This Oberheim OB-SX is an “OB-X” style 4-voice, 56-program model and offers the legendary OB sound in a compact, lower-cost package. The voice design, and the sound of the synth itself, is somewhere between an OB-X and an OB-Xa. It would be a perfect instrument for a working recording studio where musicians will be coming in and out and just want to choose between a solid collection of pre-programmed sounds.

Though the front-panel programmability of the OB-SX is limited, MidiSoft.de has made a MIDI retrofit for it that simply plugs into the synth’s “computer interface” port (no installation/soldering required) and provides SysEx control of 40 synthesis parameters.

We believe in transparency when selling “pro serviced” synths so always include documentation of what services every synth we sell has received. Our approach to servicing vintage instruments entails both making sure every synth is working 100% now, and eliminating common failure points to preempt future issues.

This unit received the following services while it was here with us:

• Power supply update: replaced all smoothing capacitors, bridge rectifiers, and regulators
• Replaced all trimmer potentiometers on voice boards
• All panel controls cleaned
• Pratt Read keyboard action rebuild with leveling and new bushings, cleaned/polished bus bars and aligned key contacts
• Calibrated to factory standards
• Testing and 24+ hour burn in period

Cosmetic condition: very good, just a few very small scratches in the powder coat here and there