DS Audio Grand Master Cartridge Tetsuaki Aoyagi

Tetsuaki Aoyagi

Over the last four years DS Audio's President, Tetsuaki Aoyagi, has been making a list – an Excel spreadsheet to be precise – detailing all the minor revisions that might add up to a major advantage in the evolution of the brand's 'optical' pick-up.


'To improve the S/N ratio we needed to obtain a higher output from the cartridge', says Tetsuaki, 'so we decided to use independent left and right LEDs and photocells. The position of these two LEDs could now be optimised to achieve a more substantial output from the cells'.

Tetsuaki also sought to reduce the mass of the moving parts while improving stiffness with a diamond cantilever. 'In addition, the size of the light-shielding plate was reduced, so the left and right sounds were less likely to mix and the separation of high frequencies would be greatly improved.

'Sound quality was significantly affected by the use of solid beryllium for the shading plate. This pure beryllium material is very expensive [and very difficult to work with], but switching away from aluminium made such a change to the sound that everyone could tell the difference – it was a surprise to me!'.

Tetsuaki's list extended to every material in the pick-up. 'This is not often mentioned, but by using stainless steel for the parts that hold the cantilever, the fulcrum is fully stabilised and the freshness of the sound is improved. But if the cartridge body is made entirely of stainless steel, the sound is too hard, so we used it only for internal support and alloy for the shell'. PM

Digital Stream Corporation
Kanagawa, Japan
Supplied by: Soundfowndations Ltd, Berks
0118 9814238