@ronkent I've owned the Diablo 300 during a year with my 3.7s and didn't like the presentation at all.
Its was pretty harsh sounding and the bass was lean.
I now use a Vitus SIA-025 Mk2 which is class A, this integrated is in a different league and drives my 3.7s much better with finesse and i do have a deeper bass now and it is full body.