Audio Research 150.2 or 300.2.....

Never owned one, heard  a 150.2 years ago when I was looking at amps.  Sounded very good.    A few years later I almost bought one used and heard they couldn't repair them due to no modules.  Not sure if that is still true but it scared me away. 

early class d by arc - not their best in solid state amps

earlier 100.2 class a/b materially superior sonically imo (i still have mine)

that said, i dunno why you are looking at any of these if you are powering la scalas