Terje Winther

#746

Hi all,
I just subscribed to this groups, and thought I might introduce myself.
I have loved synthesizers for as long as I can remember (all the way  back into the 1970s...). I make music with synths, repair them, and  even build some. The Xpander and Matrix-12 are facinating instruments,  and I have just gotten a Matrix-12 in for service, so finally I can  take the time to learn more about these instruments. It has all the  usual errors; one key broken, one rotary encoder mailfunctoning, auto- tune turns out the usual errors, but apart form that is seems to be  mostly in order.
More about me, my music, gear and all that at:   


Terje Winther
terje.winther@...

envia94

#747

Hello Terje, let me just welcome you!

There are a lot of interesting listening in your web page (). Thanks!

I hope you'll also find some interesting things about Xpander/M12 in our Files and Photos sections especially:

Tiitu

#750

Hi Terje,

Welcome to the group.? Watch out, you might get hooked, and have to acquire one?for yourself.

?

You will find posts here on all the fails you mention.

Encoder? - Clean or replace Schmidt trigger chip connected to the failed encoder

Tune Fail - Coupling Caps Usually Cx49? x = channel #

?

I have fixed quite a few of these. I am happy to offer?any help.

Have Fun!

?

Kindest Regards

?

Karl Schmeer

?

Show quoted text

--- On Thu, 2/11/10, Terje Winther wrote:

From: Terje Winther <terje.winther@...>
Subject: [xpantastic] Xpanding my horizon
To: xpantastic@...
Date: Thursday, February 11, 2010, 7:19 AM

?

Hi all,
I just subscribed to this groups, and thought I might introduce myself.
I have loved synthesizers for as long as I can remember (all the way
back into the 1970s...). I make music with synths, repair them, and
even build some. The Xpander and Matrix-12 are facinating instruments,
and I have just gotten a Matrix-12 in for service, so finally I can
take the time to learn more about these instruments. It has all the
usual errors; one key broken, one rotary encoder mailfunctoning, auto-
tune turns out the usual errors, but apart form that is seems to be
mostly in order.
More about me, my music, gear and all that at:

Terje Winther

Terje Winther

#751

Hi all,

Thanks a lot for the warm welcome.

Welcome to the group.? Watch out, you might get hooked, and have to acquire one?for yourself.

Yes, I am afraid that is going to happen.

We?ll see. I start working on it the coming Monday, as soon as I have read through all the excellent tips on this group.

Terje Winther

terje.winther@...

#753

Terje Winther wrote:
Hi all,
I just subscribed to this groups, and thought I might introduce myself.
I have loved synthesizers for as long as I can remember (all the way  back into the 1970s...). I make music with synths, repair them, and  even build some. The Xpander and Matrix-12 are facinating instruments,  and I have just gotten a Matrix-12 in for service, so finally I can  take the time to learn more about these instruments. It has all the  usual errors; one key broken, one rotary encoder mailfunctoning, auto- tune turns out the usual errors, but apart form that is seems to be  mostly in order.
More about me, my music, gear and all that at:   Hi Terje,

Welcome to the group.  Listmates, I play Terje's music on my radio shows.  I recommend that you take a listen to his music.

Cheers,

Bill

Terje Winther

#761

Hi all,
I am well into the service of the Matrix-12. Surprisingly, there are a
lot of things that works, even though it all seems a bit worn.
I am slowly learning to program this giant, so that I don?t do any
errors out of mistakes.
There are a few hardware parts that need to be changed (a key is
broken, the levels are scratchy, number "3" on the numeric keypad is not responsive etc.), but today I came across a peculiar problem: it
seems that this unit is in 5-voice mode. Voice 6 seems to be dead, and
the unit is just jumping over that voice when cycling voices, so there
are never any "dead" voices. Is this some clever trick of the logic,
or has the synth itself detected that one voice is dead?
It does sound fat, though  :-)

Terje Winther
terje.winther@...

#762

Hi Terje,

?

Sounds like he has one voice turned off.

?

Push these buttons to access this:

Master Page> Page 2 >? Voices On/Off

?

Each voice can be turned on or off here. Odds are good, that the voice turned off, is malfunctioning,??

Good Luck

?

Karl Schmeer

Show quoted text

--- On Tue, 2/23/10, Terje Winther wrote:

From: Terje Winther
Subject: Re: [xpantastic] Xpanding my horizon
To: xpantastic@...
Date: Tuesday, February 23, 2010, 2:01 PM

?

