jagjag OP
Please help me by advising which amp will smoothens the highs
The ATC SCM40 are only 81db independently tested, so they’ll need a good >100watter or more to get them going.
You don’t need an amp with lots of current muscle though, as they have very easy impedance curve and -phase angle.
http://www.avmentor.net/reviews/lab/2014/atc_scm40/display/atc_scm40_impedance.jpg
So even tubes, mosfets or Class-D will drive them, just pick the amp you like the sound of. Parasound Hint 6 would be a great choice and it has a dac in it too.
Cheers George