I have a Drobo 5N NAS that has an application that allows it to function as a media source. My OPPO 105 recognizes it, my Rokus recognize it, and my Marantz pre-pro recognizes it, and all can stream virtually any formatted audio file. They all can also show the album art if it is embedded in the file. My ipad and iphone also recognize it through the File Browser app, although they won't play WMA files, which is causing me to have to re-rip a handful of files.
I use Goldwave to add the art to the file, if it's not already there. Goldwave cost me less than $40, and it's had several no-cost upgrades since then.
I use this setup a lot for stereo recordings, and I'm particularly happy with how my OPPO handles the navigation.
Although the Drobo wasn't exactly cheap, and it wasn't cheap to populate it with hard drives, it's serves nicely as a source for audio and video. All of my