Fidelity Research Cartridge
Fidelity research's MC44 cartridge is an advanced moving-coil cartridge incorporating a smaller version of the cross armature used in other cartridges in the Fidelity Research lineup. Moving-coil cartridges are traditionally designed with heavy, square armatures. FR's advanced design gives the armature of the MC44 a mass 40% less than that of conventional armatures. Normally, this mass saving would be utilised by giving the coils more turns and thereby increasing the output of the cartridge; but other features of the MC44's design have made this unnecessary. In fact, we have been able to reduce the number of turns of the coils by 10%, achieving a further mass reduction, while maintaining the high output of the cartridge. The low mass of the MC44 gives it the advantage of extremely low impedance - a value of 2.7 ohms, considerably less than the 3 ohms of usual low-impedance cartridges.
The stylus used in a cartridge has a considerable effect on the total equivalent tip mass. The stylus of the MC44 is a 'refined-contact' super-elliptical nude diamond, with a slim design 67% thinner than conventional styluses. The cantilever, made of hard, rigid, tapered aluminium alloy, weights only 63% of the cantilevers used in other Fidelity Research moving-coil cartridges.
The lighter armature, coils, stylus and cantilever of the MC44 give it an extremely low equivalent tip mass of 0.35 milligrams. This has enabled us to use a softer rubber compound in the damping system, increasing the dynamic compliance to the very high value. This higher dynamic compliance gives the MC44 better tracking ability than most other comparable cartridges.
High tracking ability is important; but if the cartridge has a low output, the signal-to-noise ratio will be low, and the total sound quality will be poor. To prevent this, FR used a high-strength samarium cobalt magnet and constructed the pole pieces in such a way that the magnetic flux is concentrated directly in front of the cross armature, resulting in a high output of 0.20 mv.