Australian Hi-Fi

LABORATORY TEST REPORT

Readers should note that the results mentioned in the Laboratory Test Report and/or displayed in graphs in this report should be construed as applying only to the specific sample tested.

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Newport Test Labs measured the speed of the Mark Levinson No 5105 and reported that instead of rotating at exactly 33.330 rpm, it was rotating at 33.334 rpm.

This is shown graphicall­y in Graph 1, where the blue dashed line running horizontal­ly across the centre of the graph shows the mean speed of the platter, absent of any wow and flutter effects.

Graph 1 also shows the variations in speed around the mean, usually referred to as wow and flutter, with the red dashed line showing the sum according to the IEC-386 2-Sigma standard and the purple dashed line according to the IEC-386 Dynamic standard.

Graph 2 shows the same data as Graph ===1, but this time as a histogram, and you can see that the bars are very tightly clustered around the mean, so variations in wow and flutter are very low.

As for the wow and flutter figures themselves, expressed as percentage­s in the normal manner, Newport Test Labs measured it using the CCIR standard as 0.09% unweighted and 0.06% weighted. Measured using the DIN standard, the lab reported results of 0.15% unweighted and 0.08% weighted. Measured using the Australian standard, Newport Test Labs measured wow and flutter as 0.06% RMS unweighted.

These are all excellent results.

Noise (rumble) was also very low, as you can see on Graph 3, where Newport Test Labs measured it as being around 87.1dB below a reference level of 3.54cm/second, measured via a German-built device known as a ‘ Rumpel-Messkopple­r’ that attaches directly to the spindle and allows noise and rumble measuremen­ts to be made without interferen­ce from surface noise, which occurs when measuring using a test LP. Again, this is an excellent result.

Overall Newport Test Labs measured outstandin­g speed accuracy and stability, as well as low levels of wow and flutter, along with an almost complete absence of motor and bearing noise. Excellent performanc­e indeed! Steve Holding

 ?? ?? Graph 1: Speed accuracy.
Graph 1: Speed accuracy.
 ?? ?? Graph 3: Rumble.
Graph 3: Rumble.
 ?? ?? Graph 2: Wow & Flutter.
Graph 2: Wow & Flutter.

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