Convention Paper
A High Quality Moving Coil Cartridge of New Design
AES Convention 69 · Paper 1765 · May 1981
Abstract
In order to evaluate the newly designed MC cartridge it was necessary to develop a new measurement system. The main portion of the new measurement system consists of a bidirectional vibration exciter (stereo cutter head) and a specially designed driving circuit. This system can drive a cartridge though the stylus from signals of various waveforms at high levels. One can measure characteristics of the cartridge itself accurately because it is free from influence of the warp of a disc and the interaction between stylus and disc. The weight of the magnetic circuit of the new MC cartridge (PC-70MC) is only 0.9 g which is one-quarter that of conventional ones. The light weight of the cartridge, coupled with a low mass tone arm, enables the system to trace low frequency signals on a disc very faithfully. The cartridge has a high output voltage of 0.2 mV rms at a reference level of 3.54 cm/s, 45° peak at 1 kHz. Because of the high value of magnetic flux density produced by the 6-pole, 4-magnet structure, the equivalent mass of the moving system of 0.23 mg is about half that of conventional cartridges. As a result of the reduced equivalent moving mass, high trackability, and low harmonic distortion are obtained.
