Mobile Fidelity - UltraTracker MM Phono Cartridge

A step up into serious moving-magnet territory: MoFi’s V-Twin dual-magnet generator paired with a nude elliptical diamond stylus and a well-damped billet aluminum body, with a 3.5mV output that suits any MM phono stage.

MoFi designs its cartridges by examining where a record actually begins — the cutting lathe. The UltraTracker’s V-Twin dual-magnet generator mirrors the layout of the cutting head that originally makes a record’s grooves, placing two low-mass magnets in a V formation parallel with the groove itself. That symmetry between cutting and playback is the foundation of the cartridge’s tracking ability.

Where the StudioTracker uses a bonded stylus and polymer body, the UltraTracker moves to a nude elliptical diamond capable of tracking complex passages with superb detail, and houses the generator in a well-damped billet aluminum body. The metal body controls resonances for tight, accurate bass and supports wide-bandwidth audio with extension at both frequency extremes. Frequency response reaches out to 25kHz and channel separation improves to 27dB. Developed in collaboration with Allen Perkins.

Because the aluminum body is threaded, mounting takes screws and washers only — no nuts to juggle above a suspended platter. Both are supplied along with a hex driver.

Features

• V-Twin dual-magnet generator mirroring the cutting-head layout
• Nude elliptical diamond stylus for tracking complex passages with superb detail
• Well-damped billet aluminum body controls resonances for tight, accurate bass
• Aluminum cantilever
• Wide-bandwidth response with extension at both frequency extremes
• 3.5mV output for easy matching with any MM phono stage
• 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: Nude elliptical diamond
• Cantilever: Aluminum
• Body: Well-damped billet aluminum, threaded — no mounting nuts needed
• Output Voltage: 3.5mV
• Frequency Response: 20–25,000Hz
• Tracking Force: 1.8–2.2g
• Recommended Load Impedance: 47kΩ
• Recommended Load Capacitance: 100pF
• Static Compliance: 35 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: Silver
• In the Box: Cartridge, 2.5 x 8mm hex screws (2), 2.5 x 10mm hex screws (2), metal washers (2), nylon washers (2), hex driver
• 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’s own manual describes the stylus as “Elliptical Micro-Line”, which conflicts with the nude elliptical given on its website and sell sheet — we follow the website