The Oberheim OB-SX has 2, 4, or 6 notes of polyphony depending on the number of 2-voice oscillator cards installed. It was meant to be a portable version of the OB-X and has the same sound. The 6-voice version had a list price of $3495 and the 4-voice was $2995.
The original version had 24 patch memories. Later versions had 48 or 56 patch memories. It used CEM3340 chips for its VCOs, CEM3320 for its filter, and CEM3310 for its envelope generators.
Year Released: 1980
Keyboard: 48 keys
Preset Patches: 24
Oberheim OB-SX Analog Synth ($2,500)