Wanted to install my entire music lib on an external drive and be able to access it while travelling. I have just installed Volumio 2 on a Raspberry Pi ZeroW with HiFiBerry DAC Zero. Muisc Lib converted to MP3 files on a 128 GB USB Pen Drive
It’s working well playing through the AUX input of my Caravans Radio. 
Welcome to Volumio Roger.
I trust that you’re not annoying your near neighbours when playing through Volumio at full volume 