Hi all,
I am well into the service of the Matrix-12. Surprisingly, there are a
lot of things that works, even though it all seems a bit worn.
I am slowly learning to program this giant, so that I don?t do any
errors out of mistakes.
There are a few hardware parts that need to be changed (a key is
broken, the levels are scratchy, number "3" on the numeric keypad is
not responsive etc.), but today I came across a peculiar problem: it
seems that this unit is in 5-voice mode. Voice 6 seems to be dead, and
the unit is just jumping over that voice when cycling voices, so there
are never any "dead" voices. Is this some clever trick of the logic,
or has the synth itself detected that one voice is dead?
It does sound fat, though :-)

Terje Winther

Terje Winther

#764

Hi all, and thanks for all the input regarding the Matrix-12 repair
that I am doing.
The unit is in very good shape and sounds good. Among other things all
the displays are fine, panel is good, wooden sides are in fine shape,
and all keys (except one broken) looks good.
There are some trouble manuvering the synth, as several buttons don?t
respond. It was kind of dirty before I started working on it, so I
guess several of the buttons needs to be cleaned, as I had to do with
they keys (both keytops and key contacts).

I have run across some various interesting failures:
- One voice is dead, and I have pinpointed this to the fact that the
VCA output (leg no. 14) of the CEM3372 is dead. All else on the chips
works as it should; inputs, VCF sections and all. It is just the VCA
that is gone. Usually when a CEM chip fails it is completely dead, so
this was a puzzle for me. Swapping chips with other voices turns it
into a working voice. So a new chip is needed here, then.
- The rotary encoders all work, thankfully. It is just the Schmidt
trigger chips that seems to mailfunction, just as Karl Schmeer
suggested (thanks!). If I rotate the encoder with a very specific
speed - slowly, but not too slowly - I can make it increase somewhat, but it is difficult. Reducing with the same encoder is no problem.
Need new chips probably, or maybe just clean up?

Then the real problems:
- Only voices 1-6 can be heard. Internally all voices (both 1-6 and
7-12) seems to work fine (I can scope it all). This might be connected
to the next problem...
- The "Voices 1-6 / Voices 7-12" button is unresponsive, so I have no
way to see if the second voice board is turned off or not. Are there
any workaround for this?
- Unresponsive buttons. How do you usually solve this? Clean them, or
change them? It seems to me that there are standard momentary buttons
underneath the large black front panel buttons.

The power supply have a fairly high physical hum, so at one point it
probably needs to be changed. The internal power is stable, but a
little bit off spec, like +12.1 and -11.82. Is this to much off? I
hope not, because that means I have to rebuild the whole power, with
new regulator transistors and all.

Terje Winther
terje.winther@...

#765

Hi Terje,

--- On Sun, 2/28/10, Terje Winther <terje.winther@...> wrote:
From: Terje Winther <terje.winther@...>
Subject: Re: [xpantastic] Xpanding my horizon
To: xpantastic@...
Date: Sunday, February 28, 2010, 9:16 AM
Hi all, and thanks for all the input regarding the Matrix-12 repair
that I am doing.
The unit is in very good shape and sounds good. Among other things all
the displays are fine, panel is good, wooden sides are in fine shape,
and all keys (except one broken) looks good.
There are some trouble manuvering the synth, as several buttons don?t
respond. It was kind of dirty before I started working on it, so I
guess several of the buttons needs to be cleaned, as I had to do with
they keys (both keytops and key contacts).Good idea, you also might swing out the displays ( board is hinged ) and clean the
glass of the VFD's as well as the front panel bezel.  It can really spiff it up.

I have run across some various interesting failures:
- One voice is dead, and I have pinpointed this to the fact that the
VCA output (leg no. 14) of the CEM3372 is dead. All else on the chips
works as it should; inputs, VCF sections and all. It is just the VCA
that is gone. Usually when a CEM chip fails it is completely dead, so
this was a puzzle for me. Swapping chips with other voices turns it
into a working voice. So a new chip is needed here, then.You can still find those.

- The rotary encoders all work, thankfully. It is just the Schmidt
trigger chips that seems to mailfunction, just as Karl Schmeer
suggested (thanks!). If I rotate the encoder with a very specific
speed - slowly, but not too slowly - I can make it increase somewhat,
but it is difficult. Reducing with the same encoder is no problem.
Need new chips probably, or maybe just clean up?Thanx
That is exactly the symptom I had.  I thought the encoaders were dirty but a little checking with a scope
revealed a distoted output of the trigger chip.
I used 74HC14 chip. You can get them for cheap.
I Changed out U6 and U13 on the potentiometer board. Its faster than taking the
encoaders apart and cleaning them but you may have to do this anyway.

