The Audio-gd NFB-15 has a lot of output (1.8 watts at 50ohm) and is $250. I use the older NFB-12 with my HE-400 much of the time and it sounds excellent with zero noise. Not portable though (but why would you walk around with the HE-400).
This combo for roughly $600 (new) is unbeatable IMO.
In good condition- lettering paint is fading in a couple places and some minor scuffs, nothing serious.
I applied some electrical tape over the edges of the pads to add a little bass. I can remove if seller wants- does not affect or harm the pads.
Looking for cash so no trades at this point.
Paypal only (fees included). Free shipping in CONUS only, sorry no international shipping.