Revolver turntable Lab Report

Lab Report

Our sample of the Revolver appears to be of a slightly earlier vintage than the deck tested in Hi-Fi Choice in 1985, although that published lab report does refer to a previous iteration of the LP spinner running +0.4% fast and incurring a total peak-wtd W&F of 0.29%. In practice our sample was running a full +2% fast, an absolute rotational speed of 34.0rpm which will be audible as a quickening of pitch, often mistaken for a 'pacy' sound quality [see Graph 1, below]. A deck running at 33.33rpm will sound slightly sluggish by comparison, but motors will typically slow with age, not speed up, so the absolute speed error here is probably caused by the manufacturing tolerance of the pulley (or platter). I suspect that all early Revolvers are likely to have 'revolved' a little quicker than they should...

Otherwise, Revolver's AC synchronous motor gets the 1kg platter up to speed within 3secs. Peak weighted wow & flutter, at 0.27%, is as high as recorded 35 years ago but is sufficiently complex to be almost noise-like in character (so the deck will more likely sound 'soft' or 'hazy' than 'fast', as reported in HFC 1985 and by our reviewer in 2019). The –100Hz flutter sideband is clearly revealed, though the +100Hz component is off the right-hand side of Graph 1. Bearing rumble is poorer than average at –64.4dB but the combination of rubber 'pig', attenuating noise rising through the spindle, and air-filled 'Starmat', lifting the LP clear of the platter, results in a very acceptable –68.1dB through-groove rumble (all DIN-B wtd).

The bearing/chassis modes up to 20Hz and dominant 100Hz peak are also visible on the unweighted rumble spectra [black/blue traces, Graph 2 below]. PM

120vintage.lab1

Wow and flutter re. 3150Hz at 5cm/sec (plotted 5Hz per minor div.). Deck is running 2% fast

120vintage.lab2

Unweighted bearing rumble from DC-200Hz (black infill) versus silent LP groove (with Pig and Starmat, blue infill) all re. 1kHz at 5cm/sec

Turntable speed error at 33.33rpm 34.01rpm (+2.03%)
Time to audible stabilisation 3sec
Peak Wow/Flutter 0.12% / 0.15%
Rumble (silent groove, DIN B wtd) –68.1dB
Rumble (through bearing, DIN B wtd) –64.4dB
Hum & Noise (unwtd, rel. to 5cm/sec) –52.2dB
Power Consumption 6W
Dimensions (WHD) / Weight 420x130x360mm / 5kg
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