Головки звукоснимателя — Audio-Technica AT-OC9XSL

The Audio-Technica AT-OC9XSL is the top model of the OC9X dual moving coil line, using a nude Special Line Contact stylus on a solid boron cantilever. It fits a standard half-inch headshell mount. The aluminium body is pre-threaded, which removes the need for nuts when fixing it to a headshell.

Key specs that matter

Output voltage is 0.4 mV at 1 kHz and 5 cm/sec, and frequency response runs from 20 Hz to 50,000 Hz. Channel separation is 28 dB and channel balance is 0.5 dB, both at 1 kHz. Coil impedance and DC resistance are each 12 ohm, and coil inductance is 25 mH at 1 kHz. Recommended load impedance is 100 ohm or more. Static compliance is 22 x 10-6 cm/dyne and dynamic compliance is 18 x 10-6 cm/dyne at 100 Hz. The vertical tracking force range is 1.8 to 2.2 g, with 2.0 g as the standard setting. The cartridge weighs 7.6 g and measures 17.3 mm high, 16.8 mm wide and 25.7 mm deep.

Engineering and use context

The stylus tip has a curvature radius of 38 x 7 µm and is mounted on a nude rectangular shank. The cantilever itself is a 0.28 mm diameter rod of solid boron. Coil wire is PCOCC, the copper made by the Ohno Continuous Casting process, and the pair of coils forms an inverted V, producing each channel on its own coil and lowering the pressure on the stylus. The OC9 line dates back to 1987, and the OC9X generation, the fourth, was shown at HIGH END Munich in May 2019 and went on sale in July 2019 at USD 729. Within the series, the Special Line Contact, microlinear and Shibata versions have boron cantilevers, while the elliptical versions use aluminium. The aluminium body was chosen to reduce resonance. These three boron models also share a magnetic circuit of neodymium magnet and permendur yoke, whereas the elliptical models pair neodymium with a pure iron yoke. The series offers five stylus choices - Special Line Contact (XSL), Shibata (XSH), microlinear (XML), nude elliptical (XEN) and bonded elliptical (XEB). The box includes a non-magnetic screwdriver, two washers, installation screws in several sizes, a plastic stylus protector and a brush.

Pairing

Any MC phono preamplifier with a load at or above the recommended value matches the electrical requirements. A step-up transformer placed before a moving magnet input is the other way to reach the gain this low-output cartridge requires.

Alternatives

The Audio-Technica AT33Sa is another MC cartridge of the brand, the first to carry a Shibata tip, mounted on a tapered boron cantilever.