Головки звукоснимателя — Audio-Technica AT33Sa

The Audio-Technica AT33Sa is a moving coil cartridge with two coils and the first Audio-Technica MC model to use a Shibata line contact stylus. The stylus sits on a tapered solid boron cantilever with a double damper, and the whole assembly weighs 6.9 g. Its coils have an impedance of 10 ohm, and the recommended load is at least 100 ohm when a head amplifier is connected.

Key specs that matter

Output voltage is 0.4 mV at 1 kHz and 5 cm/sec. Frequency range extends from 15 Hz to 50,000 Hz. Channel separation is 30 dB and channel balance is 0.5 dB at 1 kHz. DC resistance is also 10 ohm. Static compliance is 40 x 10-6 cm/dyne, while dynamic compliance at 100 Hz is 10 x 10-6 cm/dyne. The vertical tracking angle is 23 degrees. Vertical tracking force spans 1.8 to 2.2 g, and 2.0 g is the standard value.

Engineering and use context

The AT33 name traces back through the AT33E of the early 1980s to the AT34 of 1977, the first dual moving coil design from Audio-Technica. The Shibata tip is mounted on a nude square shank. Tapering the boron cantilever reduces its weight toward the tip, which Audio-Technica links to better high frequency response. The double damper controls cantilever movement. The housing is a precision cast hard aluminium alloy, sandwiched top and bottom by hard synthetic resin to suppress parasitic resonance. Both coils use copper wire from the Ohno Continuous Casting process (PCOCC) and sit in a reverse V layout that gives each channel its own coil for power generation. The coils are fixed inside a strong but light VC mould that limits unwanted vibration. The magnetic circuit pairs a neodymium magnet, with a maximum energy product of 50 kJ/m3, with a permendur yoke chosen for its high saturation flux density. The brick-shaped body has a gold finish and uses standard half-inch mounting with non-threaded holes. Its US price is USD 949.

Pairing

The 0.4 mV output calls for an amplification stage built for MC cartridges, so the signal goes to a dedicated moving coil phono section, or through a step-up transformer that lifts it for an MM input stage. Audio-Technica offers the lightweight MG10 headshell with threaded inserts, which accepts the half-inch mount.

Alternatives

The Audio-Technica AT-OC9XSL, top model of the OC9X series, is an MC alternative with a Special Line Contact stylus on a 0.28 mm solid boron cantilever, 12 ohm coils and a threaded aluminium body.