The Head One is a tube-rectified headphone amp with multiple impedance taps to complement a variety of headphones. Very nice sound, particularly with 'phones that tend toward the bright/analytical side -- I've had very good results with the HD700, HD800 and Beyerdynamic T1. Also works as a minimalist preamp with 2 inputs and separate line and sub outputs.
Wedge finish. Excellent overall condition; rating it a 8/10 primarily because I'm the second owner and do not have the original box. I'm including the following tubes:
2 6s45p sovtek 2 6s45p-e reflektor 1 ez80 RFT 1 ez81 Mullard 1 ElectroHarmonix 6CA4/ez81