Oberheim OB-X

The Oberheim OB-X is an analog polyphonic synthesizer first commercially available in June of 1979 . It was the first Oberheim synthesizer that was created with internally pre-wired modules (albeit still mostly discrete circuits) and not with the earlier, unwieldy S.E.M.s (Synthesizer Expander Module). Because of this, it was more functional for live performance, and more portable. It was hurriedly introduced to compete with competitor Sequential Circuits' Prophet-5, which took the industry by storm during the prior year. While the OB-X had moderate success in the limited numbers produced (aprx. 800 units), the design was quickly updated and streamlined with the OB-Xa; the OB-X being discontinued in 1981.

Originally, the "X" in OB-X, stood as a variable for the number of voice-cards - thus, polyphony - installed. Whereas earlier Oberheim modular systems would require multiple S.E.M.s to achieve polyphony, the OB-X condensed the S.E.M. down onto a single printed circuit board called a "Voice Card". Using this method, along with the Z-80 microprocessor to program the cards, the OB-X was far less laborious to program than it's ancestors. It came in four, six, and eight-voice models. The starting price for the base model of only 4 voices of polyphony was a steep US$4,595. Besides the generous polyphony, each OB-X came with a memory capable of holding 32 user-programmable presets, along with polyphonic portamento, and polyphonic sample and hold. Also, a first for Oberheim's polyphonic range were the "paddle" levers for pitch and modulation. This was Oberheim's answer to the then standard "wheel" style controls seen on the Sequential Circuits Prophet-5. The OB-X would be used by artists such as Nena, Rush, who used it extensively on Moving Pictures and Signals, Queen, being the bands first Synthesizer to appear on an album, Prince, who swore by the Oberheim OB line, and Jean Michel Jarre who used it for it's massive brass-type sounds. The OB line of Synthesizers developed and evolved even after the OB-Xa with the OB-8, and finally the Matrix series of synthesizers.

SonicProjects have created a VSTi emulation of the OB-X, for Windows and Mac platforms called the OP-X, with near-identical sounds to the hardware version. Widely praised as the most accurate emulation of an Analog Polysynth, SonicProjects include multiple versions of the OP-X including two "Pro" versions.