Ortofon 2M Mono Premounted Cartridge

Is the Ortofon 2M Mono Premounted Cartridge the Right Choice for Your Mono Records?

Ortofon 2M Mono Premounted Cartridge is a mono phono cartridge designed for playing mono microgroove LP vinyl records. This premounted mono cartridge is built for collectors who want true mono reproduction from their mono pressings using the stereo system they already own. It arrives mounted on Ortofon’s SH-4 headshell for S-shaped tonearms. Its key differences are a strapped output, a nude spherical stylus and the ready-mounted headshell format.

How does the Ortofon 2M Mono Premounted Cartridge play true mono on a stereo system?

The Ortofon 2M Mono Premounted Cartridge is wired with a strapped output, which delivers the same output signal from both sets of pole pins. Because both channels carry that identical signal, you don’t need mono-specific equipment downstream. Your existing stereo turntable, phono stage, amplifier and speakers can reproduce true mono. That makes the cartridge a direct route into mono playback without rebuilding your system around it.

Why does this mono cartridge use a nude spherical stylus?

This mono cartridge is fitted with a nude spherical diamond with an 18 µm tip radius, which Ortofon describes as an optimal solution for mono microgroove LPs. The diamond is the only part of a cartridge that touches the record groove, so its shape governs how accurately the cartridge reads the groove. Spherical diamonds are sometimes called conical diamonds.

The cartridge’s nude construction matters as much as its shape. A tipped, or bonded, diamond has its tip mounted on a metal shank. A nude diamond weighs less than a tipped one, and Ortofon links that lower weight to quicker responsiveness, greater detail and reduced distortion. Ortofon uses nude diamonds in its most advanced hi-fi cartridges.

Will the Ortofon 2M Mono Premounted Cartridge fit your turntable?

The Ortofon 2M Mono Premounted Cartridge is designed for direct, easy mounting and replacement on S-shaped tonearms, using its SH-4 headshell. Check your turntable’s manual or manufacturer specifications before you order. Ortofon advises that turntables can have specific requirements for cartridge type, mounting style and tonearm compatibility.

The cartridge’s SH-4 headshell is strong and rigid, with a slim, lightweight design. Its long finger lift gives you an easy grip when you lower the stylus onto a record or lift it away.

Does your tonearm’s effective mass suit this cartridge?

This cartridge is a moderate-compliance design. Its dynamic lateral compliance of 18 µm/mN sits inside Ortofon’s moderate band of 10 to 20 µm/mN. Compliance and total tonearm system mass together set the cartridge’s resonance frequency. Ortofon treats 7 to 12 Hz as the optimal range and recommends 10 Hz.

The cartridge’s resonance frequency can be calculated with Ortofon’s formula: F = 1000 ÷ (2π × √(M × C)). Here M is the total tonearm system mass: the cartridge, the headshell and screws, and the tonearm’s effective mass, all in grams. C is the lateral compliance. The cartridge weighs 7.2 g on its own and 16.7 g premounted. Taking 16.7 g as the cartridge-and-headshell figure, a tonearm with an effective mass of 8 g gives a resonance of about 7.6 Hz. A 12 g arm gives about 7.0 Hz.

This cartridge reaches a resonance of 6.5 to 7 Hz on tonearms with an effective mass between roughly 12 g and 16.5 g. Ortofon treats that band as an acceptable option that might be used without problems. Its resonance falls below 6.5 Hz on heavier tonearms, a result Ortofon describes as questionable because the system might not work properly. Calculate the figure for your own tonearm before you buy.

What phono stage settings does it need?

The premounted cartridge is specified for a recommended load resistance of 47 kOhm and a recommended load capacitance of 150 to 300 pF. Its output voltage is 4 mV at 1 kHz (5 cm/sec). Confirm that your phono stage’s input offers this loading before you order.

What setup does it need?

The Ortofon 2M Mono Premounted Cartridge is set up around a recommended tracking force of 1.8 g, within a working range of 1.6 to 2.0 g. Ortofon specifies a 20° tracking angle. The ready-mounted SH-4 headshell makes setup on your turntable easy. Ortofon provides a downloadable user guide covering setup.

Should you buy the Ortofon 2M Mono Premounted Cartridge or another 2M model?

The Ortofon 2M Mono Premounted Cartridge is the choice if mono microgroove LPs are what you want to play, your turntable has an S-shaped tonearm, and you want true mono without adding mono-specific equipment. Ortofon’s cartridge finder lists other 2M models, including the 2M Red, 2M Blue, 2M Bronze, 2M Black and 2M Black LVB 250. Use the finder to compare them if your collection calls for a different cartridge.

The 2M Mono SE is a related Ortofon model. According to Leif Johannsen, Ortofon’s Chief Officer of Acoustics and Research, the company created it as a tribute to The Beatles’ mono box set released in 2014. Ortofon offers the 2M Mono in more than one variant, so select the version that matches your tonearm when you order.