I bought and attached a HifiBerry DAC Plus for my RPi running Volumio.
The reason was less the quality (the default AudioJack output of the RPi 3B+ is actually not that bad IMHO), but that the output volume was so low. Whenever I switched to the Pi from other sources on my Stereo (CD, Radio, Mobile) I always had to walk over and turn up the volume. Inversely, when I switched from the Pi to any other source this frequently blew off my ears before I managed to turn the volume down.
With the HifiBerry DAC Plus I know I could have (substantially) more volume, but what I get out-of-the-box with Volumio is practically the same low level a I got with the RPi’s AudioJack. How/where can I adjust the “overall” volume of the DAC Plus? I would like to be on par with the other sources when Volumio’s volume dial is at, say, ~75%.