Then the real problems:
- Only voices 1-6 can be heard. Internally all voices (both 1-6 and
7-12) seems to work fine (I can scope it all). This might be connectedQuestion: when you say unresponsive, I imagine you mean the voices can not be heard,
but what about the little green dots on the display?  There are dots that show which
voices are being played on the Programmer display.  Do these not light up?

to the next problem...
- The "Voices 1-6 / Voices 7-12" button is unresponsive, so I have no
way to see if the second voice board is turned off or not. Are there
any workaround for this?You may know this already but, That button is only active in multi mode.

The buttons are just momentary push buttons.  You could solder another pushbutton ( Normally open)
in it's place, on the bottom of the board with long extension wires.
This would be a temporary fix,  just so you can access voices 7 - 12.

I can think of a some reasons the upper voices (7 - 12)  would not play:

I am going on the  assumption that all voices are set to the same patch.
A patch could have a VCA mod by a footswitch residing in voices 7 - 12, causing them to be mute.

1) Voices 7 - 12 turned off in master page.
2) Voices 7 - 12 Pan setting to off. ( in the master page)

- Unresponsive buttons. How do you usually solve this? Clean them, or
change them? It seems to me that there are standard momentary buttons
underneath the large black front panel buttons.I have had some luck with cleaning them but replacement is better. They used to be readily available,
but not so much anymore. I need to replace some of mine, to tell you the truth but
still need to find a modern part number.
Anyone?

The power supply have a fairly high physical hum, so at one point it
probably needs to be changed. The internal power is stable, but a
little bit off spec, like +12.1 and -11.82. Is this to much off? I
hope not, because that means I have to rebuild the whole power, with
new regulator transistors and all.I have seen the transformer cause hum like this. It is not failed, the metal plates of the transformer have come loose
and vibrate with the line frequency. There is no fix short of replacing the transformer.

The voltages sound close enough to be OK. If you scope it and there is no appreciable ripple < 50 mv
the power supply is probobly OK.
BTW  It might not be a  bad idea to the power supply. The electrolytic caps in the power supply get the most abuse, And are the most likly thing to fail "in anything electronic".


Best Luck

Karl Schmeer

Terje Winther

#779

Hi all, and thanks for all the help regarding fixing the M12.
I am slowly progressing:
- Now all voices, both 1-6 and 7-12 works (apart from one voice), but
it still doesn?t tune properly. Massive sounds from 11 VCOs though  :-)
- I found a strange repeating ripple of approx. 100 - 150 mV from the
power supply. It looks (on the scope) like two ripples rather close,  then an interval, and then the two ripples repeat again, all
microseconds apart. I?ve read in the archives that this could be
enough to throw off the auto-tune process, so I better recap the power
supply, right? There usual hum from the transformer is a bit loud, but
I have heard many synths with loud transformers, so I am not going to
do anything about that.
- All keys work again, although some needs to be cleaned properly
(they are intermittent)
- All encoders work, but one is way too slow, so I probably need a
complete new set of chips for that one
- Still a few buttons that don?t work properly (I have to push
repeatedly and/or hard to get it working), but I now know there is
nothing electronically wrong, just a tired switch underneath.

- The voice still missing puzzles me: I thought I traced the error to
a broken CEM3372 (the filter part works, but the VCA part seems to be
broken). So voice 6 is dead, but if I swap the CEM3372 between, say,
voice 5 and 6, then voice 5 becomes dead and voice 6 starts working.
So I got a fistful of CEM3372s (12 actually) from
Technologytransplant, but they don?t work, or the M12 doesn?t like the
fact that the "new" CEM is from another date stamp. Any ideas?

- I also started cleaning the synth - following the tip to clean up
the inside of the display window as well


Terje Winther
terje.winther@...

#780

Hi Terje,
?
Nice work on the M12. ?

--- On Wed, 4/14/10, Terje Winther <terje.winther@...> wrote:

- I found a strange repeating ripple of approx. 100 - 150 mV from the
power supply. It looks (on the scope) like two ripples rather close,
then an interval, and then the two ripples repeat again, all
microseconds apart. I?ve read in the archives that this could be
enough to throw off the auto-tune process, so I better recap the power
supply, right?When I posted that, I should have stated low frequency (60 Hz) ripple
usually seen with a voltmeter. If you are using a scope you will see
lots of digital noise on the rails from the 30 Khz switching power supply
output. ( 1/30 KHz = 30 uS ) I think this is what you are seeing.
And it is normal and too high a frequency to be heard.
I would be willing to bet the tuning errors are caused by the
Coupling Caps at the output of each voice. 2.2 uF 50VDC is the value
PC board reference number Cx49  ( x = Voice number).

Not that recaping the power supply is a bad idea. It would be good in the long run, however the coupling caps are the more likely culprit.


