Thanks folks. Yes, I'm really enjoying the DIY aspects of this hobby. It's very rewarding to build something yourself and have it make great music.
These amps really seem to be delivering the goods. They are a good match for the kind of music I like to listen to - mostly jazz, folk, alternative, and electronica, but primarily with vocals. My servo open-baffle subs provide a great foundation, so I'm really only using these for around 70Hz and up and they do a fabulous job here.
I've been thinking about building a DAC, but I'm not convinced I'd be able to match, let alone exceed, the sound quality from my Terminator Plus. So I think I will probably do a tube preamp first.
@sns - good luck with your music server.