Depending on the gain of your preamp and amp, I still think the DI’s need close to 30 watts of quality power to sound their best. A friend brought over a First Watt SIT-2 to try with my speakers. It sounded great at lower volume levels but my Pioneer M-22 outclassed it at normal listening levels when listening to classical music.
If I were buying a tube-based amp, I would have to give a hard look at this one:
http://www.dsachsconsulting.com/custom%20kt88%20tube%20amp.html
If I were buying a tube-based amp, I would have to give a hard look at this one:
http://www.dsachsconsulting.com/custom%20kt88%20tube%20amp.html