Cartridges — Audio-Technica AT33xMONO/II

The AT33xMONO/II is the lower-priced of the two mono cartridges in Audio-Technica's AT33x series, launched on 27 October 2025 at USD 449 and, like its siblings, handmade in Japan. It is built for microgroove vinyl and uses two horizontal PCOCC coils placed at the fulcrum of the cantilever, so only lateral groove motion produces output. Audio-Technica states that this also makes it safe to play stereo records, and it points to 1950s and 1960s mono jazz pressings as the target material.

Key specs that matter

A 0.65 mil conical diamond is mounted on a duralumin pipe cantilever. Output reaches 0.37 mV at 1 kHz and 5 cm/sec, balance between the two outputs is 1 dB, and horizontal output exceeds vertical by 25 dB. Frequency response is quoted as 20 Hz to 20 kHz. Impedance and DC resistance of the coils are each 10 ohm, and inductance is 27 microhenry at 1 kHz. Static compliance comes to 14 x 10-6 cm/dyne and dynamic compliance at 100 Hz to 6 x 10-6 cm/dyne. It tracks at 2.3 to 2.7 g, with 2.5 g recommended, and the vertical tracking angle is 20 degrees. The cartridge uses standard half-inch mounting and measures 16.5 x 16.0 x 26.4 mm.

Engineering and use context

This is where the MONO/II departs from its sibling - a samarium cobalt magnet works with a pure iron yoke in the magnetic circuit, again shaped for monaural reproduction. The high-hardness duralumin cantilever tapers toward the conical tip to improve response. Audio-Technica calls the coil layout True Mono and credits it with lower surface noise on playback. Its body is a composite in which a base of rigid, dense zinc die-casting is joined by aluminium and a high-rigidity polymer, the zinc serving to keep vibration in check. As part of the same overhaul, which Audio-Technica describes as the first extensive one in years, the suspension mechanism was revised. The PCOCC copper used for the coils is a continuously cast conductor chosen for signal transmission.

Pairing

A head amplifier or MC phono input is required, and the recommended load is more than 100 ohm. Anyone running a stereo turntable can fit it in place of a stereo cartridge for mono sessions, provided the tonearm can apply the higher tracking force this model needs. A non-magnetic screwdriver, washers, M2.6 mounting screws, a cartridge protector and a brush are packed with it.

Alternatives

The AT33xMONO/I uses a neodymium magnet with a permendur yoke, extends to 30,000 Hz and tracks at 2.2 g.