Headphone amps are all the rage these days and Headroom has the game locked with their online retail store offering all the top cans as well as their whole line of amplifiers. Positive Feedback checks out Headroom's Millett tube amplifier and says this:

Their addition of tubes is not a gimmick—the tubes added flavor and liveliness that brought me closer to the music. They won't turn chicken shit into chicken salad, but they will "open up" your MP3 files and older CDs.

Hey, chicken salad is what tubes are all about. At $649, the Millett slots in as the most expensive amp in their "desktop" line and below their much more expensive Max line with a top price of $4k. That lower box is a separate power supply and, naturally, you're able to roll tubes to your little heart's content.

Headroom Millett Tube Amplifier Review [PFO]