The Development of the Tape Recorder

Overview

A number of experimental sound recording devices were designed and developed in the early 1900s in Europe and the United States. Recording and reproducing the sounds were two separate processes, but both were necessary in the development of the tape recorder. Up until the 1920s, especially in the United States, a type of tape recorder using steel tape was designed and produced. In 1928 a coated magnetic tape was invented in Germany. The German engineers refined the magnetic tape in the 1930s and 1940s, developing a recorder called the Magnetophon. This type of machine was introduced to the United States after World War II and contributed to the eventual widespread use of the tape recorder. This unique ability to record sound and play it back would have implications politically, aesthetically, and commercially throughout Europe and the United States during World War II and after. Sound recording and reproduction formed the foundation of many new industries that included radio and film.

Background

Sound recording and reproduction began to interest inventors in the late nineteenth century, when several key technological innovations became available. Recordings required the following: a way to pick up sound via a microphone, a way to store information, and a playing device to access the stored data. As early as 1876 American inventor Alexander Graham Bell (1847-1922) invented the telephone, which incorporated many of the principles used in sound recording. The next year, American inventor Thomas Alva Edison (1847-1931) patented the phonograph, and German-American Emil Berliner (1851-1929) invented the flat-disc recording in 1887. The missing piece was a device to play back the recorded sounds.

The history of the tape recorder officially begins in 1878, when American mechanic Oberlin Smith visited Thomas Edison's laboratory. Smith was curious about the feasibility of recording telephone signals with a steel wire. He published his work in Electrical World outlining the process: "acoustic cycles are transferred to electric cycles and the moving sonic medium is magnetized with them. During the playing the medium generates electric cycles which have the identical frequency as during the recording." Smith's outline provided the theoretical framework used by others in the quest for a device that would both record and play the sound back.

In 1898 a Danish inventor, Valdemar Poulsen (1869-1942), patented the first device with the ability to play back the recorded sounds from steel wire. He reworked Smith's design and for several years actually manufactured the first "sonic recorders." This invention, patented in Denmark and the United States, was called the telegraphon, as it was to be used as an early kind of the telephone answering machine. The recording medium was a steel chisel and an electromagnet. He used steel wire coiled around a cylinder reminiscent of Thomas Edison's phonograph. Poulsen's telegraphon was shown at the 1900 International Exhibition in Paris and was praised by the scientific and technical press as a revolutionary innovation.

In the early 1920s Kurt Stille and Karl Bauer, German inventors, redesigned the telegraphon in order for the sound to be amplified electronically. They called their invention the Dailygraph, and it had the distinction of being able to accommodate a cassette. In the late 1920s the British Ludwig Blattner Picture Corporation bought Stille and Bauer's patent and attempted to produce films using synchronized sound. The British Marconi Wireless Telegraph company also bought the Stille and Bauer design and for a number of years made tape machines for the British Broadcasting Corporation. The Marconi-Stilles recording machines were used until the 1940s by the BBC radio service in Canada, Australia, France, Egypt, Sweden, and Poland.

In 1927 and 1928 Russian Boris Rtcheouloff and German chemist Fritz Pfleumer both patented an "improved" means of recording sound using magnetized tape. These ideas incorporated a way to record sound or pictures by causing a strip, disc, or cylinder of iron or other magnetic material to be magnetized. Pfleumer's patent had an interesting ingredient list. The "recipe" included using a powder of soft iron mixed with an organic binding medium such as dissolved sugar or molasses. This substance was dried and carbonized, and then the carbon was chemically combined into the iron by heating. The resulting steel powder, while still heated, was cooled by being placed in water, dried, and powered for the second time. This allowed the recording of sound onto varieties of "tape" made from soft paper, or films of cellulose derivatives.

In 1932 a large German electrical manufacturer purchased the patent rights of Pfleumer. German engineers made refinements to the magnetic tape as well as designing a device to play back the tape. By 1935 a machine known as the Magnetophon was marketed by the German Company AEG. In 1935 AEG debuted its Magnetophon with a recording of the London Philharmonic Orchestra.

Impact

By the beginning of World War II the development of the tape recorder continued to be in a state of flux. Experiments using different types and materials for recording tapes continued, as well as research into devices to play back the recorded sounds. Sound recording on coated-plastic tape manufactured by AEG was improved to the point that it became impossible to distinguish Adolf Hitler's radio addresses as a live or a recorded audio transmission. Engineers and inventors in the United States and Britain were unable to reproduce this quality of sound until several of the Magnetophons left Germany as war reparations in 1945. The German version combined a magnetic tape and a device to play back the recording. Another interesting feature, previously unknown, was that the replay head could be rotated against the direction of the tape transport. This enabled a recording to be played back slowly without lowering the frequency of the voice. These aspects were not available on the steel wire machines then available in the United States.

The most common U.S. version used a special steel tape that was made only in Sweden, and supplies were threatened at the onset of World War II. However, when patent rights on the German invention were seized by the United States Alien Property Custodian Act, there were no longer any licensing problems for U.S. companies to contend with, and the German innovations began to be incorporated into the United States designs.

In 1945 Alexander Poniatoff, an American manufacturer of electric motors, attended a Magnetophon demonstration given by John T. Mullen to the Institute of Radio Engineers. Poniatoff owned a company called Ampex that manufactured audio amplifiers and loudspeakers, and he recognized the commercial potential of the German design and desired to move forward with manufacturing and distributing the Magnetophon. In the following year he was given the opportunity to promote and manufacture the machine in a commercially viable way through an unusual set of circumstances.

A popular singer, Bing Crosby, had experienced a significant drop in his radio popularity. Crosby attributed his poor ratings to the inferior quality of sound recording used in taping his programs. Crosby, familiar with the Magnetophon machine, requested that it be used to tape record a sample program. He went on to record 26 radio shows for delayed broadcast using the German design. In 1947 Bing Crosby Enterprises, enthusiastic about the improved quality and listener satisfaction, decided to contract with Ampex to design and develop the Magnetophon recording device. Ampex agreed to build 20 professional recording units priced at $40,000 each, and Bing Crosby Enterprises then sold the units to the American Broadcasting Company.

In the film world, Walt Disney Studios released the animated film Fantasia. This film used a sound process called Fantasound, incorporating technological advances made in the field of sound recording and sound playback. These commercial uses of the magnetic tape recording devices allowed innovations and expansion in the movie and television-broadcasting field.

By 1950, two-channel tape recorders allowing recording in stereo and the first catalog of recorded music appeared in the United States. These continued advancements in tape recorder technology allowed people to play their favorite music, even if it had been recorded many years prior. Radio networks used sound recording for news broadcasts, special music programming, as well as for archival purposes. The fledgling television and motion pictures industries began experimenting with combining images with music, speech, and sound effects. New research into the development and use of three and four-track tape recorders and one-inch tape was in the works as well as portable tape cassette players and the video recorder. These new innovations were possible and viable because of the groundwork laid by many individuals and companies in the first half of the twentieth century.

LESLIE HUTCHINSON

Further Reading

Eargle, John. Handbook of Recording Engineering. New York: Chapman & Hall, 1996.

Millard, A. J. America on Record: A History of Recorded Sound. London: Cambridge University Press, 1995.

Moylan, William D. The Art of Recording: The Creative Resources of Music Production and Audio. Lowell, MA: University of Massachusetts Press, 1993.