78 rpm Phonograph & Transcription Digitizing
Early disc recordings were produced in a variety of speeds ranging from 60 to 130 rpm, and a variety of sizes. As early as 1894, Emile Berliner's United States Gramophone Company was selling single-sided 7-inch discs with an advertised standard speed of "about 70 rpm".
One standard audio recording handbook describes speed regulators, or governors, as being part of a wave of improvement introduced rapidly after 1897. A picture of a hand-cranked 1898 Berliner Gramophone shows a governor. It says that spring drives replaced hand drives. It notes that:
The speed regulator was furnished with an indicator that showed the speed when the machine was running so that the records, on reproduction, could be revolved at exactly the same speed...The literature does not disclose why 78 rpm was chosen for the phonograph industry, apparently this just happened to be the speed created by one of the early machines and, for no other reason continued to be used.
By 1925, the speed of the record was becoming standardized at a nominal value of 78 rpm. However, the standard differed between places with alternating current electricity supply at 60 hertz (cycles per second, Hz) and those at 50 Hz. Where the mains supply was 60 Hz, the actual speed was 78.26 rpm: that of a 60 Hz stroboscope illuminating 92-bar calibration markings. Where it was 50 Hz, it was 77.92 rpm: that of a 50 Hz stroboscope illuminating 77-bar calibration markings.
Prices include all necessary USB Drives or Discs
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