Audio-Technica AT33xMONO/II — True Mono moving coil cartridge

The AT33xMONO/II shares the "True Mono" principle with the /I: a moving coil that turns only the horizontal movement of the stylus into electricity, so the vertical axis — surface noise, dust, record warps — stays out of the signal. The difference is in the setup: output drops to 0.37 mV, tracking force rises to 2.5 grams and response is limited to 20 kHz, a more conservative package intended for older mono pressings and for arms that appreciate a little more load.

It keeps the 0.65 mil nude conical stylus, the duralumin cantilever and the die-cast zinc, aluminium and high-rigidity polymer body, with a neodymium magnet, permendur yoke, PCOCC coils and piano-wire suspension. The coil is 10 ohms with 27 µH and recommended load is 100 ohms or more; weight rises to 10.2 grams and vertical tracking angle stays at 20°. As with the /I, the stylus is not user-replaceable and the company offers a paid repair service.

The choice between /I and /II depends on the record and the arm: the /I gives more output and more top-end extension, and fits systems with modest phono gain; the /II, at 2.5 grams, feels more at home on medium-high mass arms and in the wide, shallow grooves of 1950s and 1960s pressings. Either way you want an MC phono stage with at least 60 dB of gain, and the amplifier's mono mode should stay off. This is a specialist listening cartridge: anyone playing mostly modern mono reissues will find a little more air in the /I.

Technical specifications:

• Type: moving coil (MC) "True Mono", 1/2 inch mount
• Stylus: nude conical, 0.65 mil
• Cantilever: duralumin pipe
• Frequency response: 20 Hz – 20,000 Hz
• Output voltage: 0.37 mV (1 kHz, 5 cm/s, horizontal signal)
• Tracking force: 2.3-2.7 g (2.5 g standard)
• Coil impedance: 10 ohms (1 kHz)
• DC resistance: 10 ohms
• Inductance: 27 µH (1 kHz)
• Recommended load: ≥ 100 ohms
• Output balance: 1.0 dB (1 kHz)
• Horizontal/vertical output ratio: 25 dB (1 kHz)
• Vertical tracking angle: 20°
• Static / dynamic compliance: 14 / 6 × 10⁻⁶ cm/dyne
• Dimensions: 16.1 × 16.6 × 26.1 mm
• Accessories: non-magnetic screwdriver, brush, 2 washers, M2.6 screws of 8, 10 and 13 mm, protector
• Weight: 10.2 g