TechDAS Air Force V Turntable Lab Report

Lab Report

The Air Force V's own registration of 33.33/45rpm speed suggests a start-up of some 20secs with 'lock' finally indicated at 25secs, even though 'audible' stabilisation is achieved rather quicker at some 7secs. In this and in physical appearance the Air Force V looks remarkably similar to the Air Force III [HFN Sept '16], although the chassis plays host to a new and fully integrated motor assembly. The belt drive is close-coupled to a sub-platter/platter combination that weighs 6.7kg – some 3.3kg less than the III's alloy platter. It still employs a disc of polished glass beneath the platter, the pumped air escaping smoothly across its surface and raising the rotating mass by some 30µm.

However, while absolute speed accuracy is excellent at –0.02% [Graph 1, below], dynamic speed variations from the V are higher than those measured for all the costlier TechDAS decks. These use higher-torque outboard motors, the chassis-mounted drive in the V delivering a peak-weighted total W&F of 0.11%. In practice, the W&F spectrum is dominated by two ±6-7Hz wow sidebands, these also showing some DC drift.


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


Unweighted bearing rumble from DC-200Hz (black infill) versus silent LP groove (with vacuum pull down, blue; without, red) re. 1kHz at 5cm/sec

Otherwise, the V's simpler platter, with its soft foamed mat, is seemingly more effective at suppressing vinyl noise (through-groove rumble is –72.1dB versus –68.6dB for the AF III), although the through-bearing rumble is about 1.5dB higher at a still impressive –72.5dB (all DIN-B wtd re. 1kHz at 5cm/sec). The Air Force One [HFN Jun '13], Two [HFN May '15] and III have all demonstrated bearing/chassis modes between 30-40Hz and a single, low-level mode at 30Hz is also visible on the unweighted spectrum for the V [black/blue traces, Graph 2 above]. Levels of noise-like rumble are also lower via the V, possibly courtesy of the reduced platter mass and reduced incoming air pressure. PM

Turntable speed error at 33.33rpm 33.33rpm (–0.016%)
Time to audible stabilisation 7 seconds
Peak Wow/Flutter 0.07% / 0.04%
Rumble (silent groove, DIN B wtd) –71.3dB (–72.1dB with hold-down)
Rumble (through bearing, DIN B wtd) –72.5dB
Hum & Noise (unwtd, rel. to 5cm/sec) –55.1dB
Power Consumption 32-35W (5W standby / (25W idle)
Dimensions (WHD) / Weight 312x168x368mm / 17.7kg
Price: £12,500
Stella Inc.
Tokyo, Japan
Supplied by: Absolute Sounds Ltd
0208 971 3909