Picked up the HD800's today. They are cooking with the MCD201 headphone amp on repeat. Quick listen revealed them to be more resolving, airy and open sounding over the HD650's. Tonal balance is a little lean and on the skeletal side since the bass is yet to come out and play. They may need some time to loosen up or perhaps the MCD201 is not going to cut it with these 300 ohm headphones which sound like they are tough to drive so far. The volume has to be set over 70% on the mcd201 to get adequate level.
They do sound like they have lots of potential though since the mids and highs are exhibiting exceptional tonal purity.
These are serious cans for sure and will most likely require a headphone amp up to the task. I'll order the Ray Samuels The Raptor tomorrow.
I'll follow up in a few days of additional break in.