Help !

At this stage I have no idea how the drive was formatted but it worked

When that drive is connected to a Windows 10 computer just open the Windows File Manager, select "This PC" on the left if it isn’t already selected, then right-click on the icon or listing for that drive and select "Properties." Under the "General" tab of the box that will appear the type of file system it has been formatted with (e.g. NTFS or FAT32) will be indicated.

As I mentioned, Windows, JRiver, and for that matter any other program running on Windows will have no problem seeing and working with either format. The uncertainty (or at least my uncertainty) is whether the Vault can write to an NTFS-formatted drive that is connected to one of its USB ports.

Best,
-- Al

Schubert,

As you've probably figured out, it looks as though I may have misspoken when I suggested you could rip your CDs and then donate or sell the CDs.  Certainly some read the copyright law as prohibiting that, although I don't know that any court has directly ruled on the issue.  In any event, I apologize to you and the community for any confusion I created.

jimcrane, As I understand it copying to special Audio-CD-R, MiniDiscs or digital tape is legal since royalties were paid on them.  In that case you can sell or donate original CDs (you paid royalties twice), but copying to other media like data CD-R or HDD requires you to keep original CD (only one royalty paid).  Audio CD-Rs cost more than plain data CD-Rs because of included royalties. I have to keep all my original CDs since I ripped CDs to HDD.
This I found on RIAA website:

Copying CDs

• It’s okay to copy music onto special Audio CD-R’s, mini-discs, and digital tapes (because royalties have been paid on them) – but not for commercial purposes.
• Beyond that, there’s no legal “right” to copy the copyrighted music on a CD onto a CD-R. However, burning a copy of CD onto a CD-R, or transferring a copy onto your computer hard drive or your portable music player, won’t usually raise concerns so long as:
  • The copy is made from an authorized original CD that you legitimately own
  • The copy is just for your personal use. It’s not a personal use – in fact, it’s illegal – to give away the copy or lend it to others for copying.
  • The owners of copyrighted music have the right to use protection technology to allow or prevent copying.
  • Remember, it’s never okay to sell or make commercial use of a copy that you make.

The Acronova Nimbie will hold 100 discs. You load it up and let it work all night ripping discs to your server while you sleep. It's the least tedious way to rip a large collection. 

I gather the OP prefers Classical Music.  I second the suggestion of ripping them to a Hard Drive, such as the Bluesound Vault, but be aware that all the organizational systems can make finding Classical difficult.  They organize by the Composers first name, and inconsistently spell it from disc to disc.  Most Classical users are used to filing our physical discs by Composer last name.  So if you haven’t started copying yet, it is worthwhile to learn to edit the software before you start, so that each disc is entered in a way that makes sense for you.
  If the OP is retired, then this is a fun retirement project.  You will rediscover many CDs that you haven’t listened to in years and it could be a lot of fun.