There is a big difference between the (original) 3020 (a late 1970s amplifier, http://en.wikipedia.org/wiki/NAD_3020) and a D3020 (a new class-D amplifier). Let us be careful. I think HeavenNotes is referring to the 3020.
Rigth, it is vintage 3020 . Now I'm listening jazz with my HD 580 whith HD 650 cable uffff it sounds great!!!!!