Quite a fight with Aurlaic ark mx+

[hkphantomgtr]

Yeah, using USB external HD/memory stick as source of music files will give you the worst sound.  The best sound is using the internal storage.
Decreasing the latency needs you go to CMOS to change some setting.  There are some steps listed in here https://www.snakeoil-os.net/Manual/.
Have fun!

Thank you for the reply. Unfortunately using the internal SSD did not change anything. I did not hear any improvement in sound quality either. The sound is not the issue here anyway. It is always nice if it could be further improved but I'm happy as it is.
CMOS? That makes me think of battery Is not that hardware stuff? I tried to search for CMOS in the manual but found nothing.
In music player - alsa configuration. Is there something I could try there, with lower buffer or something?

CMOS is the fundamental hardware menu which you only can find it after you pressed the "Del" key properly while booting your PC.  The setting here is very crucial as it affects how the OS and softwares run seriously.
Shutting down unnecessary job of CPU and USB, setting the right values of RAM and CPU, and etc, are the entry of "better" sound.  Otherwise, tweaking software only just like building a fancy house on a wrong ground.

There are many related and detailed discussion in different forums, maybe you can get some ideas from different forum first.  Have Fun!