Roksan Attessa Turntable Package Lab Report

Lab Report

The Attessa is fitted with a high quality stainless steel/brass main bearing while the platter – a 10mm glass disc with a bonded, precision-machined alloy periphery – contributes a full 1.8kg to the deck's total 6.3kg weight. This well-damped platter comes up to speed over a leisurely 4-5 seconds with a fine absolute accuracy of –0.06%. Peak wow is a low 0.03%, the main component at ±4.5Hz, but peak flutter is distributed over a wider ±50Hz bandwidth and amounts to a higher 0.09% [as illustrated by the broadened main peak, see Graph 1 below]. Through-bearing rumble is also quite high at –63.5dB (DIN-B wtd re. 1kHz/5cm/sec) with modes visible at 1Hz, 7Hz and 96Hz, but the combination glass/alloy platter with its custom felt mat takes this figure down to a more respectable –67.4dB through-the-groove. In practical terms, this is the figure that matters.

The partnering uni-pivot tonearm is rather more substantial than it looks – a half-round ABS moulding plus aluminium top section – so the effective mass is also above-average at 14.5g and arguably slightly better suited to lower compliance pick-ups than either the Roksan Dana or, in particular, the popular Ortofon 2M series. The undamped uni-pivot necessarily offers very low friction and setup is very easy but its resonant behaviour is quite 'lively', possibly due to its numerous flat alloy surfaces. There's a low-Q bending mode at 65Hz followed by harmonics, twisting and other bending patterns at 165Hz, 260Hz, 460Hz and 670Hz, followed by a smattering of short-lived resonances above 1kHz [see Graph 2]. The more energy ploughed into this arm via the pick-up, the more these modes will be aggravated, so medium-compliance MMs will be favoured over low compliance MCs. PM

1221roksan.lab1

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

1221roksan.lb2

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

Turntable speed error at 33.33rpm 33.31rpm (–0.06%)
Time to audible stabilisation 4-5sec
Peak Wow/Flutter (Peak wtd) 0.03% / 0.09%
Rumble (silent groove, DIN B wtd) –67.4dB
Rumble (through bearing, DIN B wtd) –63.5dB
Hum & Noise (unwtd, rel. to 5cm/sec) –54.9dB
Power Consumption 5W (1W standby)
Dimensions (WHD, with lid) / Weight 432x105x353mm / 6.3kg
Price £995 (inc. arm and cartridge)

COMPANY INFO
Roksan
Rayleigh, Essex
Supplied by: Monitor Audio Ltd, Rayleigh, Essex
01268 740580
ARTICLE CONTENTS

X