As the name implies, the $4,100 ($8,200/pair) MC501 is a mono amplifier that delivers a healthy 500 watts of power into two-, four- or eight-ohm loads. The McIntosh proprietary output autoformer technology allows for full power at a variety of impedances and helps to reduce distortion by keeping output devices operating in their optimal range. This means that the MC501 is perfectly happy driving any loudspeaker you choose to connect to it. The amplifier is also designed to protect those valuable loudspeakers with its Power Guard circuitry, which keeps the amp from clipping and damaging drivers, specifically the tweeters. Lastly, McIntosh has designed the MC501 to protect itself via the sentry monitor circuit, which insures that the output devices never exceed their staggering 100-amp-current limitation.
After spending some time listening to the MC501, I began to understand why McIntosh has so many devotees. From top to bottom, it did everything extremely well. The treble was detailed and airy, presented in a relaxed manner that drew me in to the music rather than pushing me away. The midrange was as smooth and textured as anything this side of a single-ended triode, only not quite as euphonic, erring on the side of accuracy. Bass grip and control were powerful and authoritative, but also musical and capable of extracting detail in lower frequencies, which are often missed by lesser amplifiers. I can't imagine ever yearning for more power than the 501 is capable of producing. Even when playing at what seemed like rock concert levels, there was always plenty of room left on the power meter.
Aesthetically, the MC501 is pure unadulterated McIntosh, which means you either love it or hate it. Personally, I love it. Styling aside, it is a beautifully constructed amplifier that should last a lifetime and then some.
Read The High Points, the Low Points and the Conclusion on Page 2