hifi plus magazine
Isuue 8 November / December 2000

Unsung Hero

Dr Tominari of Dynavector Systems

Interviewed by Roy Gregory

DV507 with Nova13D For most people Japanese hi-fi is limited to midi systems and massive corporations, whereas in fact Japan has a vibrant and inventive high-end market which we in the West know little or nothing about. But whether we are aware of it or not, it's a market which has had profound effects on our own. The single-ended amplifier / high efficiency speaker movement started many years ago in Japan, reaching us through the likes of Be Yamamura in Italy and Jean Hiraga in France.

Likewise, there have always been exclusive Japanese high-end products which have enjoyed near legendary status amongst the gai-jin. Koetsu and Audio Note are the two that spring to mind, and it's no coincidence that Sugano-san and Kondo-san are about the only Japanese high-end designers that most of us know by name.

However, there is another, tiny, specialist company which has a track record of consistent innovation and excellence. It too has enjoyed a long and successful association with Western audiophile markets. It too has kept the faith with what many see as redundant technology. And typically, it's done it at lower price levels than the other companies I've mentioned. That company is Dynavector, and its guiding light is Doctor Noboru Tominari.


RG. How long have you been making pick-up cartridges, and why do you continue when so many others have stopped?

Dr T. More than 23 years now. It started as a hobby when I retired from the University. I was always fascinated by cartridges as I feel they have a huge influence over the reproduction of recorded sound. Ten years ago surround sound appeared and although it impressed many people, especially for movie sound, it made no impression on me when it came to reproducing music. On the other hand, many people in Japan have huge collections of CDs and vinyl records at home.

Many people listen to music at home but when you come back from the concert you find that the sound is not good - not realistic. I was really worried about this, and the way that the major Japanese companies were ignoring high quality music reproduction for most people. Despite the existence of large stereo music collections they were pouring all their resources into the development of surround sound media. Now music will have to be re-recorded for the new formats, losing the wonderful performances that we already have, making music a poor relation to the technology.

Most audiophiles already have several sources and software to go with them. They don't want to start again with yet another new format, so the marketing effort behind DVD has gone into the home cinema market, concentrating on selling people the extra equipment they need for this, and films rather than music. That is why listening to music is a declining hobby. People buy the new equipment but their old recordings don't sound good on it, and they can't afford to replace them with new ones. I became convinced that what was required was a system to get better sound from their existing music collections.

So this is why I continue to make better cartridges and also developed Super Stereo (a fascinating variation on surround sound which we will be returning to shortly). For high end listeners who already have good amplifiers and speakers, there is a whole legacy of great performances, great conductors, pianists or singers, stretching back nearly one hundred years and just waiting to be enjoyed.

We should apply the best technology to their reproduction, but it should be analogue technology because these are analogue recordings. They were recorded in mono or stereo, so why try to replay them with a multi-channel digital system?Karat 17D2

But to get the best from these records you need a very high quality cartridge. Working with prototypes of my latest design I was astonished how good these old records could sound. Much better than a modern CD.
Unfortunately, this new cartridge is not as simple as something like an Ortofon. Most high quality cartridges are based on extremely simple structures developed fifty years ago, and very old fashioned in their use of magnet materials. Instead I use eight Alnico magnets to create a much more uniform magnetic field. The results of experiments were so impressive to me. that I immediately incorporated this technique into a new cartridge, the XV-1. One dealer in Japan, as soon as he heard this cartridge immediately said it sounds superior to any DVD or CD. This cartridge reproduces the air atmosphere of a recording, even from a very old record, which is absent from digital sources.

RG. The first Dynavector product I became aware of was the original Karat cartridge, with its solid ruby cantilever. Were you the first person to employ gemstone cantilevers?

DR T. Absolutely. I get my gemstone cantilevers from Namiki, and the first time I asked them about constructing one they couldn't understand what I wanted such a large stylus for! But I was convinced that you should use as short and stiff a cantilever as possible.
This was quite widely recognised but no one believed that the technology existed to create such a short gemstone cantilever. They thought it was impossible but I dared to try it. It was a very unusual solution at that time.

In order to achieve it we had to develop a parallel technique that enabled us to wind incredibly fine wire for the coil. Our wires are only 11 microns in diameter. Every other cartridge uses at least 20 microns.

RG. Why do the fine wires help you use in using a short cantilever?

