Chord Hugo does that. I have HD 650 + Hugo combo and it's simply amazing. With Hugo, there's no trace of any veil. Hugo's best features are its transparent sound and amazing bass so I think it's one of the best pairings with HD650s. The bass hits hard and clear whilst mids and highs still sound awesome.
Sounds good, thanks. I have a BDA-1 Bryston on main rig, and for portable, a Fostex HP-P1 DAC/amp which is quite good with 650. I think 650 has enough bass as is, imo. The highs could be clearer, crisper, and more pristine.