So I have spent a whole battery playing with the AP200 today. I started with a factory wipe/ reset and its most possibly a placebo effect, but I found overall the sound was improved a little. I tested Apple Music and it worked well, even in offline mode. I will however say in Android Mode, the device is rather slow and has a delay when doing anything, either RAM or SoC issue. Pure Mode works fine with the odd HibyMusic dropping out and restarting itself.
May need a burn in (if it has capacitors?) to sound better.
Not sure, maybe... I hope so.
Any bigger on-ear/over-ear headphones to check with? Output impedance was claimed as 4,8 Ohms, which could be an issue with many IEMs.
I tried my old Sennheiser HD25s rated at 70Ω - For some reason sound tiny and crappy. Not too sure why, maybe they have die I haven't used them for a while.
Maybe there's a low gain/normal/high gain setting to help.
It has a High/Low gain option. Tried both, I found low gain then pumping the volume sounded a little better, but I'm a little confused how that works.
These are my current issues...
1) Can’t use the side buttons to adjust the volume when screen is off. Need to activate screen then volume works.
2) Can’t workout how to set it to “Line Out” mode.
3) I encountered some slight earthing/ digital (like a hard drive) type noise issue when no sound was playing and in Android mode only.
4) sometimes having issues with Play Store dropping account authentication and requiring a reboot to get working again.
5) The keyboard isn't very accurate while typing, not sure if its the OS issue, or a touch screen calibration issue.
6) Battery from fully charged drops pretty fast.
7) Can't find location of a user manual.
8) Some missing features from store HibyMusic. Hibylink, ReplayGain, Hide Lyrics.