The Kawai & Teisco Analog Synths Group

Hello group.

First, this is a great knowledge base. I read nearly all of the post.
But it seems that my problem is slightly different.

When I play some sound, one oscillator stucks with the note until it 
is retriggered by another.
i.e. I play c-d-e-f-g the g stucks - keeps on sounding regardless 
what the ENV looks like - then I play futher on a-b-c-d-e and the e 
stucks again,releasing the prior stuck g.
Do you know what I mean?

I did not open the SX210 so far to check the battery.
Any healing far-distance diagnostics?

Cheers, mike

If the stuck note happens every 8 notes played, than it is a specific 
voice (oscillator) related problem, probably a bad IC in the envelope 
section.

You need to determine which voice is the one which the problem lays 
in. Most of the times, when you power the unit up and start playing, 
the first note played will get directed to the first voice, the 
second note to the second voice etc. 

I already had 2 bad 4066 chips in mine, so I bet on a bad 4066 in 
yours as well. You will need to get (or purchase) a schematic manual, 
or just go over with an audio scope and try to find the bad IC.




--- In kawai-teisco@yahoogroups.com, "mike.rophun" <mike.rophun@...> 
wrote:
>
> Hello group.
> 
> First, this is a great knowledge base. I read nearly all of the 
post.
> But it seems that my problem is slightly different.
> 
> When I play some sound, one oscillator stucks with the note until 
it 

> is retriggered by another.
> i.e. I play c-d-e-f-g the g stucks - keeps on sounding regardless 
> what the ENV looks like - then I play futher on a-b-c-d-e and the e 
> stucks again,releasing the prior stuck g.
> Do you know what I mean?
> 
> I did not open the SX210 so far to check the battery.
> Any healing far-distance diagnostics?
> 
> Cheers, mike
>

Thanks for the quick answer.
I thought of something like a "bad voice".
So, how do I open the SX210?
I found many screws at the bottom and also some on top or at the back.
Do I have to unscrew all of them or only the big ones?
I do not want to loosen things inside...

Cheers, Mike

--- In kawai-teisco@yahoogroups.com, "gil_we" <gil_we@...> wrote:
>
> If the stuck note happens every 8 notes played, than it is a 
specific 
> voice (oscillator) related problem, probably a bad IC in the 
envelope 
> section.
> 
> You need to determine which voice is the one which the problem lays 
> in. Most of the times, when you power the unit up and start 
playing, 
> the first note played will get directed to the first voice, the 
> second note to the second voice etc. 
> 
> I already had 2 bad 4066 chips in mine, so I bet on a bad 4066 in 
> yours as well. You will need to get (or purchase) a schematic 
manual, 
> or just go over with an audio scope and try to find the bad IC.
> 
> 
> 
> 
> --- In kawai-teisco@yahoogroups.com, "mike.rophun" <mike.rophun@> 
> wrote:
> >
> > Hello group.
> > 
> > First, this is a great knowledge base. I read nearly all of the 
> post.
> > But it seems that my problem is slightly different.
> > 
> > When I play some sound, one oscillator stucks with the note until 
> it 
> > is retriggered by another.
> > i.e. I play c-d-e-f-g the g stucks - keeps on sounding regardless 
> > what the ENV looks like - then I play futher on a-b-c-d-e and the 
e 

> > stucks again,releasing the prior stuck g.
> > Do you know what I mean?
> > 
> > I did not open the SX210 so far to check the battery.
> > Any healing far-distance diagnostics?
> > 
> > Cheers, mike
> >
>

only the top and bottom big ones....




--- In kawai-teisco@...m, "mike.rophun" <mike.rophun@...>
wrote:

>
> Thanks for the quick answer.
> I thought of something like a "bad voice".
> So, how do I open the SX210?
> I found many screws at the bottom and also some on top or at the back.
> Do I have to unscrew all of them or only the big ones?
> I do not want to loosen things inside...
> 
> Cheers, Mike
> 
> --- In kawai-teisco@yahoogroups.com, "gil_we" <gil_we@> wrote:
> >
> > If the stuck note happens every 8 notes played, than it is a 
> specific 
> > voice (oscillator) related problem, probably a bad IC in the 
> envelope 
> > section.
> > 
> > You need to determine which voice is the one which the problem lays 
> > in. Most of the times, when you power the unit up and start 
> playing, 
> > the first note played will get directed to the first voice, the 
> > second note to the second voice etc. 
> > 
> > I already had 2 bad 4066 chips in mine, so I bet on a bad 4066 in 
> > yours as well. You will need to get (or purchase) a schematic 
> manual, 
> > or just go over with an audio scope and try to find the bad IC.
> > 
> > 
> > 
> > 
> > --- In kawai-teisco@yahoogroups.com, "mike.rophun" <mike.rophun@> 
> > wrote:
> > >
> > > Hello group.
> > > 
> > > First, this is a great knowledge base. I read nearly all of the 
> > post.
> > > But it seems that my problem is slightly different.
> > > 
> > > When I play some sound, one oscillator stucks with the note until 
> > it 
> > > is retriggered by another.
> > > i.e. I play c-d-e-f-g the g stucks - keeps on sounding regardless 
> > > what the ENV looks like - then I play futher on a-b-c-d-e and the 
> e 
> > > stucks again,releasing the prior stuck g.
> > > Do you know what I mean?
> > > 
> > > I did not open the SX210 so far to check the battery.
> > > Any healing far-distance diagnostics?
> > > 
> > > Cheers, mike
> > >
> >
>

The schematic for the 210 is here in the files section. You ll need it to  have it repaired. ... From: gil_we To: kawai-teisco@yahoogroups.com Subject: