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.comSubject: 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]
> >
>
>
[Non-text portions of this message have been removed]
------------------------------------
PolySix "Digiest" Page:
http://www.acc.umu.se/~amber/Poly6Yahoo! Groups
Links
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]