The iBasso DX50 player freezes constantly and cannot play music correctly. It almost made me go deaf. My DX50 came running on v1.16, the newest firmware. When I was listening to some tunes, I simply pressed the volume-up button a few times, the audio instantly jumped to 255 (max value) from 180. The unit then froze at 255 volume and kept blasting music into my ears. I was unable to volume down, or pause the player. I had to yank my IEMs out of my ears to avoid further damaging to my ears, take the battery out of my DX50 and force-restart the player. This happened multiple times since the 3 days that I have owned the player. It was playing regular old 320kbps .mp3 files when it did this. No doubt this thing has caused damaged to my hearing, as well as damage to my IEM's. And this is only the tip of the iceberg for software problems. The UI is as terrible as the AK100. When I reviewed the AK100 I said that the AK100's UI is worse than any Made in China POS there was. Now I have been proven wrong by iBasso. If you want to experience UI hell, purchase either one. Hardware defects - the player has parts loosely put together. It creaks when I hold down the bottom part of the player, like if the pieces were coming loose. When I got my Fiio X3, I thought it was ugly and had terrible UI (I mean, which idiot though it logical to press UP to skip track?). So I ordered the DX50 right away, thinking it would be much better. My conclusion now that I have both - X3 is light years ahead of the DX50, in build quality, sound, and UI. iBasso needs to just quit. Before they get a lawsuit on their hands. Or include a warning in their packaging that says "the player may choose to play at max volume for no reason other than our fail. May cause permanent hearing loss".