04-16-15: TubegrooverQuicksilver V4 is an excellent suggestion and according to Mike Sanders, SE model has superior SQ to XLR.
Quicksilver has the option of using the KT150 in both the V4 and Silver 88. Both suberb sounding with this tube.
Also checkout Carver Crimson 350 and Primaluna Dialogue Premium HP.
I was seriously considering QS V4 but THANKS to a lousy BM dealer, I purchased ARC Ref250 with ZERO regrets.