The Ortofon 2MR 78 sits within the 2MR series, which adapts the engine and stylus assemblies of the popular 2M moving magnet range to a narrow, low-profile housing intended for Rega-style tonearms. The 2MR 78 is the dedicated 78 RPM variant, engineered for the wider groove geometry of shellac pressings rather than the modern microgroove vinyl handled by the rest of the range.
R-Mount Housing
The 2MR housing has been specifically designed for turntables and tonearms with low-form-factor cartridge requirements, such as those produced by Rega. Its narrow body integrates without modifications or spacers beneath the tonearm, allowing fitment using just two screws. This makes installation noticeably simpler on Rega and similar arms compared to a standard half-inch mount.
Mono Engine and Spherical Stylus
The 2MR 78 carries forward the mono-tuned engine and 65 µm spherical diamond tip used elsewhere in the 78 RPM cartridge family. The spherical profile sits correctly in the wider grooves of shellac records, where the elliptical or fine-line tips fitted to standard 2M models would ride too low. Output voltage is 4 mV at 1 kHz, 5 cm/sec, suitable for any standard MM phono input.
Tracking and Compatibility
Ortofon recommend a tracking force of 1.8 g, within a permissible range of 1.6 to 2.0 g. Dynamic lateral compliance is rated at 18 µm/mN, suiting the medium-mass tonearms typical of Rega and comparable decks. The cartridge presents a 47 kΩ load impedance and 150 to 300 pF capacitance to the phono stage, in line with the standard 2M series.
Also Available
Those using a standard half-inch tonearm rather than a Rega-style arm should consider the Ortofon 2M 78, which shares the same engine and stylus but uses a conventional half-inch mount.
