Sc: If your room is not too large 300B based amps should work well. Lots of different flavors of these amps, though, and they do not have to be soft/slow and rolled off @ the frequency extremes if you pick wisely. A pair of mono block "kits" getting some praise as of late are the "Billies" available @ http://www.diyhifisupply.com/ (think that they are around $1K delivered). If you can solder the kit looks to be easy to build. There is more info on them in the SET Forum @ AA. I have always been happy with current production Svetlana 300B tubes which seem to be readily available for well under $250/pr and would not spend the money for new production WE's (based on the pair that I tried) - the Svet's smoked them. Depending on the circuit they can also last quite some time (very long indeed in the Audion 300B amp which I just sold). If you decide to make the leap try to stay with a "real" single ended "triode" amp (it's worth the extra $, IMO).
How to pick your first SET tube amp?
I am curious about hearing one of these little amps on some new monitors I got, the Coincident Triumph Signatures. Coincident makes a beautiful pair of SET mono's, but at $3500 they're a little steep for experimenting with. Any recommendations for a good, entry-level pair of SET monos that would give me a taste of what all the fuss is about? I would like to stay at or preferably under $1500. What is the difference between the sound of the EL-34 based SET's and the 300B and other types?