You might need to give a little more information as to your purchase. I would prefer using a tube preamp and s.s. amp, but you might also want to try the newer tube ARC equipment; LS 8mkII,16,25 and VT100mkII. You will be surprised at what you hear if setup correctly; I wouldn't think that those combinations would be too mellow. I think the answer to your last question is "it depends on the equipment you are deciding on." I have found that by using a better preamp with the same amp made a significant difference, in terms of transparency, depth, detail, etc. Let your ears decide. Hope that helps. Good luck.
Tubes? OH YES!!! But where? Hmmm....
I'm right now running Vandy 1Bs with an aragon 24k with vertically biamped dynaco st70s. I'd like to know if the soundstage will change significantly if I switch to tubes in the preamp stage and get a solid line amp. I don't really want tubes in both stages as it becomes too mellow for me. What are the differences in having tubes in the amp stage and tube in the preamp stage?