file_mode=0770 to file_mode=0775 and
dir_mode=0770 to dir_mode=0775
Yep. That is the case! Now everything is working. And I'm almost happy

I think it should de added in future updates.
Thanks a lot for Your help. I appreciate it.
There're the few things I want to ask You:
1) I can't find support for *.dff files (only *.dsf). Is it possible to add this format in future builds?
2) I'm using Luxman DA-06 as a DAC. It seems to have native DSD playback option but my Linux knowledge is too bad to understand info on GitLab. Now i must switch DOP from "no" to "yes" in etc/mpd.conf to listen DSD. In othe case my DAC is not shoving DSD playback.
I've found this:
https://gitlab.denx.de/Xenomai/ipipe/co ... 30d576636c
https://lore.kernel.org/patchwork/patch/899686/
Is it realizable on DietPi? I'll be happy to test native DSD playback if You can help me with all this.
3)On early DietPi builds and Volumio I've used M.A.L.P to control MPD from my phone. Settings are still the same as before but it shows me "failed to connect" massage.
M.A.L.P settings:
Hostname or ip: my DietPi ip
port: 6600
These options are incorrect? Is there ani "conf" file where I can check it?
Anyway You've done a lot for solving my trouble. Thanks a lot again.