I would listen for an extened session with your equipment before making a decision.
I auditioned a Conrad Johnson CT3 SE, and the "tube" mystic just didn't get it with me. They cropped the top off detail and transients. Sure, they never sounded "bright" but that also means what were "proper" sounding sources were now robbed of richness and detail. This was NOT a cheap preamp, either.
The midrange detail that tubes are supposed to be famous for was not present to the level that I was pulled off the ship by the Sirens of Titan and into the sea. The sound was intoxication, but I don't often view the world drunk...or like it for long. The soft sound is permanent, too. A single twinkle or voice or boom sounded nice, but the complex sounds that make music were too blurred together and compressed for my tast. Tubes do best on simpler music.
SS units have converged on the best tube's midrange sound and at much lower prices, while keeping the highs, lows and dynamics. They sell far fewer tube units so the R&D cost is heavilly absorbed on small unit sales. Tubes JUST started to be able to drive high impedance cable any real distance with hybrid output stages. The bang for the buck is lower.
The mystical tube sound (at the real high levels of quality people speak of) are indeed in amps, not preamps and with the SET arrangement that yields little power and headroom(far less than Quatros will need) at reasonable prices.
So I would NOT follow the tube mystic without extended listening sessions and compare SS units on the same source material and over extended sessions with the same balance of equipment. I did just, this and am walking away from tubes in the sub 20K price range. SS is just so much better than it used to be that overall, I feel it is superior to tubes in most cases EXCEPT super efficient speakers with SET amplifiers and that's a long way from what a Quatros is, or ever will be.
So don't read about what you buy till you believe it. Go to a good dealer, take equipment home and LISTEN longer term to tubes and SS in the same price range and THEN decide if the tubes sound is for you. It can be, but at prices mortals seldom can afford.