Moving "Iron" Generator
A diamond stylus tracing the average record groove will experience accelerations of up to one thousand gravities. This means that in a moving magnet design the permanent magnet is subjected to similar accelerations and if its mass is too large its inertia will result in poor transient response, distortion and mis-tracking of the stylus. The 2000 series cartridges use a fixed magnet design so that the mass of the magnet is completely isolated by the compliance of the cartridge suspension and a much smaller and lighter iron/nickel alloy tube can be used instead. Attached to the cantilever, the alloy tube is used to perturb the stationary magnetic field provided by the large fixed magnet and thus provide the changing magnetic flux necessary to generate the signal voltage in the coils. Modern samarium cobalt magnets have a super high energy output and so a much lighter magnet can be employed than ever before giving the completed assembly a similar mass to traditional moving magnet types. In this way the cartridge enjoys the convenience and flexibility of a traditional moving magnet design with a replaceable stylus block and a high output compatible with standard MM input stages. At the same time it enjoys some of the refined sound and detail retrieval previously only available from more costly moving coil designs.
