VPI HW-40 Anniversary Turntable Lab Report

Lab Report

Thanks largely to the efforts of Technics, direct-drive turntables are once again in the limelight and while VPI's updated motor (a non-ferrous design with a claimed 2.68Nm/sec torque) brings the HW-40's 11.3kg alloy platter up to speed in a fraction over one second, it's not quite as silent as its Japanese rival [HFN Jun '18]. Nevertheless, VPI's rumble is lagging just 1-2dB behind the world's best with its HW-40 achieving –73.1dB through-groove (slightly poorer at –72.5dB with the LP weight in place) and –73.5dB via the motor/bearing itself. Absolute speed is bang-on with a mere –0.03% error and, assisted by the flywheel effect of the platter's peripheral alloy ring, speed stability is very good with peak wow a mere 0.02% and flutter 0.04% [see Graph 1].


Wow and flutter re. 3150Hz tone at 5cm/sec (plotted ±150Hz, 5Hz per minor division)


Cumulative tonearm resonant decay spectrum, illustrating various bearing, pillar and 'tube' vibration modes spanning 100Hz-10kHz over 40msec

The partnering 12in JMW Fatboy tonearm features a '3D printed' armtube and integral headshell mounted into a robust gimbal bearing assembly featuring 'Japanese ABEC 9 bearings'. Friction is very low at <10mg in both planes and there was zero detectable play in our sample. These are very fine bearings indeed! Furthermore, despite its length, the lightweight tube material contributes to a moderate 14g effective mass for the arm as a whole, while its variable cross-section (a chamfered square at the bearing to a rounded triangle at the headshell) pushes the first bending mode up to 130Hz. There are harmonic and possible twisting modes at 225Hz and 280Hz with higher Q, but more rapidly dissipated, modes at 470Hz, 550Hz and 890Hz [see Graph 2, above]. The frequency range of these sharp resonances is not dissimilar to that we've observed from various 'carbon fibre' armtubes, but they do look generally better damped by VPI's polymer/resin tube. PM

Turntable speed error at 33.33rpm 33.32rpm (–0.03%)
Time to audible stabilisation 1.5 seconds
Peak Wow/Flutter 0.02% / 0.04%
Rumble (silent groove, DIN B wtd) –73.1dB (–72.5dB with weight)
Rumble (through bearing, DIN B wtd) –73.5dB
Hum & Noise (unwtd, rel. to 5cm/sec) –62.0dB
Power Consumption 4-45W (4W standby)
Dimensions (WHD) / Weight 559x432x254mm / 15kg
Price (including arm) £15,000
VPI Industries Inc.
New Jersey, USA
Supplied by: Renaissance Audio, Scotland
0131 555 3922