Famous high power heavyweight power amp from Crown
Unusual circuit topology makes for an interesting amplifier. Severe distortion at low frequencies on both channels even at 1/4 power. Distortion seems to be proportional to output voltage rather than frequency or load impedance which is very unusual, and constitutes mainly even-order harmonics. This may give the MA5000 series their characterisitc sound. At clipping at 40Hz (clip limiters disabled for the test), the flattened wobbly crests of the waveform suggest significant power supply ripple and undersized reservoir capacitors.
Update 23/01/2012 - Other engineers have been unable to reproduce the distortion we witnessed on the day of the amp test on other similar amplifiers. Despite the distortion being visible and identical on both channels of the amplifier, it is possible the amplifier under test was faulty. We would welcome the opportunity to test another amplifier and update these results. This would give us the opportunity to show full photographs of the internals and oscilloscope readouts, which was not possible on the day of the test.
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All results taken with sine wave input into a resistive dummy load of 8, 4 and 2 ohms (where applicable), two channels simultaneously driven (unless otherwise stated), at the threshold of clipping. These results should be considered maximum 'continuous RMS' power ratings (>5 seconds). Distortion measurements, labelled THD%, are taken with an HP8903A audio analyser (80kHz Bandwidth). |
Manufacturer | Crown |
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Model | MA5002VZ |
Weight | 35 kg |
Power to weight Ratio1 | 121.0 W/kg |
Notes | Severe Distortion at 40Hz, clipping with lots of power supply ripple. 2R measurement drew 40A @230V from the mains. Mains Voltage at 4R was 235V, and at 8R was 239V. 30-04-2010. |
Manufacturer's Website | http://www.crownaudio.com |
1 Power to weight ratio is calculated by taking the average of the power measurements at 4 ohms, multiplying by the number of driven amp channels, and then dividing this value by the weight of the amplifier.
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