From my own experience, it is an absolute requirement that the specific tube linestage be tried with the specific solid state amplifier. Even with supposedly compatible impdedances and short cable runs, etc., the result of going from tube into solid state is quite unpredictable (most often in a bad way), than any other combination; I would be much more confident predicting the result of solid state feeding tube than the other way around. I am certainly NOT saying that tube feeding solid state doesn't work well, but, the combination must be tried first.
From a practical standpoint, you should also look for a tube linestage that can be completely muted while it is warming up or one that does not emit ANY noise when turned on and warming up, or the solid state amp must have a mute circuit. I have found that solid state amps sound their best when left on all the time or at least warmed up for a very substantial amount of time. Tube gear, on the other hand, warms up faster and really should not be left on all the time. That means that the tube linestage has to be turned on AFTER the amp--any startup noise could be nasty and potentially harmful to the speakers.
For what personal preferences are worth, I generally like linestages with 6SN7 tubes. There is a HUGE variety of these tubes so it is possible to tailor the sound of a linestage by choice of specific brand/vintage/model of tube. I haven't heard a 6H30 linestage I really liked (sounds lean and brittle to me). On the exotic side, I like linestages that use 310 tube -- warm, great midrange presence, but a little rolled off on top.
From a practical standpoint, you should also look for a tube linestage that can be completely muted while it is warming up or one that does not emit ANY noise when turned on and warming up, or the solid state amp must have a mute circuit. I have found that solid state amps sound their best when left on all the time or at least warmed up for a very substantial amount of time. Tube gear, on the other hand, warms up faster and really should not be left on all the time. That means that the tube linestage has to be turned on AFTER the amp--any startup noise could be nasty and potentially harmful to the speakers.
For what personal preferences are worth, I generally like linestages with 6SN7 tubes. There is a HUGE variety of these tubes so it is possible to tailor the sound of a linestage by choice of specific brand/vintage/model of tube. I haven't heard a 6H30 linestage I really liked (sounds lean and brittle to me). On the exotic side, I like linestages that use 310 tube -- warm, great midrange presence, but a little rolled off on top.