Optical Cartridge from DS Audio
Japanese firm DS Audio has eliminated magnets in its high end phono cartridge. Instead it uses an optical pickup. But that optical pickup may not work quite the way you expect.
There are no lasers firing down into the vinyl grooves. Such systems, while tried in the past, require feedback loops and servo motors to keep the cartridge properly positioned. DS Audio's system uses a conventional stylus and cantilever but gets rid of the magnet and coil.
Why? Because of Lenz's law. A conventional phono cartridge generates an electrical current by means of a magnet and a coil moving with respect to each other. This is amplified and equalised to drive a high fidelity audio system.
But that current itself creates a magnetic field which opposes the original one, reducing the accuracy of accuracy of movement in the system. DS Audio calls this an 'electromagnetic friction force'.
Instead the DS Audio DS-W1 optical cartidge uses a conventional stylus, but with an optical system tracking the movement of the stylus cantilever rather than having a magnet or coil mounted on its end. This pickup works in proportion to the position of the cantilever (and thus the stylus) rather than its velocity, eliminating one stage of EQ.
This unique cartridge comes with its own system to provide power, RIAA EQ and pre-amplification, but is installed on the user's preferred tone arm.
Extremely well received in the audiophile press, the DS Audio optical cartridge system is now available in Australia for $7,500 from Absolute Hi End.
Stephen Dawson started writing full time about home entertainment technology just weeks before the DVD was launched in Australia. Since then he has written several thousand product reviews amounting to millions of words for newspapers and magazines around Australia.