Right now I'm using Galaxy S3 -> UD100 -> Pico Slim -> 334. This is a great compact portable rig as long as you don't mind two things dangling off your phone.
The UD100 is a nice transparent DAC, although it does run down my phone battery a lot faster than listening from the headphone jack does.
The slim is a pretty good match for the sound signature you're looking for. I wouldn't go as far as to say the highs are harsh, but they do pair well with the 334. The Slim is not 100% hiss free, but the hiss only starts around 50% of max volume, and that is pretty loud with most sources. If you listen at low volumes I would consider it pitch black, but if you're incredibly sensitive to this I would audition before buying.
The 2Stepdance is even better in terms of hiss when used on high gain mode (music volume is louder in this mode, but hiss levels do not change vs. low gain). This amp has a smoother top end though, so probably not quite what you're looking for.
Thanks alot for the info. Seems like pico slim is the way to go for me. I don't listen loud so I am fine with 50% of the volume most of the time. Can you try and connect the USB to pico slim directly with S3? Will it work? I like the dragonfly dac but heard it don;t work with S3 connected directly due to probaly insuffcient power. Also can you show a pic of your gear, looks like I may need to follow your footstep. I am currenly using an inline volume controller now with fitear 334 to counter that hiss.
Also thanks Ue lover, temporarymyname and saraguie. I am also looking at the lockerton and I belive they have quite a few choice to buit one. Which built will give the best high (treble).