You might consider the Rogue M-150 mono blocks. 150 watts ultra linear or 90 watts triode. They are made in the U.S. and their customer service in very good. I am using with Martin Logan Summits that dip to 2ohms and are 90db. Used they are just a little over $2,000.
Tube amps vs solid state for large speakers
I am looking to experiment with a tube amp and currently use a tube phono-pre with a solid state amp. Problem is I am concerned that I wont be able to get enough power to drive my speakers with tubes, which are A/D/S L-1590 @ 8 ohm rated to 400W. Any thoughts out there? Also, what tube amps would you recommend to try out...under 2K used.