Korg DW8000, Mono/Poly, MS-20...

Hi everyone, I know the subject looks rather silly, but I do not know
the better way to describe my problem - english is not my native language.
I just resurected DW8000 I acquired for as much as 100 euros, it was
completely dead and the battery replacement was not the clue here.
Anyway, the synth came back to life but it's just a half of success -
the issue is when I press a key the beast start sounding but it does
not stop when I release the key. Pressing another key toggles another
voice to sound and now two voices sounds forever, etc. That is how it
behaves in Poly mode, in Unison all voices sound together so pressing
another key (and relesing it) causes the previous sound stop sounding
and the one just pressed sounding forever. The strange is that the
sound is not just the sound of selected waveforms but it sounds like
the VCF in big resonance - selfoscilating at a high frequency. Another
important thing here in my opinion is that the mixed signal amplitude
leaving VCA (before it reaches the delay board) is very high and
getting higher each time I press a key. My first suspicious was a
keyboard issue but it was a false - I have tried to trigger the synth
externally via MIDI and it behaves exactly the same way.
I am looking for anyone experienced who might be knowing the way the
analog part of the DW8000 works and can share with me the knowledge. I
have skills but do not have experience and knowledge how the synth
works. I am trying to learn by just reading and analyzing schematics,
but it is very difficult and the Service Manual is ..... actually
useless. I will appreciate any piece of advice.
Thank you.


gupidziadek

Forgive me for asking what might be a stupid question, but did you reload the programs?  Since you replaced the battery, the program memory was wiped out-- it sounds like maybe the Release parameter is set to maximum on all the patches.
Reloading the factory patches (or any you might have on hand that are known to be good) should tell you if it's a memory problem or a synth problem.

~GMM

At 09:00 AM 1/2/2007, you wrote:

Hi everyone, I know the subject looks rather silly, but I do not know
the better way to describe my problem - english is not my native language.
I just resurected DW8000 I acquired for as much as 100 euros, it was
completely dead and the battery replacement was not the clue here.
Anyway, the synth came back to life but it's just a half of success -
the issue is when I press a key the beast start sounding but it does
not stop when I release the key. Pressing another key toggles another
voice to sound and now two voices sounds forever, etc. That is how it
behaves in Poly mode, in Unison all voices sound together so pressing
another key (and relesing it) causes the previous sound stop sounding
and the one just pressed sounding forever. The strange is that the
sound is not just the sound of selected waveforms but it sounds like
the VCF in big resonance - selfoscilating at a high frequency. Another
important thing here in my opinion is that the mixed signal amplitude
leaving VCA (before it reaches the delay board) is very high and
getting higher each time I press a key. My first suspicious was a
keyboard issue but it was a false - I have tried to trigger the synth
externally via MIDI and it behaves exactly the same way.
I am looking for anyone experienced who might be knowing the way the
analog part of the DW8000 works and can share with me the knowledge. I
have skills but do not have experience and knowledge how the synth
works. I am trying to learn by just reading and analyzing schematics,
but it is very difficult and the Service Manual is ..... actually
useless. I will appreciate any piece of advice.
Thank you.

gupidziadek

Have you tried disconnecting the keyboard and playing it through MIDI?

No, I did not try to disconnect the keyboard, although I tried to play
the synth through MIDI. I do not think it is a problem with local
keyboard, because pressing/releasing keys sends MIDI messages just
fine - I checked that with MIDIOX. What I tried was disconnecting the
Aftertouch "mechanism" but it changed a thing. Anyway, I am going to
try to disconnect the local keyboard and then try to play through
MIDI, as you suggest.

