ABSTRACT
Moving-coil (MC) cartridges are generally accepted to have a better tracking performance than moving-magnet cartridges because the moving element is a set of lightweight coils rather than a magnet which is inevitably made of a relatively dense alloy. There is much greater variation in impedance and output across the available range of moving-coil cartridges than for moving-magnet cartridges. Because MC cartridges can be modelled for noise purposes simply as their coil resistance, it is straightforward to calculate the best signal/noise ratio possible. The high cost of transformers means that there is a strong incentive to come up with an electronic solution to the amplification problem. The only thing that makes it possible to achieve a reasonable signal-to-noise ratio is that the very small signal comes from a very low source impedance. A final constraint on the attenuator is the need for low output impedances so the succeeding MM input stage can give a good noise performance.
