Vintage

JVC’s direct-drive ‘coreless DC quartz-lock FG servomotor’, with a claimed starting torque of 1.4kg/cm, gets the 2.9kg platter up to speed within 2secs and, even after 40 years, this sample was still running to within –0.06% of 33.33rpm. Pitch stability is excellent, this deck showing little or no low-rate drift and a peak-wtd wow of just 0.03%. There are a series of higher-rate flutter sidebands [see Graph 1] but these only amount to a peak-wtd 0.05%.

Rumble is more... interesting. Tested via the spindle and motor core it amounts to –67.2dB (20Hz-20kHz, DIN-B wtd, re. 1kHz/5cm/sec) but it’s the unweighted spectrum [not shown here] that reveals what is either ‘cogging noise’ or a function of the corrective arm servo with a main peak at 90Hz (–68dB re. 1kHz/5cm/sec) and a series of smaller peaks at 62Hz, 67Hz, 71Hz and 75Hz (all circa –75dB). While these peaks are very clear on an FFT spectrum, none are especially obvious on the W&F plot [see Graph]. Moreover, JVC’s thick rubber mat helps bring the through-groove rumble down to a very respectable –72.9dB.

The partnering S-shaped tonearm has an effective length of 254mm and an effective mass of ~14g with the supplied detachable headshell. The arm’s servo system (with adjustable damping) may modify the behaviour at resonance but, with the electronics disabled, the arm shows a broad primary bending mode just below 100Hz. Other twisting or harmonic modes are seen on the CSD waterfall [see Graph 2] at 215Hz, 320Hz, 420Hz and, more significantly, at 580Hz. However, these resonances are quite limited and swiftly damped, possibly because the arm is otherwise free of traditional appendages such as a headshell fingerlift, mechanical bias compensation or yoke and ballrace. PM