Congrats on the Humboldt purchases. I've owned the Stern / Heisenberg combination for a while and think is incredible. From what I heard of the Humboldt at Munich, it's much the same. I would add to the previous comments that the sound is very "saturated" and as such, very different from the somewhat dry Audionet sound of other models (although I owned and liked the MAX power amps). It is also a very dynamic sound - even at low volumes, it demands your attention. The low noise floor and lack of any harshness means, though, that it never becomes tiring.