Ortofon 2M 78 Replacement Stylus

Ortofon Stylus 2M 78: The Replacement Stylus for 2M Mono and 2M 78 Cartridges

Ortofon Stylus 2M 78 is a replacement stylus for the Ortofon 2M Mono and 2M 78 cartridges. It’s for owners of either cartridge who need a new stylus, or who want a 78 rpm option for an existing 2M Mono. Two things set it apart from the rest of the 2M stylus range: its R 65 µm spherical diamond, and a closed interchangeability group that holds only two cartridge bodies.

Which cartridges does the Ortofon Stylus 2M 78 fit?

Ortofon Stylus 2M 78 is interchangeable only with the 2M Mono and 2M 78 bodies. Ortofon divides its 2M styli into three groups, and each stylus fits only the bodies in its own group:

1. 2M Red, 2M Blue and 2M Silver
2. 2M Bronze, 2M Black and 2M Black LVB 250
3. 2M Mono and 2M 78

A 2M 78 owner gets a like-for-like replacement. A 2M Mono owner gets a second stylus for the same body. Owners of any other 2M cartridge can’t use it.

Will this stylus suit your tonearm?

Stylus 2M 78 is rated at 18 µm/mN dynamic lateral compliance, which Ortofon classes as moderate. Compliance and the total tonearm system mass together set the system’s resonance frequency. Ortofon calculates it with this formula:

F = 1000 ÷ (2 × π × √(M × C))

M is the total mass in grams: the cartridge, the headshell and screws, and the arm’s effective mass. Ortofon rates 7 to 12 Hz as optimal and recommends 10 Hz. At 18 µm/mN, the formula gives these results:

• A total mass of about 10 g gives around 12 Hz.
• About 14 g gives the recommended 10 Hz.
• About 20 g gives around 8.4 Hz.
• About 29 g gives around 7 Hz.

Ortofon says 6.5 to 7 Hz and 12 to 14 Hz may work without problems. It treats anything outside that as questionable. It names moderate-mass tonearms, those with 11 to 25 g effective mass, as good companions for moderate to low compliance. Its examples include the SME IV, SME V, Triplanar and Graham arms. To check your own arm, add its effective mass to your cartridge body and headshell weights, then run the formula.

How do you set up the Stylus 2M 78?

Stylus 2M 78 is specified for a tracking force of 1.6 to 2.0 g (16 to 20 mN), and Ortofon recommends 1.8 g (18 mN). Set your counterweight to 1.8 g and keep any adjustment inside the published range. The stylus has a 20° tracking angle, which is the vertical angle Ortofon specifies relative to the record. If your tonearm has height adjustment, that’s the control that changes it. Ortofon publishes a downloadable user guide for fitting the stylus.

What does its spherical diamond do in the groove?

Stylus 2M 78 is a spherical type, which Ortofon also calls conical, with an R 65 µm tip radius. The diamond is the only part of a cartridge that touches the record, so its shape governs how the groove’s modulation reaches the cartridge. A spherical tip presents a rounded profile to both groove walls, and its radius determines how it seats in the groove. Ortofon gives this 65 µm profile to the stylus it names for 78 rpm records.

What do its tracking and response ratings tell you?

Stylus 2M 78 is rated to track 70 µm of groove modulation at 315 Hz. That’s the amplitude it can follow at that test frequency while keeping contact with the groove walls. Its frequency response is 20 Hz to 20 kHz within +3/−1 dB, which shows how far its output departs from flat across the audio band.

What does a replaceable stylus mean for ownership?

Ortofon Stylus 2M 78 is a separate, user-replaceable part. When the diamond wears, you buy a stylus rather than a complete cartridge. Ortofon’s guidance links replaceable styli with Moving Magnet cartridges and points to easier upgrades as their advantage. A 2M Mono body accepts either its own stylus or this one, so a single mounted cartridge covers two stylus choices.

Should you buy the Ortofon Stylus 2M 78 or a complete 2M 78 cartridge?

Stylus 2M 78 is the right purchase if you already own a 2M Mono or 2M 78 body. Without one, the complete 2M 78 cartridge is how you get this stylus. The stepped upgrades in other parts of the 2M range don’t reach this group. In the Red, Blue and Silver group, the 2M Silver cartridge improves on the 2M Red with a special suspension and silver-plated copper wire. The 2M Blue improves on both with a Nude Elliptical diamond. Those upgrades depend on shared bodies, so a 2M Mono or 2M 78 owner can’t move into them by changing the stylus.