ATC tends to suck power like there is no tomorrow. I used Nilai class D to power my ATC, and it sounds pretty good. Class A or tube is suboptimal for these speakers. These amps are just not having enough damping factor.
ATC SCM40
With ringing in the New Year, I am thinking on trying the ATC SCM40 speakers. This is a huge speaker budget plunge for me but before I make a final decision, I want to see what you think on this model? Currently I have the Vandersteen 2ci
which they sound great powered by an Adcom GFA-5500 amp and a Rotel RC-995 preamp.