Increased Noise Reduction by Delay Networks

This paper describes a new method of obtaining increased signal-to-noise ratio in optical sound film recording. This is done by increasing the noise reduction and is made possible by the use of delay networks which delay the application of sound currents to the modulator until after the noise-reduction-bias current has been partially canceled. Noise-reduction settings as high as 30 db have been tried with good success and settings of 15 db have been used in regular production.