I'm a-bed my portable amps and sources at the moment. UESF5pro and Grado SR60 with HD414 pads, silver interconnect cable, iRiver H320, Cowon D2, 1st gen nano and sansa clip as source.
Hands down winner, the XXS. Its just so smoothe, clear and full of live. Used with my H320, it is absolute heaven. Easily the best $170 I've spent.
My Xin Supermini, for some reason, doesn't seem to sound so good to my ears. I don't know, but although the bass is tight, the treble just lacks spark to my ears. I'm not sure the Xin justifies all the hype around it. Who knows, maybe its just me not being familiar enough with it yet. Thoughts of selling it as I tested it certainly are not a good indication.
I purchased this one: http://www.head-fi.org/forums/f42/ic...2004-a-350201/
Could it be just that I have a poorer version of the amp?
My soundrigor is a surprise act. Sounds to my ears more like a brighter version of the XXS. Certainly not as much detail, and the bass isn't as tight, but overall it is quiet close. In fact, I'm getting second thoughts about selling it. Works especially well with my iRiver h320.
The Storm B3 is like a poorer version of the Soundrigor. I think I may well sell it since I don't think it works well with the gear I have.