Pro-Ject Debut III S Audiophile turntable Lab Report

When it comes to engineering a turntable/arm/MM vinyl-playing solution to a price, few brands can match Pro-Ject for experience. This is reflected in the well-rounded performance of this £325 combination with its acceptable –66.7dB (through-groove) and –66.6dB (through bearing) rumble, and absolute speed that’s some +0.25% fast. The latter is inaudible but extends the deck’s ‘lifespan’ as its AC synchronous motor will inevitably slow – rather than speed up! – with age and use. Drift is minimal and so is low-rate wow at some 0.03%, but some higher-rate flutter sidebands, amounting to 0.07% (peak weighted), are in evidence at ±25Hz, ±50Hz and ±100Hz [see Graph 1]. The motor is sufficiently ‘torquey’ that start-up time is a usefully rapid ~3secs.


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 8.6in alloy tonearm offers a low/medium 9g effective mass that suits the moderate compliance of the Ortofon OM10-based pick-up. The gimbal-type bearing, with sapphire points, is derived from the arm fitted to the Pro-Ject Essential III [HFN Jan ’17] and offers a reassuring combination of low friction (<20mg) with minimal spurious play. The original straight alloy tube displayed a fairly ‘lively’ series of resonances and this S-shaped version is no less complex in its vibrational behaviour, albeit slightly better damped overall. The main bending mode comes in at a low 75Hz with harmonics reaching out to 175Hz, 240Hz and 315Hz and with higher-Q modes at 450Hz, 660Hz, 750Hz and 1.5kHz potentially having some subjective influence over the midband [see Graph 2]. The latter are very similar to those recorded for the Essential III tonearm so probably relate to common features, including the bearing and/or flat, pressed headshell. PM

Turntable speed error at 33.33rpm: 33.42rpm (+0.25%)
Time to audible stabilisation: 3sec
Peak Wow/Flutter: 0.03% / 0.07%
Rumble (silent groove, DIN B wtd): –66.7dB
Rumble (through bearing, DIN B wtd): –66.6dB
Hum & Noise (unwtd, rel. to 5cm/sec): –56.0dB
Power Consumption: 3W (1W standby)
Dimensions (WHD) / Weight:   415x118x320mm / 5kg
Price: £325 (inc. arm and cartridge)

Pro-Ject Audio Systems
Supplied by: Henley Audio Ltd, UK
01235 511166