With the new headphones, I've bought (Ultrasone HFI 15G) was to me the bass is too weak and the volume is no longer the way I like to like it. The sound of the headphones is good, but it clearly needs rock for my taste more oomph. The FiiO Amplifier is now everything is as it must be for me. Geiler bass, good volume. Along with the smartphone (HTC One X + 64GB) The whole thing is somewhat difficult to carry around. That's why I use my old iPod still like, when I'm out walking and will take no bag.
I'm not a hi-fi connoisseurs and can not compare with other headphone amplifiers to Fiio E12. For my purposes, the performance is optimal, and listening to music makes so real good mood.
