What are the best sounding albums that you can buy digitally to put on your Volumio player?
Well, most classical recordings sound amazing, but much of the popular music mastered since the mid-nineties suffers from the “Loudness War” (http://en.wikipedia.org/wiki/Loudness_war), which can result in ear-bleeding distortion. Percussion instruments are the worst affected in my view, with cymbals having an awful sound.
You can find out what recordings have been mastered well at the Dynamic Range Database (dr.loudness-war.info/). Look out for the albums that are tagged green.
So, what can you do?
You can either:
Look out for non-remastered CDs manufactured before the mid-nineties (not all of these sound great as some of the early eighties masterings have too much treble) - CDs can be found cheaply on ebay and charity shops
Buy vinyl and digitise them. even modern Vinyl is mastered better than digital versions
Here are some great sounding recent CDs that I’ve found:
Ray LaMontagne - Trouble
City and Colour - Little Hell (A little loud, but sounds pretty good)
Katie Melua - Call Off the Search