MoFi UltraDeck+M Turntable Package Mastertracker


MoFi's Ultra 10in alloy tonearm has an effective mass a little over 30g so, to avoid an arm/cartridge resonance that falls within the warp range of an LP, users will need to ensure any ~10g pick-up has a dynamic compliance that's <25cu, and ideally around 15cu. Unsurprisingly, the supplied MasterTracker pick-up is designed for the task, offering – by typical MM standards – a relatively low 13cu dynamic compliance, pushing the arm/cartridge resonance back to a relatively safe 8Hz.


At the recommended 2g, tracking performance is excellent for a low compliance design, this pick-up with its 'Micro-Line' stylus clearing a 70-80µm groove pitch and very tough +18dB modulation (315Hz lateral cut, re. 11.2μm) at 0.75% THD. Output is better than the specified 3mV at 3.9mV/5cm/sec.


Frequency response curves for the MasterTracker MM, (–8dB re. 5cm/sec) lateral (L+R, black) versus vertical (L-R, red)

The frequency response shows a high treble boost at 12kHz but the MasterTracker's 'V-Twin dual-magnet generator' is evidently very symmetrical, as evidenced by the matched L+R and L-R traces. The same is true of distortion vs. frequency (not shown) – typically ~1% from 20Hz-2kHz and never rising above 4% (–8dB re. 5cm/sec) at 20kHz thanks, in part, to the –5dB/20kHz roll-off here. Nevertheless, the symmetry of response and distortion on lateral and vertical cuts is superb, promoting a highly uniform 'colour' front-to-back and left-to-right across the soundstage. PM

MoFi Electronics
Chicago, USA
Supplied by: Karma-AV Ltd, York
01423 358846