I vote for a tube line stage and not a tube CD or phono stage. Too limiting to a single source. Most people expect a tubed line-stage (preamp) to be placed after the surround sound processor and use a home theater bypass built into that pre, but if your processor is decent at letting the signal through unaltered then you can reap benefits before it as well. And a tube pre wherever you place it can handle multiple connections from CD players and turntables and dacs. Much more flexible. I guess what I'm trying to say is don't rule out putting a new tube pre in front of your surround sound processor. You might have good results doing that and connecting ALL of your other components to it for tube sound. Good luck.
