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If the core material sounds so much differently, then the material of coil would make the sound different, a simple logic. And I tried silver as a coil of transformer, first in the world. The sound with this transformer was just fabulous, far different from the former product, resulting in the sound so clean and so pure, arousing the addiction to listen. As the core material, I have asked one of the manufacturers to use sharp sound material. Some may say it is the world of maniac, but there are things that cannot be explained in the field of electricity. The reason is because sound is the world of mechanical vibrations. – Hiroyasu Kondo, Audio Note Co., Ltd., Tokyo – Dec., 1998 Kondo
MC transformers reveal a breathy air that charges the room – this is due to a larger quantity of small-scale information. In contrast, high gain phono stages tend to sound gray and tight…not the way Kondo thinks music should be reproduced not the way in which Audio Note products are made to sound.
The MC cartridge is essentially a low voltage/current generating device and the inductive-reactive, low DCR, MC transformer is the perfect load. The proportions of the music’s energy are much better preserved when a high-quality transformer is the load that the cartridge “sees”.
The transformer load is the gentle bridge that allows the most complete signal energy transfer. Another reason this “gentle bridge” is so effective at reproducing small scale information is that a properly designed transformer provides an impedance match that minimizes reflections from the load side of the cartridge/gain interface.
Voltage loss of a transformer is fundamentally ‘zero’! One of the most important aspects of MC transformer design is the selection of core materials. High permeability (i.e.: Superpermalloy/T-10) core materials are expensive and hard to make. Due to their extreme permeability, these exotic core materials make it very difficult to design quality transformers.
The designer must carefully balance wide bandwidth with a wide permeability ratio area. The shape or ‘aspect ratio’ of the core must be experimentally derived and the final results must be proven in listening tests under actual music conditions. Tests have shown that ‘E/I and L’ type cores generate local magnetic saturation due to their mechanical structure with joints.
The resonance or ‘beat’ of a core material must also be considered. Kondo has done much research on the resonant character of core materials and construction. When forming cores, permeability decreases by 50-60% if hard press stamping is used.
To regain permeability, hydrogen annealing must be used. Kondo uses more advanced forms of stamping, annealing, and finishing than any manufacturer in the world.