- The voice still missing puzzles me: I thought I traced the error to
a broken CEM3372 (the filter part works, but the VCA part seems to be
broken). So voice 6 is dead, but if I swap the CEM3372 between, say,
voice 5 and 6, then voice 5 becomes dead and voice 6 starts working.
So I got a fistful of CEM3372s (12 actually) from
Technologytransplan t, but they don?t work, or the M12 doesn?t like the
fact that the "new" CEM is from another date stamp. Any ideas?That is strange. I do not know of anyone who has puchased from Tech Transplant, so I have no track record to work with there.

some thoughts:

Will a newly purchased 3372 work in one of the other voices? I supose there could still be something wrong with voice 6.

Did you try retuning VCF/VCA's after changing out the part? In theory
this would calibrate out any differences between individual chips.

It does not make any sense that a newer/different date chip would not work at all. More likly there would be tracking errors or offsets.

Best Luck

Karl Schmeer

#1728

Karl Schmeer

You recently answered a post regarding a Matrix 12.
In that response, you stated that the chip- 3372 could still be found.

If you have some info on where I can find these chips, please RSVP.
I also have a dead voice in my Xpander and would love to replace it.

Thanks!

#1730

There's a guy who is local to me who sells chips and repairs synths.

I don't know if he has the chips you need.

Let me see if I can find his wesbsite

Show quoted text

On Thu, Apr 8, 2021 at 3:05 PM keysynths <keysynths@...> wrote:

Karl Schmeer

You recently answered a post regarding a Matrix 12.
In that response, you stated that the chip- 3372 could still be found.

If you have some info on where I can find these chips, please RSVP.
I also have a dead voice in my Xpander and would love to replace it.

Thanks!

#1731

Appreciate it!

On Thu, Apr 8, 2021 at 6:48 PM TC <cappy2112@...> wrote:

There's a guy who is local to me who sells chips and repairs synths.
I don't know if he has the chips you need.
Let me see if I can find his wesbsite

On Thu, Apr 8, 2021 at 3:05 PM keysynths <keysynths@...> wrote:
Karl Schmeer

You recently answered a post regarding a Matrix 12.
In that response, you stated that the chip- 3372 could still be found.

If you have some info on where I can find these chips, please RSVP.
I also have a dead voice in my Xpander and would love to replace it.

Thanks!

Virus-free.

#1733

开云体育

EUR 49,-

My friend Karl Schmeer unfortunately passed away march 10, 2021 ...? ?

big loss,- also for Xpantastic !

R.I.P. Karl

P.

Am 09.04.2021 um 00:05 schrieb keysynths:

Karl Schmeer

You recently answered a post regarding a Matrix 12.
In that response, you stated that the chip- 3372 could still be found.

If you have some info on where I can find these chips, please RSVP.
I also have a dead voice in my Xpander and would love to replace it.

Thanks!

Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft.

#1734

Pe We

What are you talking about?

Karl just replied to this thread?

I'm sorry for your loss...

Show quoted text

On Thu, Apr 8, 2021 at 6:49 PM PeWe <ha-pewe@...> wrote:

EUR 49,-

My friend Karl Schmeer unfortunately passed away march 10, 2021 ...? ?

big loss,- also for Xpantastic !

R.I.P. Karl

P.

Am 09.04.2021 um 00:05 schrieb keysynths:

Karl Schmeer

You recently answered a post regarding a Matrix 12.
In that response, you stated that the chip- 3372 could still be found.

If you have some info on where I can find these chips, please RSVP.
I also have a dead voice in my Xpander and would love to replace it.

Thanks!

Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft.

#1736

His wife informed me same day (march 10).
Very sad !

Am 09.04.2021 um 05:14 schrieb TC:
Pe We

What are you talking about?
Karl just replied to this thread?

I'm sorry for your loss...

--
Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft.

#1738

His reply is dated April 8.

I’m very sorry to hear this.

Show quoted text

On Thu, Apr 8, 2021 at 8:54 PM PeWe <ha-pewe@...> wrote:

His wife informed me same day (march 10).
Very sad !

Am 09.04.2021 um 05:14 schrieb TC:
> Pe We
>
> What are you talking about?
> Karl just replied to this thread?
>
> I'm sorry for your loss...
>

--
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#1739

This is strange,- how comes ?

I still have the emails I got from his wife march 10 and 12,- the latter
describing what caused his death.

Am 09.04.2021 um 09:23 schrieb TC:
His reply is dated April 8.

--
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#1748
Edited

Karl's last post to this forum was on 10/08/20. (His last reply to this thread was actually 4/15/10.)

PeWe, please pass on the group's heartfelt sympathies and gratefulness.? He made more helpful contributions to the group than anyone. There's no way to count all the people that his expertise helped, but we know he's directly and indirectly responsible for saving many synths. And that means more music for more people to enjoy, thanks to him.