[sdiy] Oberheim Xpander help!

[Jay Schwichtenberg]

Daniel,

Ohhh Yaaah!

IMO Oberhiem stuff has a pretty high problem rate. Out of the 8 units I have
had (2 - Xpanders, M12, M6, 3 - M6R & M1000) 4 have had problems. Mainly the
Xpanders, M12 & M6.

Anyways.

If you look at the schematics they feed the VCO back into the uP for the
tuning. Didn't look into the VCF and VCA calibration.

With the Xpanders and M12 there has been 2 major problems. First the plastic
or vinyl overlay that is on the case shrinks and binds the buttons. Every so
often I have to take the things apart and cut and file away the
plastic/vinyl so the buttons don't bind. Second big problem is sockets. They
socketed all the chips and I have had major problems with that. A lot of
times just reseating the chips helps but sometimes I've had to replace the
sockets. Be careful when pulling the chips out I had one VCO socket's pins
come out when I pulled the chip to reseat it. Right now my Xpanders and M12
need a major overhaul because the caps are starting to go. I'm getting a lot
of popcorn noise.

So I'd reseat some chips and cables. If that doesn't work I'd expect CMOS
and caps.

Jay


> -----Original Message-----
> From: owner-synth-diy at dropmix.xs4all.nl
> [mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of Daniel Araya
> Sent: Wednesday, September 03, 2003 7:47 AM
> To: synth-diy at dropmix.xs4all.nl
> Subject: [sdiy] Oberheim Xpander help!
>
>
> Hi,
>
> I have a friend that has bought an Oberheim Xpander with a problem: one
> of the voices doesn't work and the processor seems to know this because
> it never plays a "silent" voice. He tells me that he gets errors during
> autotune too. Anyone seen this before?
>
> And secondly; Does anyone have the EPROM-images for the latest version
> of the OS for the Xpander?
> These are needed (I think);  Main Processor: 1.2 and Voice version:
> 1.4
>
> We have the servicemanual with the schematics but I thought it would be
> best to ask you guys before we start digging around in the machine!
>
> Best regards
>
> /Daniel Araya
>