functional. All of the potentiometers test out 
> OK.
> > > I tested all cables for continuity. I cleaned the LFO modulation
> > > select switch and replaced the 4051 on KLM 369 without any luck. I
> > > read somewhere that somebody suggested cutting a trace, but they
> > > couldn't remember enough details about what they did. I didn't see 
> any
> > > calibration proceedure related to the LFO modulation either.
> > > Everything else works fine.
> > >
> > > Does anybody have any suggestions? Logic and microprocessing are
> > > really beyond my knowledge.
> > >
> > > -Mike
> > >
> >
> >
> > >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
> 

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