Luxman PD-191A Turntable Lab Report

Lab Report

There are close parallels between this new PD-191A, its predecessor PD-171, and the earlier PD-151 [HFN Oct '19] which was one of the first Luxman decks to employ a new 'high torque' brushless DC motor. The motor is retained here and mounted directly onto a heavy, rubber-damped bottom plate, bringing the 5.2kg platter up to speed within 5 seconds via a substantial EPDM rubber belt. It's not uncommon to see a sub-1Hz drift with decks that employ a DC motor solution, but Luxman's PWM/PID speed controller clearly provides 'direct-drive standard' low-rate speed stability, seen in the sharpness of the main W&F peak [see Graph 1, below]. However, this same plot also reveals a ±8-9Hz high-rate wow amounting to a peak-wtd 0.06% which is unfortunate but not subjectively problematic. Speed adjustment of ±6% allows precise pitch stability to be achieved.

Luxman's sealed stainless/brass bearing assembly, with PEEK thrust pad and molybdenum oil, is familiar and achieves a direct rumble figure of –68.8dB (DIN B-wtd). The heavy rubber mat provides significant damping, reducing the through-groove rumble and noise to just –72.6dB. Meanwhile the partnering 'not quite S-shaped' LTA-710 tonearm offers an effective 256mm (10in) length, a 15g effective mass and exhibits a clearly defined main tube mode at 140Hz with harmonic/secondary resonances at 290Hz and 375Hz [see CSD waterfall, Graph 2]. Friction from the vertical knife-edge bearing is <15mg while the 'dial up' counterweight is precisely calibrated, under-reading by just 4% at 1g (1.04g) and 1% at 2g (2.02g). Just make sure you take time to dynamically balance and settle the arm before gently turning the circular indicator to read '0' at the 12 o'clock position. PM


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

Turntable speed error at 33.33rpm 33.34rpm (+0.03%)
Time to audible stabilisation 5 seconds
Peak Wow/Flutter 0.06% / 0.02%
Rumble (silent groove, DIN B wtd) –72.6dB
Rumble (through bearing, DIN B wtd) –68.8dB
Hum & Noise (unwtd, rel. to 5cm/sec) –62.6dB
Power Consumption 4W (4W idle)
Dimensions (WHD, inc. lid) / Weight 491x186x393mm / 26.4kg
Price £11,000 (+£1500 with LMC-5 cartridge)

Luxman Corp.
Supplied by: IAG (International Audio Group), UK
01480 447700