The headphone out is via resistors at 150 ohms for most of these. Low impedance phones get too bass rich for me. Beyerdynamic 250 or greater Ohm phones work real well here. My Senheiser HD 650 is hit or miss as the bass can get in the way. I do not have the HD 800 but if they are more like Beyer they may be a good fit.
r2
+1
Though it does work with my AD2000s