The PA2V2 is  a good amp, Nice Value ($56.00) on EBay (Bids) back in Sept. they are going for around $70.+ when I checked a week ago. For higher end headphones it probably will not suit Your needs, sometimes it pushes the high's a little to high for My preference, the midrange is pretty good and the bass is only as good as the song was recorded (Zune, IPod) just not enough drive for bass hungry headphones. I have a pr. of GRADO 225i's and when I use them with My portable cd player I hear the difference in the overall sound! The Power switch & Volume control are to close together, You can turn the volume up to high by accident (Big Hands) without knowing until You turn the amp on. I have played with the gain screws but I can not find My tonal zone.  Maybe it's just Me but I love overall music quality and this amp has served it's purpose for My 1st portable amp, I just need more. This is a good amp for lower end phones and louder music!