The Physics
An encyclopedia of scientific essays

Angular Speed of a Phonograph Record

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Bibliographic Entry Result
(w/surrounding text)
Serway, Raymond A. & Jerry S. Faughn. College Physics Fifth Edition. Orlando: Harcourt Brace, 1999: 211. "… tangential acceleration of a bug on the rim of a 10.0 inch diameter disk if the disk moves from rest to an angular speed of 78 rpm" 78 rpm
Funk and Wagnalls New Encyclopedia. Funk & Wagnalls: 376. "… is made to rotate on the turntable at constant speed, usually 33.3, 45, or 78 revolutions per minute (rpm)." 33.3, 45, 78 rpm
Rosenthal, Murray P. How to Select and Use Record Players. Hayden, 1979: 26. "Because it is designed to work with records not been previously encoded, the Burwen System is of particular interest to owners of old 78 rpm records." 78 rpm
Gelatt, Roland. Fabulous Phonograph: From Edison to Stereo. Appleton Century, 1955: 66. "From 1900 to 1925 it hovered between 74 and 82 revolutions per minute, then became stabilized at 78 rpm with the introduction of electrically powered turntables. The synchronous motor ran at 3600 rpm. With a 46:1 gear, this produced a speed of 78.26 rpm, which became the standard." 78.26 rpm
Taylor, Andy. Installing 3-Speed Motor in 78-RPM Phonograph. Mechanical Music Digest. 8 August 1999. "I installed the turntable wheel and powered up the motor: it worked in the 78, 45 and 33 rpm positions." 33.3, 45, 78 rpm

In 1877, Thomas A Edison created one of the first recording musical devices, the phonograph, which is also known as the record player. The phonograph is used to replay sounds that are recorded on a disc or cylinder. A phonograph that uses discs is called a gramophone and was invented by Emile Berliner in 1887.

The phonograph is made up of a turntable and a tonearm. An amplifier and a loudspeaker are included in some, but not all, phonographs. The turntable rotates by an electric motor and this is where the record, or disc, is placed. The tonearm, a pivoted rod, has a needle, or a stylus, at the end that moves from side to side and vibrates which in return transforms into electrical signals that are then amplified to reproduce the sound through loudspeakers. Edison produced the phonograph to be used as a dictating device, but soon it turned into one of the most popular and important machines that were used for sound reproduction in the 1900s.

The disc may have three speeds at which it rotates: 33.3, 45, or 78 revolutions per minute (rpm). The original, standard speed for the disc is 78 rpm. This was so because the fidelity and playing time had to even out, so the sounds that were heard would be good in quality and not very short in playing time either. If the disc had a speed of 100 rpm, then the playing time would be very short, yet the sound would have been very good. If the speed of the disc was slower, such as 40 rpm, then the record would have played longer but the sound would have been very bad. In the early 1900s, the acoustic phonographs varied in speeds from 74 to 82 rpm. When the electrically powered turntables were introduced, the standard speed became 78.26 rpm. The 78 rpm discs were able to play for about four minutes and were about 10 inches in diameter. The records with the speed of 33.3 rpm were introduced in 1948 and their standard size was twelve inches in diameter. In 1949, discs with the speed of 45 rpm were about seven inches in diameter. The records with the speed of 33.3 rpm were mainly used for classical music and long performances because of their long playing time. The 45 rpm discs were used for single songs because they had a shorter playing time.

If the phonograph was not created, many of the great musicians and singers that we know today would have not been known at all and their music and voices would not be remembered or heard by future generations. Also, the phonograph was able to expand the appreciation of music in the home because the discs could be used over and over. Many people were able to hear different types of music time and time again because of the phonograph. Through the years and decades, the phonograph has improved in quality, such as in sound. Today, CD players are used in homes instead of the phonograph, but if it were not for the phonograph, we would not have CD players today.

Alexandra Grosman -- 2000

Bibliographic Entry Result
(w/surrounding text)
Peter Copeland, George Brock-Nannestad, Roger Worsley. "Last Word Archive: Spins Doctored."New Scientist. "The size of the stylus effectively determined the size of the grooves in a record and the recordable frequency range limited by this groove size determined a speed between 70 and 90 rpm …. Standardisation did not begin until 1912 …. They settled on the average (or possibly the median) of these tests, which turned out to be 78 rpm." 70โ€“90 rpm
78 rpm
"The 45 rpm speed was the only one to be decided by a precise optimisation procedure (by RCA Victor in 1948). [A] speed of 45 rpm comes out of the formula." 45 rpm
"From 1894 to around 1930 there were many different record speeds ranging from 65 to 90 rpm …. The Victor company used 76 rpm for many years for its recordings but instructed buyers to reproduce at 78 …." 65โ€“90 rpm
76 rpm
78 rpm
"Emil Berliner's first disc gramophones were wound by hand at somewhere between 60 and 100 rpm …. This machinery was never successful in sewing machines, but was ideal for gramophones, and it rotated at 78 rpm …. Columbia made all its discs to run at 80 and HMV had its pioneer recordings produced between 68 and 92 rpm …. These speeds all gradually settled into the standard of 78." 60โ€“100 rpm
80 rpm
78 rpm
Terry Martini, Russ Firestone, A.G. Wilmore, Jon Miller. Last Word Archive: A Different Spin."New Scientist. "The 16 rpm record (or 16 3/4 rpm to be strictly correct) appeared in Germany, and later in the US, towards the mid-1950s. It was used primarily for "talking books", to take advantage of the increased playing time -- almost double that of a 33 1/3 long playing record." 16.75 rpm
33.3 rpm
"Recordings at 16 rpm were widely distributed by the US government in its "Talking Books for the Blind" programme. Their fidelity was about the same as a telephone, 300 to 3000 hertz, but [have] become obsolete since the development of cassette tapes." 16 rpm
"The 16 rpm discs were never common, but I remember a recording of some of Churchill's wartime speeches at this speed." 16 rpm
"I still have a prewar 16 rpm record. It's of a speech by Lenin about land ownership and the distribution of food on a Nardoni Diskotéka label made in Czechoslovakia."[I assume the author meant "Narodni Diskotéka".] 16 rpm

Editor's Supplement -- 2001