I have just downloaded Volumio 2.31, set output device to Allo Piano 2.1 and Dual Mono and in the volume options I have set Mixer type to None and also noticed that Max volume level is set to 100. I also turned audio sampling on to re-sample to 32/768
Out of interest I activated SSH and had a look at the alsamixer and noticed that the Master Volume was set to 46 (-20.00 db gain), the Digital and Subwoofer settings were also set to 46.
Is this correct as I understood that messing with alsamixer loses bit perfect reproduction (although I know re-sampling also does this). Or is this a Volumio setting?
Theoretically, if you use Alsamixer with hardware Volume, the transmission is still bitperfect, and the DAC uses its internal volume control.
In any case, I don’t see the point of re-sampling to 32/768 : this is the best way to loose bit-perfect, and furthermore the DAC can support only 24/192…
To achieve the best sound possible do this:
Enable hardware mixer
Set volume to 100 (from now on you can control the volume, some people report best results while at 100, but IMHO you can safely adjust volume without loss)