Here is a nice interview with Dr Tominari of Dynavector Systems, who designed the first gemstone cantilever cartridge and later designed fabulous XV-1 and DRT XV-1. In this interview you will find more about Te-Kaitora cartridges, Karat Nova series and many more amazing products of that era.
here is a bit from the interview:
here is a bit from the interview:
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. Tominari: 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. Tominari: 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 licence fees. (Laughs)