Teldec Mini Disc
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Sony's Mini Disc was slow to catch on in Europe. AEG-Telefunken's Mini Disc failed before it even reached the market.
The German MD was a mechanical goove-in-stylus digital audio disc that built on TeD, the grooved video disc developed in the sixties by Teldec, Telefunken's joint venture with Decca.
Like TeD, Mini Disc went back to Edison's original technique of vertical or hill and dale modulation, which packs the grooves very tightly to increase playing time. Whereas TeD was a flimsy disc, MD used rigid plastics in a protective caddy. The 13.5cm disc stored an hour of stereo on each side, sampled at 48KHz with 14 bit linear PCM coding. The groove pitch was 1.66 microns, the same as optical CD, and the disc rotated at 250rpm.
A diamond stylus tracked the groove with a force 50 times less than for a conventional LP. The stylus could last 1000 hours, but had to be automatically re-polished between each play.
Telefunken demonstrated MD to a closed meeting of the international Digital Audio Disc Standardisation Committee in Tokyo in June 1980. Telefunken executives thought the day had been "a great success". The DAD committee members had judged MD hoplessly impractical but were intrigued by the technology.
MD was shown publicly at the Tokyo Audio Fair in October 1980. Telefunken went to New York that December and hawked the system round the major record companies including CBS, RCA and WEA.
In December 1980 the DAD committee backed CD. But Telefunken would not give up and showed Mini Disc at the Berlin Radio Show in the autumn of 1981. "The MD system covers all aspects of the future audio market", said a spokesman. But CD was launched in 1982/3 as the industry standard.