Vintage Synth Repair

Hello!

I have a Matrix6R whose first voice plays about one and a half times 
as loud as the other five voices. Is this probably a VCA or VCF 
trimpot in need of adjustment? ..or a problem with an op-amp. . ? 
or. . ?


I love these sounds and can't wait to get back to using them..
Please let me know if you have any suggestions !


-robert scott
[ quiet_channel@... ]

If the main vioce chip is removable, you can switch between the bad 
voice and a good one and see if the problem "moves" to the other 
voice... this way you can know whether it is the chip or not.


--- In vintagesynthrepair@yahoogroups.com, "robert andrew scott" 
<quiet_channel@...> wrote:
>
> 
> 
> Hello!
> 
> I have a Matrix6R whose first voice plays about one and a half 
times 

> as loud as the other five voices. Is this probably a VCA or VCF 
> trimpot in need of adjustment? ..or a problem with an op-amp. . ? 
> or. . ?
> 
> 
> I love these sounds and can't wait to get back to using them..
> Please let me know if you have any suggestions !
> 
> 
> -robert scott
> [ quiet_channel@... ]
>

Hi Robert !

The Matrix has 6 voices and each complete voice ( VCO / VCF / VCA ) is
integrated in only one chip ( like ion the Matrix 1000 ).
The chip(s) are labeled CEM 3396 and most important, - these are the "wide
body" versions in a Matrix 6 which unfortunally are more expensive and
harder to find compared to the standard version in the Matrix 1000.

How often a voice plays is dependent on what keyboard assign mode is
programmed in the patch(es).

So, call up a patch, go to edit mode and set the voice / keybaord assign
parameter to "rotate".

Check which voice fails w/ case open, eventually there are leds w/ lit for
each voice on the circuitboard w/ is the home of the 6 voices.
If one is lit and this voice makes no sound, - this is the faulty one.
My Matrix 1000 has no leds, so I don\ufffdt know w/ the M6 .

If you don\ufffdt have leds, you\ufffdl have to check it by ear only and swap the
chips until you\ufffd\ufffdve found the faulty one.
Be very careful of electrostatic if you do this not to damage more chips.

From the Matrix-1000 Service (eventually you have a routine like this in the
Matrix 6 and the display shows the played voices) :

View the Voices as they are played:

1. press Selet button to get to "Ext Funct"
2. press 7 then Enter
3. press + button to display "1"
4. Press Enter

5. the display shows the voice as it is played

Reset:

1. Power Up while holding "Enter" button (EPROM Rev. is displayed too)

In most cases of voice failure, you have to replace one of these chips.

Senso at Vintage Planet http://www.vintageplanet.nl/index.html  has them
sometimes, or check chip for brains @ ebay.

cheers \ufffdn good luck...

PeWe

----- Original Message -----
From: gil_we
To: vintagesynthrepair@yahoogroups.com
Sent: Sunday, August 06, 2006 10:21 AM
Subject: [vintagesynthrepair] Re: Matrix6(r) first voice issue !! please
help ! (cross-posted)

Strange, I have one and never really used it.

You can always open it up and watch how it is designed.




--- In vintagesynthrepair@yahoogroups.com, "robert andrew scott" 
<quiet_channel@...> wrote:
>
> 
> 
> Hello!
> 
> I have a Matrix6R whose first voice plays about one and a half 
times 

> as loud as the other five voices. Is this probably a VCA or VCF 
> trimpot in need of adjustment? ..or a problem with an op-amp. . ? 
> or. . ?
> 
> 
> I love these sounds and can't wait to get back to using them..
> Please let me know if you have any suggestions !
> 
> 
> -robert scott
> [ quiet_channel@... ]
>