I heard the A3 driven by an Aavik (Group Denmark) Class D integrated amplifier. The sound was powerful but soul-less and the system did not sell me on the speakers. Amp synergy is going to be extremely important with your speakers to make them as enjoyable as possible.
Since they need a soul along with above average power hence the suggestion for a lush tube preamp with 6SN7 tubes (tube rectifier can also help) as well as a clean Class A or AB power amp.
If you want to stay Class D the best most soulful sounding amps I have heard are from AGD , specifically the Audion. Really nice sound that should complement the A3s. Good Luck !

