amp -preamp combination question.

Can anyone explain to me what is the different between a SS amp/tube pre-amp combo Vs Tube amp/SS pre-amp combo?.I am planning to buy a krell pre-amp to match(cosmetic) with my cd player,but dont want to get rid of my 300B tube amplifier.
there are considerations of output impedance of tube pre amps and input impedance of ss amps that are important. if a tube pre has a high output impedance, it is looking for an input imedance of at least 50000 ohms. what is a high output impedance for a tube pre, probably 600 ohms or higher, i'm not precise on this number.

another issue is dc current produced by the tube pre coming to the ss amp. this could be trouble.

there probably are less isssues in the ss pre, tube amp combination.

i think you would want to listen to combinations to see which you prefer.
Of course this is not always the case and different amps and pre amp will make a monkey out of the following statements, but here goes: IMHO the tubed pres add air and dimension around intruments, widen and deepen the soundtage. Paired with a good SS amp that is quick gives punch, dynamics and bass extension. An all tube system will sound warm and mellow but may lack punch for driving jazz and rock and intense classical climax and that may be just fine for you. I think in general a SS pre with a tube amp may sound clear and clean but will sound constrained and will leave you unimpressed with the bass. In general my preferences would be 1) tube pre, SS amp 2)Tube amp and pre and 3) SS pre, tube amp. All that being said your source componenets will also make a big difference in overall sound characteristic. If you can listen to these combos in your listening room and go with what sounds good to you. That's really all that matters.
I had bad results when trying to pair SS Pre to Tube amp.. Much better match in my expereance with Tube Pre, SS amp.
I'd been using a tube pre with a SS amp for a few years before buying a tube amp. A cash crisis forced me to sell my tube amp and return to my old configuration. I forgot how much I enjoyed the dynamics and quick attacks of the solid state amp. The tube preamp I own uses 6SN7 tubes which produce a nice tone and mated with the solid state amp creates a big, bold, warm and dynamic sound.

I have tried many different solid state amps with this tube pre and only had trouble with one because of the impedance matching issues Mrtennis mentions. It was a beautifully sounding amp, but it had no beans with my preamp.
I have SS top of the line preamp with triode tube amp, Amazing combination, a lot of punch, you wouldnt want any more without breaking your ears (and that´s 12 watts)Clarity precision...

I never heard a tubed preamp I liked with my tube amps(maybe its just me), too mushy, undefined...

I now have a Resistor passive unit and it kills the SS preamp on clarity, silent backround, bass, and yes dynamics... The main problem with passives is making them work in your set up, but once you get it WOW.

Mrtennis has a point about DC current, It was recommended to me that I should place a coupling cap either at the input of the tube amp or at the output of the SS pre...
I hear Mark Levinson uses input coupling caps on his Amps...anybody know about this?
Loosing the resolution that a good tube preamp offers over almost any solid state is an unacceptable compromise for me. 25 years ago I ran solid state with a tube amplifier. It kinda helped with the tube amps I ran back then (to give a kind of fake improvement in detail by brightening things up a tad) but with the much higher resolution tube amps available now days the faults of even really good transistor preamps become rather obvious.

Once you've lost that resolution from the front end of the system, there's no way to get it back later!