Laboratory test report
Newport Test Labs first measured the frequency response, channel separation and output voltage of the Ortofon OM10 phono cartridge in order to see whether the powerful magnetic fields affected these aspects of its performance by changing the flux lines of the magnets inside or saturating the coils. The frequency response and channel separation are shown in Graph 1. You can see that the frequency response of the OM10 (black trace) is very flat between 30Hz and 20kHz, varying no more than ±1dB across this frequency range. This is an excellent result. Below 30Hz, the response rolls off to be 8dB down at 20Hz. Channel separation, as measured by Newport Test Labs, is shown as the red track on Graph 1, and you can see that at 1kHz, it was 17dB. This is 5dB less than Ortofon’s specification of 22dB. It may be that this particular (well-used) sample was out of specification, but may also be that the channel separation was adversely affected by the strong magnetic field… or not.
Newport Test Labs found the speed accuracy of the Mag-Lev Audio ML1 was exact at both 33.33rpm and 45rpm, with the turntable replaying a 3kHz sine wave recording at exactly 3kHz at 33.33rpm, and a 3.15kHz sine wave at exactly 3.15kHz at 45rpm. The lab found that measuring the wow and flutter of the Mag-Lev Audio ML1 was complicated by the fact that any air movement in the laboratory would cause the platter to ‘wobble’ slightly, which always increased the levels of wow and flutter that were measured. At 33.33rpm, Newport Test Labs measured wow and flutter at 0.13% unweighted RMS, and at 45rpm, it measured 0.12% unweighted RMS. Although these results are higher than those returned by most high-quality turntables (for which the lab usually measures figures of between 0.04 and 0.09%) they’re still low enough to ensure wow and flutter would not be audible. The lab noted that the platter was moving very slowly up and down at the time the measurement was obtained so you can achieve low levels of wow and flutter even if the platter is wobbling slightly.
Newport Test Labs also experienced technical difficulties measuring the rumble (aka signal-to-noise ratio) of the Mag-Lev Audio ML1, because the lab’s standard test technique involves using a mechanical device made in Germany known as a ‘Rumpel-Messkoppler.’ In this case, because the Rumpel-messkoppler was too heavy for the platter and also made of ferrous metal, plus using it requires making an alignment that can only be done whilst a platter is revolving, it could not be used at all. The lab instead resorted to using a far older measurement technique that required acquiring an acetate master specially cut with a ‘no signal’ groove. Using this test technique, Newport Test Labs measured the signal-to-noise ratio of the Mag-Lev Audio ML1 as being 75dB unweighted below reference level, that level being a 1kHz signal cut at a recorded velocity of 3.54cm/sec. This is the best result the lab has ever measured for any turntable and 2dB better than claimed by Mag-Lev Audio.
Putting the matter of the reduced channel separation of the OM10 cartridge aside as an issue requiring further investigation, there’s no doubt that—under ideal conditions—the levels of wow and flutter contributed by the Mag-Lev Audio ML1 are imperceptibly low, its speed accuracy is perfect, and the level of rumble is not only also imperceptibly low but also the lowest that Newport Test Labs has ever measured. That’s impressive… very, very impressive.
Overall, given the design principle, I can only say that the overall performance of the Mag-Lev Audio ML1 is a monumental technological achievement. Steve Holding