1981 Oberheim OB-XA 8 Voice Analog Synthesizer SN 813061

via this auction

Pics of the inside below.

"Overall this classic Oberheim synth is in good condition with minor scratches in the finish on the top of the unit and minor scuffs in side panels. The top panel hinge is in great shape and opens smoothly. While none of the original OB-Xa's have MIDI, unless otherwise having been modified. The OB-Xa is a classic and fat analog machine. It will give you thick analog pads and drones, punchy bass and cyclic analog effects.

95% of all functions have been tested and are functional. All control functions of the face of unit have been tested and are all functional. Footswitch/Pedals, Cassette Interface, and Computer interface input/outputs have not been tested. We do not have the proper pedals, switches, and cables to test fully. The transpose buttons do not seem to function and need servicing. This keyboard was not in use for many years and some key contacts will need cleaning as they sometimes double hit."