45worlds Forum - View Single Post - Varying Playback Speeds on Shellac Records (78 rpm, 80 rpm, 81 rpm, etc.)

Latest Posts » 78 RPM » View Topic

View Single Post

Topic: Varying Playback Speeds on Shellac Records (78 rpm, 80 rpm, 81 rpm, etc.)

13th May 2019, 7:22 PM
	xiphophilos Member since Dec 2013 3351 Points Moderator	Part 2 of the same post: a. Emil Berliner's first disc gramophones were wound by hand at somewhere between 60 and 100 rpm. The 7-inch discs lasted a minute or so and had low sound quality. Berliner and his assistant Fred Gaisberg realised that unless the speed was governed, the gramophone would never be more than a novelty. Gaisberg visited a young mechanic who was making clockwork machinery, hoping to use it for sewing machines. This machinery was never successful in sewing machines, but was ideal for gramophones, and it rotated at 78 rpm. The mechanic, Eldridge Johnson, became a millionaire. Columbia made all its discs to run at 80 and HMV had its pioneer recordings produced between 68 and 92 rpm with the key of the piece marked on the label. You then tuned it on your own piano, using the gramophone's governor. These speeds all gradually settled into the standard of 78. When talking pictures first arrived in the late 1920s, the sound was recorded separated on discs and had to be synchronised by the projectionist at each showing. Every cinema projection room had a pair of projectors, each taking 1000-feet reels of film, whose running time was about 10 minutes. The projectionist switched projectors after each reel. Ideally, this meant that the sound should last 10 minutes as well, as it would be impossible to synchronise a sound changeover in midreel. At the time, however, a 12 inch 78 rpm record lasted for only about 4 minutes, so the Vitagraph company simply slowed down the 78 until it lasted 10 minutes and recorded all their masters on that, starting each disc in the middle, as it was easier to drop a needle there than the outer edge. This new speed was 33 1/3 rpm, adopted for other records in the late 1940s when Columbia introduced its first vinyl, long-play discs with microgrooves, giving a play time of about 30 minutes on each side. However, the long-play disc wasn't particularly suitable to popular music, as the public wanted its records as singles with good sound quality even at high volumes. RCA Victor came up with a 7-inch vinyl disc with microgrooves, rotating at 45 rpm, a speed chosen specifically to make the most of the music, unlike 78s or 33 1/3s. And does no one remember the 16s? ROGER WORSLEY Haverfordwest Pembrokeshire