At around the same time the Blattnerphone was introduced, other German researchers were perfecting a method of coating thin celluloid tape with iron oxide particles. This arrangement was not only much lighter and more compact than solid steel or wire, but the particles were actually more easily magnetized. After the Second World War, American manufacturers introduced copies of these German Magnetophons. While the first such device, the Brush BK-401 was designed as a home recorder, broadcasters and record companies soon began to buy large numbers of such professional models as the Magnecorder PT6 and the Ampex 300. Not only were these machines capable of very high fidelity and low noise performance, they could record long passages without interruption. Moreover, errors could be corrected or diverse programs assembled simply by splicing in the desired material. Beginning in the 1950s, recording engineers also discovered that by overdubbing or by recording on multiple tracks, they could assemble an ideal performance without the need for recording an entire ensemble in a single, flawless, nerve-racking take.

Fig. 26. Magnecorder PT6A (841209) was widely used by radio broadcasters from 1948 to 1960. (CSTM)

Fig. 27. Ampex 300 (840005), the standard for record mastering, 1948 to 1952. (Peter Lindell/CSTM)