1900, the tape recorder invented by Paulson was exhibited at the Paris Expo. Because this tape recorder records on a steel wire, it has unique advantages compared with the phonograph. At the Expo, it was favored by people.
However, magnetic recording uses high-quality steel wire and steel belt, which is very heavy and inconvenient to use. Therefore, in 1930, Freuima of Germany proposed a new scheme, that is, paper tape or plastic tape coated with iron powder replaced steel wire or steel belt. After six years of hard work, Ma Rui developed a tape recorder from 65438 to 0936. Compared with tape recorder, this kind of recorder has clear sound, convenient use and low price.
Marvin made a wire recorder with new principles in 1937. It uses a complete magnetic ring as the magnetic head, and the steel wire passes through the coil and keeps a certain distance from the magnetic ring, so that the air around the steel wire can be used for recording. Because this air gap is surrounded by the surface of the steel wire, it is uniform.
The performance of this tape recorder is much better than that of the previous one. Vivid sound and beautiful sound quality. Marvin's cousin was released by this tape recorder after being addicted to singing. People joked: "The singing level of this' amateur singer' has improved many times in an instant."
Since then, Marvin has improved this tape recorder and made a light and thin plastic tape. Since then, he also invented the "hi-fi multi-channel stereo" playback device.