Duo-Trac 'Cell-o-Phone' optical tape player, c 1936.
© Science Museum / Science & Society Picture Library
Tape player made by the British Ozaphane Company as a smart domestic alternative to the gramophone. A contemporary brochure describes the machine as using 'a beam of light instead of a needle - a ribbon instead of a disc. Six to sixty minutes of uninterrupted programme at the turn of a switch'. Recordings were made in the form of optical traces on a 4 mm cellophane 'ribbon' played by being pased between a lamp and a photo-electric cell. Although a commercial failure, the Cell-o- Phone pre-dated magnetic tape by ten years. Shown open.