Fwiw - I bought a pair of MC601 monos and directly compared to my Krell 350MCX mono's to decide which ones I would keep. after A/B testing at length i heard a very very slightly sweeter sound from the Mac otw sonically no difference. I sold the Krells. I needed big power for the Maggie 20.7 which both have.
The stereophile review of the MC501 was very good especially the measurements.
https://www.stereophile.com/content/mcintosh-mc501-monoblock-power-amplifier-measurements-0
With that said....and the 20.7 have been replaced with Gryphon Trident II. (which are still in crates awaiting a dedicated room build). I will then be auditioning other amps such as Gryphon, Dag, and CH. They will be compared directly to the Macs. I am skeptical that I will hear much difference much like the Krell test, but we will see.
The stereophile review of the MC501 was very good especially the measurements.
https://www.stereophile.com/content/mcintosh-mc501-monoblock-power-amplifier-measurements-0
With that said....and the 20.7 have been replaced with Gryphon Trident II. (which are still in crates awaiting a dedicated room build). I will then be auditioning other amps such as Gryphon, Dag, and CH. They will be compared directly to the Macs. I am skeptical that I will hear much difference much like the Krell test, but we will see.