Audio Note believes that the Moving-Coil cartridge is severely compromised by the usual active, high-gain, moving-coil preamplifiers. In order to remain quiet, moving-coil preamplifiers must use gain stages that are relatively insensitive to small-scale music signals and power supplies that are hard and electronic sounding. Stiff, highly regulated, low impedance, solid state power supplies are required to adequately quiet the high-gain, MC preamps. Preamps with these type of supplies sound 'overly tight and excessively regulated'. Impedance matching MC transformers have a special type of quietness that is musically consonant.
Did you ever hear live music that sounded stiff and tightly regulated? High gain voltage amplifier stages tend to sound jumpy and edgy. These same type of stages delete color and texture information. MC step-up transformers let music flow like a river - with grace and authority. MC transformers actually transfer so much more information that the high gain phono stage sounds empty by comparison.
MC transformer 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 Audio Note thinks music should be reproduced.
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 a 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'!
Historically, preamplifiers with high gain stages and large load resistors demonstrated a loss of information! Why then do so many manufacturers choose to use a high gain phono stage? Maybe it is cost. A transformer costs at least 100 times as much as a tube or transistor!!!!!! A really high-quality transformer (as only Audio Note makes) can cost 1000 times as much a high gain stage!
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 are very difficult to design quality transformers around. 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. Our 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. Audio Note 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. Audio Note uses more advanced forms of stamping, annealing, and finishing than any manufacturer in the world.
Audio Note makes Moving-Coil step-up transformers starting at less than $500, all the way up to $10,000.00. We recommend these transformers for all moving-coil based phono systems.
The Audio Note AN-S1 MC Transformer is the latest (copper) version of Kondo's first Audio Note design. It has been in production since 1976! Today it is manufactured in the UK and the quality is improved. It is supplied in both High and Low impedance versions. The Low impedance version is designed to work with the Audio Note Io2 Moving-Coil cartridge, but it is also highly recommended for use with other MCs that prefer low impedance loads. The High impedance version is perfect for all other MCs. Both high and low impedance versions have switches to further adjust the input impedance.
The Audio Note AN-S2 MC Transformer is the same as above, but achieves a sonic improvement by being housed in a solid copper chassis. The AN-S2 sounds smoother and more pure in the upper registers.
The AN-S3 is a silver wired version of the above transformers with a more premium core material. This transformer is the top of the UK manufactured MC transformer line. Sonically it is like adding a polarizing filter to a camera. Instrumental colors and textures are more clear and intensified. The "presence" aspect of reproduction is enhanced. This transformer showcases the big orchestra and enlivens a big band. It does not overload on big climaxes! This transformer is a true bargain for the veteran LP collector.
AN-S6c & AN-S7c
The Audio Note AN-S6c and AN-S7c Moving coil transformers are pure, state-of-the-art, expressions of what a MC step up can be. These are all-out Kondo designs that are manufactured in Audio Note's Tokyo factory. Exotic nickle cores and hand-drawn, age annealed, silver wire are used to create these transformers. Copper chassis and captive AN-Vx silver interconnect with pure, solid silver connectors are integral parts of these designs. Both transformers are highly adjustable. Input impedance, output load, and a choice of balanced or single-ended operation are among the available choices. These transformers are the perfect interface for all moving coil cartridges.
The AN-S7c transformer uses separate left and right channel transformers in mu-metal housings to dramatically increase channel separation.
Audio Note step-up transformers are a must with Audio Note Phono preamplifiers when the Audio Note Io2 or other low output moving-coil cartridges are used.
Audio Note has just introduced its first high-output moving magnet cartridges; the IQ-I and the IQ-II. These cartridges have a 6.5 mV output and can be readily interfaced with any phono preamp designed for use with high output MM cartridges. They have replaceable styli and are reasonably priced to compete with the most popular MMs.
The IQ-I uses a Gyger, type II diamond and the IQ-II uses the Gyger type I. Both cartridges weigh 6.3g. Their preferred load is 47K Ohms @ 150-200pF. They are designed to work with medium-mass tonearms, such as the Rega or the Audio Note.
The Audio Note Io ("eye-oh") Cartridges
Long time followers of the high-end know the Audio Note Io cartridge as the ultimate MC cartridge. Introduced in 1982, this cartridge has yet to be improved upon.
The revolutionary nature of the Io design runs contrary to most commonly held criteria, but results in moving coil cartridges which are second to none in terms of dynamic response, balanced energy distribution across the entire frequency range, separation, timbral reproduction and ability to suppress vinyl surface noise.
The Io-2 MC Cartridge
Magnetic transformer materials impose their own grain structure on the reproduced signal. For more than three decades, Alnico has been cherished as the most "grain free" and dynamically natural of all the available materials. Only electro-magnets, like the ones used in the Io-Ltd. are more grain free.
