Goldring 2500 Moving Iron Cartridge
All Goldring 2000 series cartridges feature Moving Iron technology. This lends them the high levels of detail associated with more expensive moving coil designs whilst retaining the convenience of a replaceable stylus and high output associated with moving magnet types. The cartridge employs a fixed samarium cobolt magnet and high output coil combination so that a very light iron/nickel cantilever end-piece can be used instead of the much heavier permanent magnet used in conventional designs. This reduces the moving mass allowing the stylus to trace the record groove more faithfully. Because of their high output, Goldring 2000 series cartridges should be used with the standard moving magnet phono input of an integrated amplifier.
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.
High-Pressure Aluminium Die-Cast Body
The 2400 features a high pressure, die-cast aluminium body shell which has been selected for its superior ability to quickly transmit unwanted resonances away from the generator and into the tonearm. A properly designed tonearm will dissipate energy transmitted into it by the cartridge body and effectively “ground” it due to its construction and quality bearing. However, it will not be able to do this, if the resonances remain in the cartridge body due to inefficient transmission. The 2500 body therefore has been designed to provide a fast secure path for resonant energy in order to quickly transfer it to the tonearm which is very often also made of the same aluminium material. This means that there is likely a good acoustic match across the boundary between the cartridge and the headshell. The new body also benefits from integrated M2.5 threaded mounting holes which means that it is very easy to mount onto the tonearm, negating the need for fiddly washers or nuts which need to be counter-held during adjustment.