Philips Cassette Recorder Modified For Pulse, Speed and Monitor

Part of collection of amateur sound synchronising equipment: Philips cassette recorder modified for pulse, speed and monitor, 1965-1970.

The recorder has also been modified so that the running speed of the tape can be varied in order to maintain close synchronization with picture on playback and the audio track can be listened to during recording. The usual process of making a sound film involves shooting the film on a camera and recording the sound separately on a sound recorder. A vital aspect of this is that there should be a means of close synchronization between film and sound that is maintained throughout the editing and sound mixing processes until the picture and sound are combined on the final projection print. In professional film production at this period this was achieved by recording a series of reference pulses from the camera motor onto a sound track alongside the audio track. This reference or synchronising track then governed the speed of the tape machine when the audio was re-recorded onto sprocketed magnetic film prior to editing the film.