ELAC Miracord 70 turntable Lab Report

As ELAC says, any similarities between this new Miracord 70 and its ‘anniversary’ 90 deck [HFN Jul ’17] are superficial. The latter employs a low-torque DC motor driving the periphery of a 6.2kg alloy platter while the ’70 drives a sub-platter, with a 2.6kg glass platter atop, via a more conventional AC motor. Peak wow (and drift) are actually lower than with the ’90 (0.02% vs. 0.05%), but flutter is higher thanks to a pair of ±20Hz sidebands [see Graph 1], bringing the peak total to 0.1%. Ironically this is the same overall figure recorded for the ’90 although the through-bearing rumble is very slightly worse in the ’70 at –67.1dB vs. –68.5dB (DIN-B wtd, re. 1kHz/5cm/sec), probably because the ’70 lacks the ’90’s jewelled thrust pad. Checking the through-groove rumble with and without the felt mat reveals an improvement of around 1dB when an LP (a flat LP) is placed directly on the glass – so it’s worth experimenting here.


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

The partnering J-shaped tonearm features a semi-permanent headshell (held in place by a couple of small bolts, permitting some slight tweaking of azimuth) and offers an effective mass of 12g, making it suitable for a wide range of pick-ups. The cumulative resonance spectrum [see Graph 2] shows a low-level series of main bending/twisting modes from sub-100Hz to 200Hz with more energetic harmonics at 335Hz, 355Hz and, strongest of all, at 485Hz. These upper bass/midrange modes are quickly dispelled, suggesting the mix of alloy and steel in this arm’s design does, indeed, modify its resonant behaviour. Otherwise, bearing friction/stiction is extremely low at <10mg vertically and ~20mg horizontally while the gimbals are well adjusted and betray the minimum of detectable free play. PM

Turntable speed error at 33.33rpm: 33.29rpm (–0.15%)
Time to audible stabilisation: 3sec
Peak Wow/Flutter: 0.03% / 0.07%
Rumble (silent groove, DIN B wtd): –66.0dB
Rumble (through bearing, DIN B wtd): –67.1dB
Hum & Noise (unwtd, rel. to 5cm/sec): –56.9dB
Power Consumption: 5W (2W standby)
Dimensions (WHD) / Weight: 465x140x365mm / 11kg
Price (turntable/arm/cartridge): £1000

ELAC Electroacustic GmbH
Supplied by: Hi-Fi Network
01285 643088