Uber
The USB port on the Vault2 is for playback into a usb DAC not for attaching HDs. I had also tried initially attaching a HD to it.
I have added a NAS to my system and both my Vault2 and Node2 recognizes it. I use the Bluesound app to play files from it. It shows up as a separate folder in the Libraries section of the app. With a little fiddling you can also transfer the contents of the Vault to the NAS, so all my music shows up on one folder.
After perusing the Bluesound help files and actually trying it I can confirm the Vault 2 does indeed recognise and playback music from a local USB drive inserted into the back of the unit. You have to connect it to the second port down not the top USB port. It then shows up under your navigation drawer as usb, click it and you can access the music contained via the folders option.
Between this and accessing NAS ( which I have also now cracked, Win10 setup being the issue) it makes the Bluesound Vault 2 a very powerful and versatile option for the grand sum of $1000 to $1200 depending on what deal you can find.
I have had it 18 months and only just now figured out it can do a lot more than I ever did with it....doh!

