Thanks for the replies, Barry.
I also found this vu meter clock that has a mic that powers from a USB:
https://www.youtube.com/watch?v=KZ7IUGOoQW4This is very interesting and nostalgic stuff for me. Back in the 80s before I got really sucked into this hobby, I thought the more bells and whistles and lights a component had, the better it sounded!
I have used so-so displays (via PC screen) with music player software such as Foobar or Audacious, but real lcd displays are so much better!
Looking at Amazon and eBay ,it looks like I'm not the only one interested in this stuff, there seems to be a whole subculture and niche market for these things.