Optigan Disc Classical Guitar 4/4 No Sleeve

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Optigan Disc Classical Guitar 4/4 Missing Picture Sleeve Inner Sleeve Only Condition Good. The Optigan is an electronic keyboard instrument designed for the consumer market back in the 70's. The name stems from the instrument's reliance on pre-recorded optical soundtracks to reproduce sound. The Optigan's playback system functioned much like the storage and reading of an optical soundtrack as was used in motion pictures, using a light bulb to energize a row of photodiodes on the opposite side of spinning, 12" diameter clear plastic film discs (officially referred to as "Program Discs") encoded with fifty-seven concentric optical tracks. The system then translated the analog waveforms on the disc to an audio signal.