In order to develop a super powerful magnetic circuit, Mr. Kondo combined two very expensive Alnico (Aluminum-Nickel-Copper) magnets with a very pure iron yoke. This iron yoke is precision machined and gold plated to prevent corrosion. This design ensures an accurately focused field of over 2,500 Gauss, by far the most powerful of any cartridge. This extraordinary magnetic field permits a radical reduction in the number of turns on the coils, with the twin benefits of reducing distortion and improving sensitivity.
To compliment this engineering, a special core was developed from ultra thin amorphic material to ensure increased output without the problems of saturation, common in other MC cartridges. The coil arrangement is shielded with a very thin copper layer to exclude extraneous noise and vibration, and to provide the purest possible output.
With less than .1mv output and weighing over 18g this moving-coil type transducer requires a medium to high mass tonearm and an Audio Note Silver wound step up transformer (i.e.: AN-S6c & AN-S7c) to achieve the best sound quality. The Io-2 cartridge weighs 18g because alnico magnets are heavy! In this case, mass was traded for a more refined and grainless sound than either samarium cobalt or neodymium. The Io-2 is encased in a pair of brass panels, which are bolted around the magnet assembly. This forms a very rigid block with no internal cavities save that around the coils. Holes are provided for six (!!!) mounting screws to further enhance rigidity.
The Io-2 cantilever is also highly original in design. It is vitally important for the cantilever and stylus assembly to be as light and rigid as possible. No motion must be lost or gained while the stylus tracks the vinyl groove and no energy should be stored and released. The optimum cantilever was found to be a thick-walled, tapered titanium tube. This cantilever tube is tapered in diameter (from small to large) over its length and the wall thickness changes from thin at the stylus to thick at the yoke. This shape and cross-section allows for the most efficient energy transfer and dissipation. No other MC cartridge uses this important design innovation. This innovation is one of the big reasons that the Io-2 sounds so clear and true.
To achieve the correct mechanical damping of the stylus/motor assembly, Mr. Kondo settled on a ultra-precision butyl rubber damper, which offers unaffected performance under a wide range of temperature and humidity conditions. The tension on this damper is adjustable, permitting accurate set-up of each cartridge's individual suspension.
The stylus assembly is completed with a highly polished diamond van den Hul-1 stylus which, compared to its competition, demonstrates better tracking of high frequencies, lower record wear, and much lower transmission of record noise.
Originally made in Japan at the Audio Note factory, the Io-2 has been manufactured in the UK since 1991. The latest example (made in the UK) is referred to as the Io-2v. The Io cartridges work best on medium to high mass tone arms.
Io-1 MC cartridge
This cartridge is the same as the Io-2v except for the material of the cartridge body. The Io-1 has a much lighter body. This version weighs in at a mere 11g and is therefore more compatible with a broader range of popular audiophile tonearms. Sonically, it has a bit less weight and presence than the Io-2. In balance, it has a little more magic, a little more elegance and some extra 'draw you in' ability compared to the Io-2. The IoII has a strong, 'matter-of-fact' feel while the Io-1 is subjectively more transparent and open feeling. The Io-2v is closer to the grainless reality of the master tape and the Io-1 might be said to be a little more "well-dressed" and seductive.
I recommend the Io-1 for non-Kondo based systems and the Io2v and Io-Ltd.. in all-out Kondo systems.
In 'Audiophile' (June 1993) Malcolm Steward stated that; "The profusion of detail that the Io brought from this recording wasn't clinically detached from the music but was woven cogently into the performance...It gave meticulous insight...without losing sight of the music's flow."
Jason Kennedy writes for Hi-Fi Choice, Nov., 1991:
"One felt that the limitations of the medium were close at hand...it even managed to improve on one of Ortofon's forte's; the high frequencies. This aspect enabled the cartridge to produce superbly defined acoustic spaces with incredible width and depth."
This is it! The outer limits of Lp playback. This cartridge substitutes a electro-dynamic (field coil) magnet for the Io's normal Alnico magnet.
Remember when you were a child and you made a magnet by wrapping a wire around a nail and attaching it to a battery? This is the same principle but the Io-Ltd. has its own, 800ma. DC power supply. The cartridge and tonearm actually get warm!
The Io-Ltd. requires two extra wires installed in the tone arm. Audio Note sells a special tone arm for this cartridge. We can also rewire most tonearms for use with this product. For further details please call Audio Note USA direct.
The Io-Ltd. cartridge gives the best Lp reproduction EVER! The electro-dynamic magnet makes the reproduction nearly as grainless as master tape! Once you hear this cartridge play records, all other cartridges sound rough and grainy.
Updated :06 Aug 1998
This page was updated on: 06 Aug 1998
This page is the property of Audiophile.com.sg ę 1998