Radiotron was good for me.

Nachbauer pushed outward from there also, here's an announcement page:

https://groups.google.com/forum/#!topic/rec.audio.tubes/swgQ... (his early links are long dead)

Here starts one preamp discussion:

http://www.ampage.org/homebrew.cgi?cat=sg&sb=&so=hl&page=989...

If you like, then here is the rest of that story:

http://www.dogstar.dantimax.dk

And don't forget this:

http://www.dogstarmusic.ca

With lost artists go lost arts.