Tubes v. SS: can you mix and match?

Gentlepeoples - I was under the impression that a tube pre was always mated to a tube amp. Likewise, a SS pre would be mated to a SS amp. Of course, different makes and models of pres and amps could be mated, but I thought tubes should stick with tubes and SS should stick with SS, and never the two should meet. But this doesn't always appear to be the case with some of you. So, when and how are tubes mated with SS? Is it just a question of what sounds good? Are there any parameters at all?
The Energy A5+2s are 91db efficient. VTL is a Manley (and son) operation, if I recall.
Webnick, I was not trying to say "...that in general, tube amps tend to be of a higher sound quality than SS amps" - both can have their strengths and weaknesses, and I don't like to generalize sonics as far as 'tube sound' or 'SS sound' types of characterizations. I wasn't clear whether your question was about build quality or sound quality, but all I was trying to say is that tube gear is a specialty product, not made in the hundreds of thousands for general consumption, and will likely have acceptable build quality. My comments about quality being roughly comensurate with increasing price, at least in the sub-several-thousand-$ range, apply to both sound and build (beyond a certain point, you're into luxury cache goods, where all bets are off and image, status, and fetish play equal roles to sound and build quality).

But some brands off especially good value while eschewing fanciness, and VTL and Quicksilver are prominent among them as far as made-in-USA goods go. I can't comment on the current Quickie offerings, but I have heard the VTL ST-85 sounding extremely good with SS preamplification powering 6 1/2"-woofered small floorstanders, so I would certainly give it a listen with the Veritas 2.3's if you're so inclined. (BTW, David Manley hasn't had anything to do with VTL for a number of years, or for that matter the company he founded after he left VTL, Manley Labs. VTL is run by David's son Luke Manley plus Luke's wife Bea, and Manley Labs is run by David's ex-wife EveAnna Manley; David Manley had gone back to Britain or Europe the last I read, and I don't know if he has any industry involvement now. His design concepts do seem to continue to influence both companies to a fair degree, if not always in the same ways.)
I see, thanks. I'll research both VTL and Quicksilver and see if I can audition their stuff. Thanks, again. Whether to tube the pre or the amp or both remains a good question for me. The simple upgrades I've made so far have really improved the sound of the stuff I have now. I appreciate the comments of all of those who have responded.
Why not? It's a good bet that the music you hear has been through many transistor circuits during the recording and disc mastering process, so even if your equipment is tubular you can't attribute its sound to that feature. Maybe it's good for other reasons.
I do know people who have tube amps and SS in the same room. One fellow in particluar has the Mcintosh 2102 tubed amp (100 wass per channel) and he also has the a six channel SS McIntosh amp, for home theater. what is most amazing is the differance in how each of these brnd new amps can sound, in the same room, and wired through the same speakers (only for the sake of comparison). Especially for music listening the 2102 sounds really fantastic. Based on this experience i bought myself a 2102. Anyway, i think this thread has gone the old, well trod route of SS vs tube. I think the qustion was one of routing one through the other. I doubt you can hurt anything.