The design of a high-fidelity disc recording equipment

Section 1 of this paper outlines the present technique of disc recording and indicates briefly its principal advantages and disadvantages as compared with other systems of sound recording. Present practice and the existing degree of standardization are discussed as regards cutting speed, turntable speed, groove shape, groove spacing and disc dimensions. The magnitudes of the stylus amplitudes, velocities and accelerations normally involved are shown, and the considerations which govern the use of radius compensation and the choice of the optimum recording characteristic are discussed. Section 2 deals in a little more detail with some of the technical problems which were encountered in developing a high-fidelity disc recording equipment. The turntable drive and the various considerations which arise in mounting the cutter head are discussed. The design of a robust, high-fidelity cutter head is described and methods of making cue marks and of removing swarf while recording are outlined. A practical method of obtaining the required radius compensation is also discussed. Section 3 describes a high-fidelity disc recording equipment, and indicates the performance that may be obtained from it.