OBERHEIM SYNTH

Hi folks,

Many thanks to the people who helped out with WAV files of the factory
presets a few months back. I'm now trying to work out how old my OB-X
might be, as I think it's probably a pretty early one. It doesn't have
the name on top in a large OB-Xa style serif font, rather a small name
in a distinctly blocky font above the keyboard. It is also an original
four voice specimen, as confirmed by the Oberheim identity tag on the
back. It's serial number 793401, and I'm wondering if anyone knows how
to date an OB-X based on this information.

Regards,

Chris