Thanks

--- In DW8000@yahoogroups.com, Jez <jezosaurus@...> wrote:
>
> Have you tried disconnecting the keyboard and playing it through MIDI?
>
> On 1/2/07, gupidziadek <dmaliszewski@...> wrote:
> >
> > Hi everyone, I know the subject looks rather silly, but I do not
know
> > the better way to describe my problem - english is not my native
language.
> > I just resurected DW8000 I acquired for as much as 100 euros, it was
> > completely dead and the battery replacement was not the clue here.
> > Anyway, the synth came back to life but it's just a half of success -
> > the issue is when I press a key the beast start sounding but it does
> > not stop when I release the key. Pressing another key toggles another
> > voice to sound and now two voices sounds forever, etc. That is how it
> > behaves in Poly mode, in Unison all voices sound together so pressing
> > another key (and relesing it) causes the previous sound stop sounding
> > and the one just pressed sounding forever. The strange is that the
> > sound is not just the sound of selected waveforms but it sounds like
> > the VCF in big resonance - selfoscilating at a high frequency. Another
> > important thing here in my opinion is that the mixed signal amplitude
> > leaving VCA (before it reaches the delay board) is very high and
> > getting higher each time I press a key. My first suspicious was a
> > keyboard issue but it was a false - I have tried to trigger the synth
> > externally via MIDI and it behaves exactly the same way.
> > I am looking for anyone experienced who might be knowing the way the
> > analog part of the DW8000 works and can share with me the knowledge. I
> > have skills but do not have experience and knowledge how the synth
> > works. I am trying to learn by just reading and analyzing schematics,
> > but it is very difficult and the Service Manual is ..... actually
> > useless. I will appreciate any piece of advice.
> > Thank you.
> >
> > gupidziadek
> >
> >
> >
>

No, that's not a stupid question, I was thinking of the programs I
reloaded to be the cause of my problems, but I reloaded them several
times. And it was not just one set of programs but a few - I took them
from Bryan Ressler's web page. The effect is still the same. I also
cleared memory several times (buttons 5,8 during restart). But I think
the value for Release parameter you wrote about might be the point
here - that's my suspicious as well - and I also think of VCF
Resonance as of another cause of the issue. The problem is that both
things are being realized by NJM2069, as far as I know and if that is
true and the one is damaged, then I am simply defeated. But on the
other hand there is rather small possibillity that each and everyone
of the 8 NJM2069 on the board is damaged, is not it? Yet each voice is
affected by the issue.
Anyway, thanks for the advice.

gupidziadek

--- In DW8000@yahoogroups.com, klosmon <klosmon@...> wrote:
>
> Forgive me for asking what might be a stupid question, but did you
reload
> the programs? Since you replaced the battery, the program memory
was wiped
> out-- it sounds like maybe the Release parameter is set to maximum
on all
> the patches.
> Reloading the factory patches (or any you might have on hand that
are known
> to be good) should tell you if it's a memory problem or a synth problem.
>
> ~GMM
>
> At 09:00 AM 1/2/2007, you wrote:
>
> >Hi everyone, I know the subject looks rather silly, but I do not know
> >the better way to describe my problem - english is not my native
language.
> >I just resurected DW8000 I acquired for as much as 100 euros, it was
> >completely dead and the battery replacement was not the clue here.
> >Anyway, the synth came back to life but it's just a half of success -
> >the issue is when I press a key the beast start sounding but it does
> >not stop when I release the key. Pressing another key toggles another
> >voice to sound and now two voices sounds forever, etc. That is how it
> >behaves in Poly mode, in Unison all voices sound together so pressing
> >another key (and relesing it) causes the previous sound stop sounding
> >and the one just pressed sounding forever. The strange is that the
> >sound is not just the sound of selected waveforms but it sounds like
> >the VCF in big resonance - selfoscilating at a high frequency. Another
> >important thing here in my opinion is that the mixed signal amplitude
> >leaving VCA (before it reaches the delay board) is very high and
> >getting higher each time I press a key. My first suspicious was a
> >keyboard issue but it was a false - I have tried to trigger the synth
> >externally via MIDI and it behaves exactly the same way.
> >I am looking for anyone experienced who might be knowing the way the
> >analog part of the DW8000 works and can share with me the knowledge. I
> >have skills but do not have experience and knowledge how the synth
> >works. I am trying to learn by just reading and analyzing schematics,
> >but it is very difficult and the Service Manual is ..... actually
> >useless. I will appreciate any piece of advice.
> >Thank you.
> >
> >gupidziadek
> >
> >
>

Jez wrote:

> Have you tried disconnecting the keyboard and playing it through MIDI?

> On 1/2/07, gupidziadek <dmaliszewski@...> wrote:
>> <SNIP>
>> My first suspicious was a
>> keyboard issue but it was a false - I have tried to trigger the synth
>> externally via MIDI and it behaves exactly the same way.

He tried that.

I had a similar problem.  Try switching to a patch where you can audibly hear the second oscillator.  Adjust the second oscillator's level in the parameter section.  Can you hear the drone sound being affected by adjusting the second oscillator's volume?