The Kawai & Teisco Analog Synths Group

Greetings all,

I'm new to the group and a have a question for anyone who might be
able to answer it. I have the dreaded missing note problem with my
sx-240. If I play any long series of unique notes the eighth (16th,
24th, etc) is always very faint. I know it's not the keyboard b/c I
can cycle through say a nine note pattern and its always every eight
note played which means the missing note is on a different key each
time through.

What I was wondering was if there is a diagnostic mode that the synth
can be put in? I have another synth that I can cycle through each of
the voices (oscillators actually) in turn using a special mode and
it's very helpful when trying to track down these types of problems.

Cheers, and thanks for you help, Peter

P.S. Does anyone know what a service manual for one of these costs and
where I could get one?

My 240 did this when I first got it. Problem ended up being in the ribbon interconnects. They re IDC types so wires can work loose inside the connector housing

--- In kawai_sx210@yahoogroups.com, "nhanalog" <p_tengstrand@y...> 


Peter:

 I wonder if it happens on all your patches? Only 8 notes can be
played at a single moment without running out of poly. If the note is
played and released, the next note should have a chance to retrigger
reguardless of the sequence.



















wrote:

> Greetings all,
> 
> I'm new to the group and a have a question for anyone who might be
> able to answer it. I have the dreaded missing note problem with my
> sx-240. If I play any long series of unique notes the eighth (16th,
> 24th, etc) is always very faint. I know it's not the keyboard b/c I
> can cycle through say a nine note pattern and its always every eight
> note played which means the missing note is on a different key each
> time through.
> 
> What I was wondering was if there is a diagnostic mode that the synth
> can be put in? I have another synth that I can cycle through each of
> the voices (oscillators actually) in turn using a special mode and
> it's very helpful when trying to track down these types of problems.
> 
> Cheers, and thanks for you help, Peter
> 
> P.S. Does anyone know what a service manual for one of these costs and
> where I could get one?

Next step I'd determine on which oscillator the problem lays and find 
the defected chip in that circuit. I had two defective 4066 on two 
different oscillators in my SX-210, making the env sound strange ("ta 
ta ta ta") when that oscillator was engaged in a chord, but your 
particular problem seems to me more like a defective 2044 chip...

You can compare the voltages between all 2044 and the oine you 
suspect, it may show different values.



--- In kawai_sx210@yahoogroups.com, "texhand" <texhand@y...> wrote:
> --- In kawai_sx210@yahoogroups.com, "nhanalog" <p_tengstrand@y...> 
> 
> 
> Peter:
> 
>  I wonder if it happens on all your patches? Only 8 notes can be
> played at a single moment without running out of poly. If the note 
is
> played and released, the next note should have a chance to retrigger
> reguardless of the sequence.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> wrote:
> > Greetings all,
> > 
> > I'm new to the group and a have a question for anyone who might be
> > able to answer it. I have the dreaded missing note problem with my
> > sx-240. If I play any long series of unique notes the eighth 
(16th,
> > 24th, etc) is always very faint. I know it's not the keyboard b/c 
I
> > can cycle through say a nine note pattern and its always every 
eight
> > note played which means the missing note is on a different key 
each
> > time through.
> > 
> > What I was wondering was if there is a diagnostic mode that the 
synth
> > can be put in? I have another synth that I can cycle through each 
of
> > the voices (oscillators actually) in turn using a special mode and
> > it's very helpful when trying to track down these types of 
problems.
> > 
> > Cheers, and thanks for you help, Peter
> > 
> > P.S. Does anyone know what a service manual for one of these 
costs and
> > where I could get one?

--- In kawai_sx210@yahoogroups.com, "nhanalog" <p_tengstrand@y...> wrote:
> Greetings all,


Yep, I just ran through some of my patches, and some do not sound on
all keys, but the ones that do ,,, and with modulation... glad I saved
it! I have string patch that will play all notes and scales.. Sooo it
is not the sx, but my patches doing that.

> 
> I'm new to the group and a have a question for anyone who might be
> able to answer it. I have the dreaded missing note problem with my
> sx-240. If I play any long series of unique notes the eighth (16th,
> 24th, etc) is always very faint. I know it's not the keyboard b/c I
> can cycle through say a nine note pattern and its always every eight
> note played which means the missing note is on a different key each
> time through.
> 
> What I was wondering was if there is a diagnostic mode that the synth
> can be put in? I have another synth that I can cycle through each of
> the voices (oscillators actually) in turn using a special mode and
> it's very helpful when trying to track down these types of problems.
> 
> Cheers, and thanks for you help, Peter
> 
> P.S. Does anyone know what a service manual for one of these costs and
> where I could get one?

Wow. I wanted to thank everyone for all the great ideas on figuring
out this problem. It'll be a while before I can get to it but I'll be
sure to post the results of my efforts.

Cheers,
Peter

--- In kawai_sx210@yahoogroups.com, "nhanalog" <p_tengstrand@y...> wrote:

> Greetings all,
> 
> I'm new to the group and a have a question for anyone who might be
> able to answer it. I have the dreaded missing note problem with my
> sx-240. If I play any long series of unique notes the eighth (16th,
> 24th, etc) is always very faint. I know it's not the keyboard b/c I
> can cycle through say a nine note pattern and its always every eight
> note played which means the missing note is on a different key each
> time through.
> 
> What I was wondering was if there is a diagnostic mode that the synth
> can be put in? I have another synth that I can cycle through each of
> the voices (oscillators actually) in turn using a special mode and
> it's very helpful when trying to track down these types of problems.
> 
> Cheers, and thanks for you help, Peter
> 
> P.S. Does anyone know what a service manual for one of these costs and
> where I could get one?