Mobile Fidelity - MasterTracker MM Phono Cartridge

The top of MoFi’s moving-magnet line: a V-Twin dual-magnet generator with a Micro-Linear diamond stylus on a tapered aluminum cantilever, Ohno continuous cast copper coils, and a well-damped billet aluminum body.

MoFi cartridges are designed by looking at where a record starts: on a cutting lathe like the model used at Mobile Fidelity Sound Lab. The MasterTracker’s V-Twin dual-magnet generator mirrors that cutting head’s architecture, with two low-mass magnets aligned in a V formation parallel with the record’s grooves for accurate music extraction and stellar tracking.

The Micro-Linear diamond stylus is the key upgrade here — its long, narrow contact profile traces vinyl groove walls with microscopic precision, reading detail that elliptical profiles simply ride past, and it sits atop a tapered aluminum cantilever for lower effective tip mass. Signal is generated through Ohno continuous cast copper coils, and the well-damped billet aluminum body controls resonances for tight, accurate bass reproduction. Output is 3mV into a standard 47k moving-magnet input. Developed in collaboration with Allen Perkins.

MoFi publishes the same channel separation, channel balance and body weight for this cartridge as for the UltraTracker below it. That is genuine rather than a copying error — the two are rated to the same production limits. Where they differ is stylus profile, cantilever, coil material, output and compliance.

Features

• V-Twin dual-magnet generator mirroring cutting-head architecture
• Micro-Linear diamond stylus traces groove walls with microscopic precision
• Tapered aluminum cantilever for reduced effective tip mass
• Ohno continuous cast copper coils
• Well-damped billet aluminum body controls resonances for tight, accurate bass
• 3mV output into a standard 47k MM phono input
• 27dB channel separation and 1.0dB channel balance at 1kHz
• Threaded aluminum body — two-screw mounting, no nuts required
• Developed in collaboration with Allen Perkins

Specifications

• Type: Dual Magnet (MM) stereo
• Stylus: Micro-Linear diamond
• Cantilever: Tapered aluminum
• Coils: Ohno continuous cast copper
• Body: Well-damped billet aluminum, threaded — no mounting nuts needed
• Output Voltage: 3mV
• Frequency Response: 20–25,000Hz
• Tracking Force: 1.8–2.2g
• Recommended Load Impedance: 47kΩ
• Recommended Load Capacitance: 100pF
• Static Compliance: 40 x 10^-6 cm/dyne
• Dynamic Compliance: 10 x 10^-6 cm/dyne. MoFi does not state the measurement frequency
• Channel Separation: 27dB at 1kHz
• Channel Balance: 1.0dB at 1kHz
• Weight: 9.7g
• Colour: Dark grey
• Origin: Hand-built in Japan, aluminum housing milled in the USA
• Note: MoFi publishes no recommended tonearm effective mass, no replacement stylus and no warranty term. MoFi renders the stylus name variously as Micro-Linear, Micro-Line and Micro Linear across its own materials; we follow its website spec table