Hi all,
I ran into an issue with my X3 2nd Gen that I was finally able to solve after 2 weeks, so I wanted to mention in here in case anyone else runs into the same problem. (I would have figured it out much sooner if I had simply taken the time out for full trial & error!)
I had been using my X3 2nd Gen for roughly 2 weeks with no issues, while using a Kingston 128GB class 10 micro SDXC card (that I had the player format before using). Then the FLAC files I was listening to started intermittently stuttering (not skipping) for no apparent reason.
It would occur at random, usually between 5 and 30 seconds into playing a FLAC file (which mine are all 24-bit, but vary from 48KHz to 192KHz), but sometimes not until around 60 seconds. The battery was always either 4/5 full or completely full. I had read on another thread here that some other FiiO players exhibited this stuttering issue if the FLAC file's attached image was too large, but the ones for my files didn't
seem to be.
I played with all of the player's settings (including performing a factory reset) to no avail, and also updated the media library a few different times. I tried removing and re-inserting the micro SDXC card, which at first seemed to solved the problem, but then the stuttering issue creeped up again.
As a last resort, I temporarily removed all of the files from the micro SDXC card and had the player format the card again, and then moved the files back (and updated the media library).
This solved the stuttering problem.
I now know what may have caused this to occur. I had completely forgotten (because it just didn't seem memorable at the time) that I had used the player's 'delete whole folder' function to delete a folder off of the card (followed by updating the media library). Since this was the only 'new' thing I had done, I think this led to the stuttering issue. Going forward I'll delete folders / files using the computer connected to the player instead.
Hopefully this saves someone here the anxiety I experienced!