Tefifon

The Tefifon was a German audio format developed and manufactured by Tefi between 1936 and 1961. It utilized endless loop cartridges of grooved vinyl tape wrapped around a plastic core. These tapes, called "Tefi," were played on specially designed players. Unlike phonograph records or magnetic tape, the Tefifon's audio information was embossed into the tape itself.

The format offered a significantly longer playing time than phonograph records of the era, with some cartridges capable of holding several hours of music. This was a significant advantage, particularly for classical music and radio dramas. However, the audio quality was generally considered inferior to records, and the format ultimately failed to gain widespread popularity.

Several factors contributed to the Tefifon's lack of success, including its relatively high cost, the bulky size of the cartridges and players, and the emergence of higher-fidelity audio formats like the long-playing (LP) record and, later, magnetic tape cassettes. Despite its relatively short lifespan, the Tefifon remains a notable example of early attempts to create a convenient and long-playing audio format.