The Tefifon is an audio player that uses cartridges containing plastic tape with a vertical arrangement of grooves representing sound. It is a branch of analog audio technology that shares some characteristics with other, better-known devices such as the phonograph or the 8-track tape cartridge. The Tefifon combines these developments in novel ways, introducing features that were lacking in other technologies of the era. Like the later 8-track cartridge, which became popular in the United States just as the Tefifon was losing ground, the Tefifon employs an endlessly looping tape, coiled around a mount in the center of the cartridge. However, the Tefifon relies on the mechanical storage of vibrations in a groove, and thus follows a line of technological development that goes back to the earliest sound-reproducing media of the nineteenth century, whereas the 8-track tape employs magnetic recording, which links it to the majority of today’s storage media, including computer hard drives.

The Tefifon was developed by Karl Daniel, who presented his first machines based on a similar concept, the Tephifon and the Teficord, in 1938. These devices were also used in Germany during World War II to store intercepted radio transmissions; the phonograph was used for similar tasks by the BBC Monitoring Service. The company that made and sold the Tefifon, the Tefi Werke in Cologne, engaged in an active and sustained promotion campaign, with a series of advertising brochures entitled Tefi Illu and styled as an entertainment magazine.

In the Tefifon tape player, the cartridge holding plastic tape with a vertical arrangement of grooves is inserted into the player, feeding the tape into the mechanism. Playback is started by turning on the device and positioning the needle on the tape.

Video on the history and technology of the Tefifon, made by Christina Dörfling and Ingolf Haedicke at the Media Archaeological Fundus of the Humboldt-Universität zu Berlin