
via
this auction
"-one OBX synthsizer
-two "OBX Factory Patches" cassettes dated to 10/80 and 12/79
-a stack of paperwork:1979 OBX manual, 1981 OBXa manual, documentation of the mods, service receipts, and a stack of schematics/repair documents
It has some mods/upgrades that were professionally installed long ago (back when they were new and state of the art):
-JL Cooper Patch 96 memory upgrade (all patches work, some are factory, some are not)

-the "release" control for the amplifier's ADSR has been changed to a "program volume" control, giving the ability to balance different program volumes to each other
Unit has all eight voices installed!"
inside an OB-Xa