Oberheim Xpander -1984    Weight = ? Lbs. Number manufactured = ? MSR = $3995

User Manual: Far too Good or Manual Manor
Reset Proceedures: N/A
Operating System code: Lazy blue Octopus
MIDI or other control protocol: See manual
Software related Links:
Patches or knob settings: xpander patch collection
Circuit Overview: below
Scematics/Service Manual: fdiskc archive or Magnus' page or Manual Manor
Common Service Issues/Tips: below or Magnus' page
Parts Sources: Keys knobs semiconductors misc
Uncommon chips/modules used: CEM3372 VCF, CEM3374 dual VCO, HS3140C DAC
Modifications:press '6' when you get there :-)
General Info Links: Vintage Synth Explorer or matrix 12 page

Circuit Overview:
     Analog subtractive with digital control galore. 12DCO 6 voice. Identical to the Matrix 12 in a half voiced desktop version. This matrix 12 page here has a lot of good information; things you may want to know before attempting to troubleshoot these.

Service Tips:
     Troubleshooting should be similar to a lot of other analogs with digital control but..a lot more of it to deal with. I strongly recommend nobody who isn't quite experienced try to work on these synths in general. Not a piece to learn on. :-) The DAC chips have been known to be a problem and are not available commonly unfortunately. See alphaentek for a great page on this synth and other Oberheims.

NOTE: Regarding CEM3372 VCF's. We had a recent bit of experience trying to get these to work in Doug Terrebone's Prophet 600 and in one I had here. None of the stock I had would sound the same (not to mention that two I got from chipforbrains some time back were totally doa... bummer. Thought those were NOS!) They lacked the whispy overtones with Resonance all the way up in particular. THey were all "C" revision. The "B" rev's were in the P600's but Doug said he finally got in an AX80 that had Rev "C's" and those worked fine! Go figure! Anyway just beware that there is some variation in these chips.

You might find these people helpful who bought parts when Gibson offloaded them:
Phone: 760 246-3866
Fax: 760 246-3494
or 800 603-5427 if it still works (I checked..none of these are good anymore. Will update if I get some that are.)
Contact Sound Doctorin' if you need something I might have.