Oberheim Matrix 6 (and fixes)

Harry Bissell harrybissell at prodigy.net
Sun Nov 28 21:29:59 CET 1999


The Matrix 6 and 12 are the same or very similar. The Xpander is a very different
beast with 15 or so filter modes etc. Though I have heard that the Xpanders env
gens were a little slow...

I wanted the Xpander but couldn't afford it. I've had the Matrix 6 and it was
good sounding, but tended to go off into the weeds on power problems. If it was
for live use I'd get an uninteruptable power supply for it.

The problem is the memory voltage system... the processor runs on 5V but the
memory is a diode drop below (4.3V) so as the voltage goes down there is a good
chance the memory will get corrupt before the processor knows its time to go
"nitenite".

A simple improvement is to use a low drop shottkey diode (In5817) which have a
much lower forward drop (at the expense of higher rebverse leakage at high
temps...) so the memory gets about 4.7 volts...

The Right FIX is to boost the 5V supply to 5.7 volts (usually a diode added to
the voltage reg will do this, then add a diode in series with the out of the
regulator to drop the volts back to 5V. Then add a similar diode to supply the
memory. This way while running the supplies are both 5V and the memory backup
voltage is isolated. Why didn't they do this at the factory I'll never know...
its only two more diodes...
This is major surgery... not for the faint of heart. I did the easy mod above and
it made an 80% improvement.

I have the Matrix 1000... Its great and never flaked out. With software you can
edit it... or load programs from a Matrix 6.  I'd go for this one !!!

:^) Harry


Hallgeir Helland wrote:

> Rob wrote:
> >
> > Both sound really good though. Matrix 6 goes for about 450, and the matrix
> > 1000s are still being sold in limited quantities last time I tried to get
> > one.. they go for about 300-400 used.. I will eventually get off of my duff
> > and get one.
>
> Hi,
>
> Does the Matrix 6 do the same (and sound the same) as
> the Matrix 12 and the Xpander? If so, I'm getting mine!
>
> thanks,
> Hallgeir
>
> btw: any Lowther owners onlist?
>
> --
> .,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.
>  Hallgeir Helland   hhelland at mailandnews.com
>     Evlogia          http://fly.to/evlogia
> '¨'¨'¨'¨'¨'¨'¨'¨'¨'¨'¨'¨'¨'¨'¨'¨'¨'¨'¨'¨'¨'¨'




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