Just got mine ... some very initial "observations" (may not be original -- haven't exhaustively explored this or other related threads/sites) ...
FUNCTIONALITY (or lack of!):
- Wrong bit-rate/sampling-freq display for any-rate MP3 (seems to be stuck on "16bit/44.1kHz"). Maybe stuck with this display message for other audio fmts, too -- but even this new player (late Aug. 2011 manuf.) can't play high-rez FLAC, so I can't say for sure.
- Does not play APE files, contrary to to its pub'd specs.
- No way to defeat spectrum graphics.
- Getting into English menu not obvious and no English manual avail. AFAIK
Compared to souped-up QLS-QA350 and T51 ... the stock CK4 sounds cleaner (overall) with deeper/more-detailed bass ... BUT "slower" (sense of pace, etc. ... almost like slowing pitch control on CDP or turntable).
CK4's HO best of all the DAP I now have (tho' not enough output pwr, even for IEMs). But I prefer cross-feed w/HQ amping so HO is useless to me.
Worthless provided USB cable and AT C770 ear buds. When I saw the C770s retail for a whopping $25, I thought how much better that $ could've been invested into the DAP itself. Colorfly is supposed to be a 'high-end' brand -- don't they realize most audiophiles already have HQ 'phones and cables/accessories?! ColorFLY ... get your act together ... and button your FLY...
A lot more NEGATIVE criticism on the way as yet another worthless DAP burns in and gets put thru its paces ... so don't go too far away!
EDIT 1 (update: ~48hrs burn in):
-Couple of freeze-ups, one on a video. Once it would not turn on.
-The selectable "Digital Filters" (Fast/Slow) pretty much useless (I can't hear much diff.). Some more info on them in the CS4398 datasheet.
-The 0/180 phase-angle selector is a very welcome option ... but inconveniently located via "back-end" Settings menu. It should be right there in the "playing" window -- like EQ, Repeat, etc. -- as phase can vary from track to track.
-Does not get too warm during PB or charge... a good thing.
-Can be manipulated in one hand; single-handed grasp of CK4 seems secure/confident -- a refreshing change from T51/S:Flo2. Alas, with winter/ski/bike gloves ... unglove, pls.
-Photo and eBook viewing possible while Music playing. A good feature with Photo slide show option.
SONICS, etc.: Improving steadily as burn-in progresses ... yes, no reason to get T51 or QLS now for those in same-$ market ... maybe Fiio's long-awaited high-rez will be better. I paid about $180 USD for the CK4 -- I know this is a bit lower than normal, but at a "price": TaobaoFOCUS (USA) ordering is more labor-intensive.
Unit becomes quite warm during charging.
Runs moderately warm during operation. Probably hotter for more-CPU-intensive apps like video, FLAC and high-rez.
Edited by alphaman - 9/7/11 at 5:30pm