Audio Note IO II Moving Coil Cartridge

Generator Principle

The moving coil principle was chosen as the basis for the design of the IO range of cartridges, as it offers greater linearity in terms of electrical output from the mechanical movements of the stylus than any other system. We investigated moving iron, moving magnet, strain gauge, electret and electrostatic generators, and even took the unusual step of acquiring a Toshiba cartridge that employed light emitting diodes to generate the signal from the groove, but in the end it was felt that the quality of the moving coil system as described by P. G. A. H. Voigt would yield the best overall results.

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Mechanical Construction

To ensure that the stored information on the disc is precisely recovered, it is essential that the mechanical movement of the stylus is accurately translated into an electrical signal. Any extraneous excitation arising as a result of vibrations in the cartridge housing must be eliminated.

Therefore, in the design of the Audio Note (UK) cartridges, considerable attention has been paid to the rigidity and structural integrity of the body, and to ensuring that the adopted mechanical construction stores the absolute minimum of resonant energy, which will degrade the signal derived from the disc being played.

Mechanical integrity of the cartridge body is an aspect of design that has never been adequately dealt with before, and as a result all other cartridges suffer greatly from colourations derived from internal resonances and/or energy stored in their body assemblies.

To achieve the incredible level of mechanical integrity required for the IO cartridges, all aspects of body design were reexamined, to minimise standing waves and eliminate any resonating air pockets within the assembly.

The benefits of getting the mechanical assembly right would be lost if the complete assembly could not be rigidly mounted in the tonearm, hence the incorporation of the largest possible surface mounting area and the provision of up to six (6!) bolts to secure the cartridge to the head shell.