Blue Sound Vault

A lot of Node users have experienced significant improvements by adding a separate linear power supply so that might be something to explore.

On a related note, I have a Stereovox XV2 SPDIF digital cable that, like your Black Cat, was also designed by the late Chris Sommovigo so I’d think they sound more alike than different. I recently bought a used Acoustic Zen MC2 and was pretty amazed at the all-around improvement — not even close so maybe something you might wanna give a shot as well. Good news is if you buy it and it doesn’t work out you can turn around and sell it for little/no loss. Here’s one that’s exactly the same version/length I bought in case you’re interested…

https://www.usaudiomart.com/details/649951192-acoustic-zen-mc2-digital-coax-cable-1m/

Hope this helps, and best of luck.

Are you having it rip in FLAC or WAV ?   I believe there is a choice in the menu.    Funny thing about  the Vault, I ripped all of my discs, but I find myself streaming and using it's other features than playing my ripped files. 

The Vault does a lot for its price point but the rest of your equipment is pretty good and is revealing the limitations of Bluesound as a digital transport.  Spending a few hundred dollars will get you a noticeable improvement in streaming or playing files from a HD.  My Bluesound stuff sounded best in my mid Fi systems 

Thinking about it further, if I’m you I’d start saving for an Innuos Zen Mk3 that’ll undoubtedly boost your sound quality significantly rather than spending $$$ trying to make the Vault sound better.  They can be had around $2k used, and if you sell the Vault it’d offset a good chunk of that.  If feasible that’s what I’d do.  Here’s an example available now…

https://www.usaudiomart.com/details/649994436-innuos-zen-mk3-1tb/

Thanks everyone for your suggestions.  Steve