MORE MUSIC MAGIC

New Zealand Herald, Volume LXXV, Issue 23109, 6 August 1938, Page 9 (Supplement)

MORE MUSIC MAGIC

New Gramop In Wh A Beam Takes the Place of a N

A N entirely novel gramophone has r\ been invented and is now on sale in England. It uses a beam of light instead of a needle, and because there is no needle there is no scratch. Moreover, the record is of such a character that an hour's entertainment can be enjoyed from a single one without further adjustment. A symphony can bo played right through without interruption. Electric Waves The machine . has been called the Cell-o-Phone because it utilises the photo-electric cell. The instrument works in very much the sanio way as the sound-system of tho talking films. In the recording the sound is changed into light; and in reproduction tho light is changed back into sound. Hero is the process. When we speak or make music we set up waves in the atmosphere. These waves vary in sizo and shape' according to the nature of

tho original sounds, and radiate in all directions. When directed into a microphone these varying waves are translated into correspondingly varied electric waves Or impulses. These electrical .impulses are made to oscillato mirrors which throw light upon a sensitivo moving film. The areas of light projected, and consequently tho shapes recorded on tho film, vary according to tho electrical impulses. They make zigzag shapes on tho sound track, which is a ribbon about a fifth •of an inch wide. Tho ribbons aro wound on reels. That is how tho record ribbons are made. Now for the reproduction. Easily Operated The reproducing instrument (the coll-o-phono) simply reverses the previous process. The sound track ribbon, with its varying black and white shapes, is unwound in front of a powerful lamp, so that continually varying areas of light pass through the track and play upon a light-sensitive photo-clectric cell.

This cell translates the light back into varied electrical impulses, which are then amplified and applied to the cone of the loud-speaker. Thus animated, the loud-speaker sets up vibrations in the atmosphere, or in other words, sounds, which are the same as the sounds originally recorded. This seems complicated, but the instrument is operated without trouble. Tho record ribbon of this gramophone corresponds to the sound strip that runs side by side with the tiny pictures of the film. In both cases sound is reproduced as light and then turned back into sound.