MEASUREMENTS

I tested the Musical Fidelity M8xi with my Audio Precision SYS2722 system (see the January 2008 “As We See It”1). I first preconditioned the amplifier by following the CEA’s recommendation of operating it at one-eighth the specified power into 8 ohms for 30 minutes. At the end of that time, the top panel was very warm, at 109.6°F (43.1°C) and the heatsinks were too hot to touch, at 162.1°F (72.3°C). I then started performing my usual thermal stress test by running the amplifier at one-third power into 8 ohms for an hour. However, I cut the test short after 20 minutes, as the top panel’s temperature was already 118.1°F (47.8°C) and that of the heatsinks 172.7°F (78.2°C) and I was concerned that I would damage the amplifier. Despite the massive heatsinks along its sides, the Musical Fidelity amplifier doesn’t have quite enough thermal capacity for its power rating.

I looked first at the Musical Fidelity’s performance via