[Hardware and Software Interaction ?] Volumio 3.4xx + Kali reclocker + Piano 2.1 DAC, Dual Stereo output not the same


Hi
Here the Alsa mixer. MM is set to 46 (gain -20db?), others to 100.
I guess MM is for 1 set of RCA connection, the other for the other set.

Thing is, i never touched anything in Volumio / Alsamixer to have different levels on different RCA sets.
Weirdly, it is similar to this post https://community.volumio.com/t/alsamixer-volume/7238
(i am doing interpolation because of the mp3 white noise bug with Piano 2.1)

Is it possible to change the level in the Volumio settings (GUI accessible) or should i make change in some configs files of Volumio/Alsa ?

Have a nice day