After 2 hours of listening with my favorite test tracks of song my initial impression with this amp are as follows:
High = sweet and clear
Mids = clear tonal sounds
low/bass = tack and not muddy
Playing Clay Aiken Album "Tried and True Album"
Song: Can't Take My Eyes off You
The bass was fast without muddiness, the trumphet playing was so sweet and clear. I heard the breath of clay aiken that eventually gives emotion to the song. Whew!!! comparing this with my Fiio E12, Cayin C5 was a clear winner in all aspect a very nice portable amp!!! Don't take my word for it
I suggest you go to Audio Amplified and test this amp. Also bring your portable amp for comparison. I bought this without hearing/testing it, I just relied with the thread in head fi . org
here is the site
http://www.head-fi.org/t/729545/the-new-cayin-c5-portable-power-houseGear use:
X5 Dap
Cayin C5 Amp
and Senn HD 650 and it sings even in low gain setting the bass boost was also good