Dr T. At the end of the cantilever is the armature. On the very short gemstone cantilevers there is no space, so the armature must be much smaller than normal. Unless we use the fine wire for the coils there will be insufficient windings for a working output level. We did this twenty years ago, and are still the only company who can use such fine wire. Eric Rohmann, who was president of Ortofon until some years ago, even tried to buy one of our machines. Incidentally, you are aware that Ortofon and Grado hold all the patents on moving-coil cartridge designs. Dynavector was the only Japanese company that ever paid the license fees. (Laughs)

RG. The first Karat cartridge hada 2.5mm cantilever, but over theyears that has shrunk down to 1.7mm.

Dr T. At first when I tried short cantilevers I worked in sapphire or ruby and their resonance dictates alength of 2.5mm. But in Diamond, it is possible to use 1.7mm. We even made a very special product for the US high end market with a cantilever only 1.3mm long, and called the Karat 13D. It was our flagship model and sold nearly 60 pieces in America.
The 17D was the first diamond cantilevered cartridge that we made, and the 13D was a very special development of it, using a special body and headshell arrangement.

RG. The next major development that you produced was the Flux Dumper, which first appeared on the XX1. What does it do?

Dr T. It first appeared on the XX1, but now it is incorporated into all our cartridges. It involves winding a wire around the front yoke of the cartridge. Experiments showed that movement of the coils was generating a voltage in the yoke which in turn effects the linearity of the magnetic flux.

It is this that makes many poor moving-coil designs sound thin and irritating.
By short circuiting the yoke we prevent this happening, which leads to a much smoother and more natural high frequency balance. The effect is quite noticeable, which is why we put a switch on the XX1, so that people could hear the effect.

RG. What is the relationship between the Te-Kaitora andt he XXl?

Dr T. The Te-Kaitora is really just a special version of the XX1 made for Mr Denson who distributes Dynavector products in Japan and also builds the Dynavector electronics. It has no body, and uses better magnets and selected parts. And also better quality wires as well.

RG. I notice that neither the XX1, the Te-Kaitora nor the XV-1 use gemstone cantilevers. Why is that?

Dr T. At the moment, the construction of this magnetic assembly used in these cartridges requires a long cantilever. It would be very difficult to engineer this for a short cantilever, and also very, very expensive.

RG. I also notice that the output on the XV 1 is slightly higher than previous models.

Dr T. Yes. That is to make it easier to use with conventional phono electronics. We have also created a moving-coil head amp to go with our cartridges, and those from other manufacturers. It is an updated version of a circuit that I first used 20 years ago, but it is improved with modern components from the United States and Japan. The quality of the parts used has a huge influence on the sound quality of phono electronics.

20 years ago I started with the idea of basing the amplification of low output moving-coil cartridges on current rather than voltage. Theoretically current amplification is far better than existing hi-fi head amplifiers, which are based on voltage amplification.

Unfortunately, 20 years ago the components available were not as advanced or capable of low noise performance. The development of analogue IC chips has really improved things, especially in terms of signal to noise ratio. So last year I built a new version of the circuit and was amazed by the improvement in performance.
The current version uses only the very best components that I can find.

RG. And the unit amplifies from low output moving oil up to moving magnet level?

Dr T. That is correct. You must connect it to an existing moving magnet stage, along with its associated equalisation. Currently of course, many audiophiles are using line stage pre-amplifiers with no equalisation built in, so I am working on an equalisation circuit which once incorporated into the unit will mean that I can then increase the gain all the way to line level.


Using the PHA-100 the sound of all moving coils is fuller and more natural.
Because it presents the cartridge generator with a dead short it maxi-mises the output current, which in turn leads to a smoother sound with more body. It also works better with very low output cartridges for this reason.

As mentioned, Dr Tominari has be a source of constant innovation. His use of gemstone cantilevers and the development of the Flux Damper, PHA-100 head amp and the new magnetic structure for the XVI are only part of the story. We will be reviewing one of his SuperStereo units in the next issue, but by way of an introduction here are two reviews, one of his latest cartridge, the XVI , the other of his long running and eclectic tonearm, the DV 507, along with the ultra rare DV 13D cartridge. You only have to look at these products to appreciate that Dr Tominari is not one to simply accept the status quo. As you will see, it's an attitude that has led him to develop some fascinating and technologically challenging products.

All the images and text are permission by hi-fi+ Publishing Ltd

 


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