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?
Zaikesman: thanks; very informative. My gut said to wait on a SS amp purchase: I began to wonder if the older SS amp was the way to go. And if I'm buying new, why not go with tubes. I think I'll keep the Adcom around, though. It might be useful in a multi-channel setup powering a subwoofer. What sort of power in a tube amp do you think I need for the Energy Audissey A5+2s? What about tube amp configuration? Pentode, triode? Any particular features I should look for? What manufacturers make entry level 'acceptable quality' tube amps? Thanks for your help, Z.
Webnick, I'm not sure any more what the main thrust of your question is. Listen to some amps of both types if you can. Tube amps aren't made for the mass market, so quality will be at least "acceptable" or better, but sound and quality tend to be pretty comensurate with price until you get above the price range you're likely to be looking in. As for your present speakers, I'm not qualified to offer advice on powering them, but focus on sound quality, not watts. My point is that if you want the better speakers, get a better amp than an old Adcom - be it tube or SS - and I recommend either getting the speakers first or auditioning your amp options through those speakers if you plan on buying them later. The tube options you'll want to look at in your range will not be triode, and basic stereo amps don't have many features to compare. Let your ears be your guide. :-)
I guess I was trying to understand what makes a particular tube amp a quality tube amp. I think I understand now that you were talking in general terms, and that in general, tube amps tend to be of a higher sound quality than SS amps. I'll get to some local shops and start listening to tube amps. Do you have any reservations about three channel tube amps? Do you have any reservations about the Jolida tube amps?
Can't answer for Zaikesman, obviously, but I do have experience with tube gear including Jolida. Jolida do make some great products for the money they charge. Most are built in China as I understand (the company itself is based in MD). The quality is more on the scale of a mass-produced item rather than the more hand-built level that much of the higher-priced tube gear reflects. The Jolida amp I owned was their 302B and was the first tube amp I owned. It was well built but certainly did reflect that distinction I made. If I compare it to the Cary and Quicksilver gear I now use one could certainly tell the difference in quality upon examining both products. I found the Jolida to be immensely enjoyable coming from SS, and would certainly recommend them as a solid introduction to tubes that has pretty good resale value as well, though you may even like it enough to hold onto for a while. You can certainly purchase more refined, hand-built tube products that sound even better still, no doubt about it. You will likely have to add some more $ to your Jolida price tag though, and or buy used gear (which is not necessarily a bad thing). The Jolida 302B I had did yield much of the wonderful qualities tubes have to offer without a huge $ commitment. Eventually it made me yearn for more of what I loved about those qualities. Some of the things that will make the difference in price and quality of tube gear are just how well the amp is designed, the quality of the components used in the amp from capacitors, to transformers to attenuators to tube-sockets to wires and more. Also how well constructed it all much care went into the it point-to-point wiring or are printed circuits utilized...are the tranformers hand wound or machine wound and sourced from some other country. As far as three channel amps, I'm not sure if you are asking about Jolida's additional output for a subwoofer(?). I think the use of a subwoofer is a matter of taste. Nothing wrong with it if done right. The Jolida output (subwoofer-out) does not put out much power as I recall so going that route may not give all the punch of going through an separately amplified sub. Perhaps you may be referring to using a center channel, which I have no experience with, but understand it can also be done very effectively. Anyway, hope that input helps.

Yes, Marco, that does help. And I had been looking at Quicksilver as a matter of fact. Also VTL. Both companies somewhat close to (my SoCal) home. I'm open to older/used equipment but since I know little if nothing about tube amps, I am wary of buying the stuff. The Jolida 1703 is a three channel amp.