The Westrex Stereo Disk System

This paper describes the Westrex StereoDisk Recorder which records two stereophonic channels in a single groove with a single stylus. The axes of the two recordings are at 90 degrees to one another, each being at 45 degrees with the horizontal plane of the record. By use of appropriate input circuits, the vertical-lateral type of stereophonic record may also be recorded. The recorder utilizes the electrodynamic feedback features of the Westrex lateral recorder. The design features of the recorder are described and the performance is discussed. Data on channel crosstalk, intermodulation distortion, and frequency characteristics are given. The design features and performance of the complementary StereoDisk Reproducer are described, including the desirability of maintaining the same vertical tracking angle in both recorder and reproducer. This reproducer employs dual d´Arsonval movements resulting in an exceptionally faithful reproduction.