Mine is from 11.2013 and I'm still using it. I was never able to achieve 10 hours, even when new, now I'm down to 2-3 hours - it was used only lightly. Any idea where to get a new good quality battery? From FiiO support I got this answer: "According to customs policy, the battery is not...

Yes, I'm running Windows 10. There is only the (ASIO) driver from 14.01.2015, which I already have. The distortion appears after several hours of playback. I don't think it's overheating, because a brief on/off switch fixes it for another several hours. Any recommended buffer/latency settings?

And what about the firmware?

I've never done a firmware update, I didn't even know there is a firmware in the E10K. Are sure it's firmware and not drivers? I have a similar problem with it as sidi0us has. After some time of continuous playback I get distortion, which gets worse if I let it play further. The only working...

There is a firmware update for the FiiO E10K? What does it fix. How do I determine which version of firmware I actually have?

I do, daily on my way to/from work.

Thank you for your interest.   No, sadly I didn't.   I rip to a single file with a cue sheet. I don't think there is anything wrong with my rips. They play without a problem on a PC (Foobar) and on my Rockboxed iRiver H-140 and H-10. When I verify the rips in CUETools, they are accurate...

Yes, Rockbox - I love it! I'm using it in dual boot on the H140 and H10. FiiO (and others) could learn a lot from Rockbox :-)

@TheGiantHogweed that's exactly, what I mean. I've deleted the cue sheet files to get rid of the gaps (no big deal, I listen mostly to whole albums), which means I have an album long "tracks", which means I have to use track position memory. Now I want to know what album I'm listening to and...

The most annoying (for me) is this bug - when playing FLACs with a cue sheet (the whole album as one file, tracks defined by the cue sheet) I get gaps between the tracks, not always but very often. That's very disturbing! More details are here...

Sorry, but I don't share you opinion on this.

IMHO it's not how long, what's important but if there are any bugs left in the final version ...

You could try the FiiO ASIO driver: https://www.dropbox.com/s/dd0uda7g9inz6bk/FiiO%20E10K%20ASIO%20Driver.zip?dl=0

That looks as if your card is dying ... You can try fsck.vfat or dosfsck under Linux.

It does look like a corrupt filesystem (or card). Have you tried to run chkdsk on the filesystem (in Windows)? You can check the card with H2TestW. AFAIK should be FAT32 or exFAT, NTFS is not supported