Tape Recorder

Verified Timeline

Lore & Background

The use of magnetic tape for sound recording originated around 1930 in Germany as paper tape with oxide lacquered to it. Prior to the development of magnetic tape, magnetic wire recorders had successfully demonstrated the concept of magnetic recording, but they never offered audio quality comparable to the other recording and broadcast standards of the time. This German invention was the start of a long string of innovations that have led to present-day magnetic tape recordings. Magnetic tape revolutionized both the radio broadcast and music recording industries. It gave artists and producers the power to record and re-record audio with minimal loss in quality as well as edit and rearrange recordings with ease. The alternative recording technologies of the era, transcription discs and wire recorders, could not provide anywhere near this level of quality and functionality. Since some early refinements improved the fidelity of the reproduced sound, magnetic tape has been the highest quality analog recording medium available. As of the first decade of the 21st century, analog magnetic tape has been largely replaced by digital recording technologies.

In Their Own Story

The earliest known audio tape recorder was a non-magnetic, non-electric version invented by Alexander Graham Bell's Volta Laboratory and patented in 1886 (U.S. patent 341,214). It employed a 3⁄16-inch-wide (4.8 mm) strip of wax-covered paper that was coated by dipping it in a solution of beeswax and paraffin and then had one side scraped clean, with the other side allowed to harden. The machine was of sturdy wood and metal construction and hand-powered by means of a knob fastened to a flywheel. The wax strip passed from one eight-inch reel around the periphery of a pulley (with guide flanges) mounted above the V-pulleys on the main vertical shaft, where it came in contact with either its recording or playback stylus. The tape was then taken up on the other reel. The sharp recording stylus, actuated by a vibrating mica diaphragm, cut the wax from the strip. In playback mode, a dull, loosely mounted stylus, attached to a rubber diaphragm, carried the reproduced sounds through an ear tube to its listener. Both recording and playback styluses, mounted alternately on the same two posts, could be adjusted vertically so that several recordings could be cut on the same 3⁄16-inch-wide (4.8 mm) strip. While the machine was never developed commercially, it somewhat resembled the modern magnetic tape recorder in its design.

Reader's Guide

Magnetic recording was conceived as early as 1878 by the American engineer Oberlin Smith and demonstrated in practice in 1898 by Danish engineer Valdemar Poulsen. Analog magnetic wire recording, and its successor, magnetic tape recording, involve the use of a magnetizable medium which moves with a constant speed past a recording head. An electrical signal, which is analogous to the sound that is to be recorded, is fed to the recording head, inducing a pattern of magnetization similar to the signal. A playback head can then pick up the changes in magnetic field from the tape and convert it into an electrical signal to be amplified and played back through a loudspeaker. The first wire recorder was the Telegraphone, invented by Valdemar Poulsen in the late 1890s. Wire recorders for law and office dictation and telephone recording were made almost continuously by various companies (mainly the American Telegraphone Company) through the 1920s and 1930s. These devices were mostly sold as consumer technologies after World War II. Widespread use of wire recording occurred within the decades spanning from 1940 until 1960, following the development of inexpensive designs licensed internationally by the Brush Development Company of Cleveland, Ohio and the Armour Research Foundation of the Armour Institute of Technology (later Illinois Institute of Technology). These two organizations licensed dozens of manufacturers in the U.S., Japan, and Europe. Wire was also used as a recording medium in black box voice recorders for aviation in the 1950s. Consumer wire recorders were marketed for home entertainment or as an inexpensive substitute for commercial office dictation recorders, but the development of consumer magnetic tape recorders starting in 1946, with the BK 401 Soundmirror, using paper-based tape, gradually drove wire recorders from the market, being 'pretty much out of the picture' by 1952.

Did You Know?

• The earliest known audio tape recorder was a non-magnetic, non-electric version invented by Alexander Graham Bell's Volta Laboratory and patented in 1886.
• The first practical tape recorder from AEG was the Magnetophon K1, demonstrated in Berlin, Germany in 1935.
• Magnetic recording was conceived as early as 1878 by American engineer Oberlin Smith and demonstrated in practice in 1898 by Danish engineer Valdemar Poulsen.
• The first wire recorder was the Telegraphone, invented by Valdemar Poulsen in the late 1890s.
• Consumer magnetic tape recorders starting in 1946 with the BK 401 Soundmirror gradually drove wire recorders from the market, being 'pretty much out of the picture' by 1952.