78 rpm Records | Gramophone Records | Phonographs

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" discs with an advertised standard speed of "about 70 rpm".

By 1925, the speed of the record was becoming standardised at a nominal value of 78 rpm (Revolutions Per Minute). However, the standard was to differ between countries with their alternating current electricity supply running at 60 cycles per second (now Hertz) and the rest of the world. The actual 78 speed within 60-cycle countries was 78.26 rpm, being the speed of a 3600 rpm synchronous motor reduced by 46:1 gearing. Throughout other countries, 77.92 rpm was adopted being the speed of a 3000 rpm synchronous motor powered by a 50 Hz supply and reduced by 77:2 gearing.