Folks, I'm finally getting my pair of Magico A3s delivered to my home this Monday (Labor Day). I am planning to follow David_Ten's advise and test several amplifiers at home. I have a Marantz AV8805 and a NAD M27, so I will be initially driving the Magico A3s with the the AV8805 and the M27. My sound system is also used as a surround system for watching TV and movies.
Most of the discussions so far have centered on integrated amps. Given that I have the Marantz AV8805, I think that it makes sense for me to use a regular amp, rather than an integrated amp, to drive the A3s. I welcome suggestions that won't break the bank. I have a friend who has many different tube amps (including vintage ones), so I will ask him to lend me some of them, to evaluate how they sound with the A3s.
I have to confess that when I was auditing the A3s at the store, I did a fairly extensive A/B comparison between my NAD M27 and a SPL s800 2 channel amp, both driven by a Marantz AV7704, and I could not discern that much of a difference between them. This tends to lend credence to the axiom that "an ideal amplifier should act as a pure gain." Thus, as long as both amps are operating within their specified ranges, ideally, there should be little differences between them.