Turntables, Arms & Cartridges

Comparisons with the original Concept turntable reflect some of Clearaudio’s modifications. Rumble, for example, is largely unchanged, with the through-bearing noise clocking in at –67.6dB (DIN B-wtd), the bearing itself a proven combination of a stainless shaft with bronze bushes and Teflon thrust pad. This bearing connects to a CNC-machined aluminium sub-platter with the 30mm-thick POM platter sitting atop, this providing sufficient isolation to reduce the through-groove rumble to –68.9dB. Audiophiles may wish to try an aftermarket felt mat – this will likely reduce rumble still further but its affect on sound will be less predictable. Speed stability is certainly improved over the original Concept, the new ‘TSC’ regime reducing the low-rate drift typically seen with DC motor solutions from a peak-wtd wow of 0.1% to 0.8% here [see Graph 1, below] – still higher than I’d like to see but at least the absolute speed accuracy is now bang on target (the –0.45% error reduced to +0.03% here).

The partnering 10in Profiler tonearm’s lightweight alloy tube is aided by its ‘naked’ headshell in maintaining a relatively low 10.5g effective mass and is very well engineered despite a slightly higher ~20mg friction through its vertical ballrace than the <10mg achieved from its horizontal sapphire bearing. The easily manoeuvrable ‘headshell’ also enables uncomplicated fore/aft/azimuth adjustment. The straight tube has a usefully high 160Hz main bending mode, and although the harmonics/twisting modes at 420Hz and 690Hz are of moderate/high Q, Clearaudio’s ‘spot damping’ ensures they typically dissipate very quickly [see CSD waterfall, Graph 2]. Modern tonearms, as illustrated by the Profiler, are a lot less ‘lively’ or prone to excitation than their forebears. PM

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

Cumulative resonant decay spectrum for the 10in Profiler tonearm (100Hz-10kHz over 40msec) showing main mode at 160Hz and brief higher modes