A

David

Darling

phonograph

phonograph

Cutaway of a phonograph (record deck) with belt drive and anti-skate pickup arm.


A phonograph, also called a record player, is an instrument for reproducing sound recorded mechanically as modulations in a spiral groove. It was invented by Thomas Edison (1877), whose first machine had a revolving grooved cylinder covered with tinfoil. Sounds waves caused a diaphragm to vibrate and a stylus on the diaphragm made indentations in the foil. These could then be made to vibrate another stylus attached to a reproducing diaphragm. Wax disks and cylinders soon replaced tinfoil, then, when by etching or electroplating metal master disks could be made, copies were mass-produced in rubber, wax, or plastic.

 

The main parts of a record player are the turntable to rotate the disk at constant angular velocity; the stylus, which tracks the groove and vibrates with its modulations; the pickup or transducer that converts these by the piezoelectric effect or electromagnetically into electric signals. See also amplifier and the loudspeaker.