Multichannel record disc recording system

摘要

A multichannel record disc recording system comprises: a circuit for shaping sum and difference signals from multichannel signals, angle modulating the difference signal, multiplexing the sum signal and the angle-modulated difference signal, and recording the resulting signal on a record disc. A first level control circuit, in the transmission system for the sum signal, operates to attenuate the high-frequency band of components of the sum signal when its level is at a high level. A second level control circuit, in the transmission system of the difference signal, operates to attenuate the middle-high frequency band of components of the difference signal when its level is at a high level. The first level control circuit attenuates the level of the sum signal to prevent an admixing of the higher harmonics of the high frequency component of the sum signal into the band of the angle-modulated difference signal. The second level control circuit attenuates the level of the difference signal to prevent an overdeviation due to overmodulation of the angle-modulated difference signal.