Pros: size, power, sound
Cons: battery life, jack inputs
well i have had some cmoys, and a miu diy amp but none come close to this.
i recently recieved some Shure SRH440's and they sound best amped, and this amp pairs beautifly with them as it is very neutral albeit with a slight hint of warmth.
first off build quality:
very small and stylish, with metal casing and plastic body it is light and feels very nice in your hands. the volume knob is fairly tight and has some plastic to protect you from accidently turning the volume up when its in your pocket. blue LED tells you its on, red tells you its charging.
it comes with a mini to mini cable, a silicone strap to attach it to your DAP, and a mini usb cable to charge it. very nice package from Fiio.
battery life is said to be 10 hours, i have not tested it but i have ordered an upgrade battery, any Nokia BL-5B battery will fit, which is a nice feature.
very neutral with only a slight hint of warmth, i found no channel imbalance at low volumes like with the cmoys and DIY amp. if you just want more power to your headphones then this is the amp for you. it doesnt add or take anything away from your music. the soundstage is average i think (slightly wider than normal but nothing spectacular)
the bass boost is a very nice feature, as it doesnt cause bleed into the mids, its impact is mainly on the sub-bass region, which is good. with the Shures its nice to have a little bass boost sometimes. it wont make your headphones bass slam but you will hear more sub-bass,
High power/low power - High gain/low gain
i use this on low power and low gain and at volume level 2 is sufficiently loud for most use. (the voulume goes up to 8) so i think this amp will power most headphones with dignity,
This amp is amazing for the price, the only downside i think is that the headphone output jack becomes loose over time.
another great product from Fiio, i am very pleased with this amp. i would highly reccomend it,
sorry this review was written in a hurry.