Tube Preamp with Solid State Amp?

 About 1 year ago I traded in my Parasound P5 on a Prima Luna Evo 400 preamp. Paired with my BHK 250 amp, the sound is fantastic. I run it balanced and it is dead silent. Great bass slam, a wider and deeper soundstage, and a very black background.  Plus it's built like a tank. Tube rolling is fun but can be expensive.  However, just changing the two front driver tubes will let you adjust the sound to your taste for not a lot of money.  I would definitely go with NOS tubes.  Just have fun whatever you do and always remember it's all about the music. 

Haven’t heard from the OP for awhile. Fairly safe to presume that the Parasound gear predated the 4th iteration of the Cornwall in your system. I am by no means knocking Parasound, as I think they manufacture well-engineered solid state gear for a fair price. While I think a tube preamp with solid state is a great combination for most systems, I am not sure it is for the Cornwall. Dick Olsher famously remarked that “the first watt is the most important watt”. You will likely listen to no more than 1 watt with that speaker in a small to medium sized room, so it better be a good one, or the other 249 in the case of the A21 are a waste.  Do yourself a favor and either use the A21 for a second system (driving an inexpensive inefficient bookshelf speaker perhaps), or sell/trade it. Get yourself a flea watt single ended DHT (2A3/300B/845) amp and find out what Olsher meant and what you’re missing. 

I’m running a Manley Shrimp with a McIntosh MC-352 and the sound is wide and open. To my ears sounded better than my Mac SS pre.  I have alway enjoyed a tubed pre and SS amps. I also run it through a Primaluna Dialogue HP tube amp. Those amps are wonderful sounding.

After growing my audiophile hobby with a fair amount of SS gear, I too finally decided to go the tube route... because of the music I listen to, and the relatively small size of my listening space... I don't tend to listen at high volume, but wanted to get an "enveloping" sound. 

I was getting set to pull the trigger on a Prima Luna integrated, and surely wouldn't have regretted it if I went that route... but wanting to also invest in a much better streamer, I realized my budget was taking a beating... 

Then I heard about the Heaven11 Billy amp, and really fell for the simple form factor, and the swiss-army knife approach to having a lot of input options and built in DAC. With tube pre and ICE  D-class  amplification, it really works paired with my Sonus Faber Signums to bring both detail and warmth. With the savings the Heaven11 brought, I could afford a used Lumin D1, which was really the missing piece to the puzzle. 

The Schiit Freya preamp (now the Freya +) allows instant switching between tubes and 2 other modes so you can see what's what regarding the tubes, and the tubes sound snappier, more detailed, and provide what I take as a more accurate presentation...my older version is very quiet and amazingly well made and sounds fabulous. The lack of "crossover" distortion and transistor harshness is gone of course from my single ended pentode power amp, the result being a more accurate musical presentation. Nothing "euphonic" or "smoothing", simply detailed down to about 58hz where my 2 under stressed SS RELs take over.