With Fiio x3 I use Patriot LX Series 128GB http://www.amazon.com/Patriot-128GB-Transfer-Speeds-PSF128GMCSDHXC10/dp/B00SNLIG5O/ref=sr_1_1?ie=UTF8&qid=1447488940&sr=8-1&keywords=patriot+128gb+micro+sd+card&pebp=1447488943672&perid=0G95YSDZNBA9KB4AJC0D

.dsf vs. .dff   For my Fiio X5 I can use only .dsf files,  Now I have to convert .dsf to .dff for Xduoo 

you are nothing but a fraud (A. L. Webber Jesus Christ Super Star) I bought X5 as a X3 substitute, and before that I had a Sansa Fuze (with Rockbox software) – it is still in working condition (after 5 years).   As for me there was three main CONS of X5: Absence of bass/treble correction...

I have a question to Fiio about warranty - MP4nation denies to ask my question about idle button on my new X5. What have I do?

you're a magician! Thank you very much James! I have completely forget about reset button, because due to silicon case usage. Now X3 is working.   after all there are only two issues: 1. gapless playback, 2. sometimes X3 did not recognized .cue files, which foobar recognizes, for...

Now I have to send it to China for repair - I have bought it from mp4nation. My previous mp3 player Sansa Fuze (with rockbox) still working from year 2009 - very well that I was not presented my old Sansa to someone after X3 buing. Yesterday x3 just stopped to turned on with the full battery...