I think I want a tube preamp

Although the MiniMax does invert polarity we have found that it sounds best hooked up normally + to +, - to -. Your mileage may very and you can try and switch the + to -, but others have said they like it hooked up the normal way. I prefer it this way in both my systems.
You never know if the recording engineer recorded the material in phase or not. Does the amplifier invert, CD player? who knows, to many variables.

Thanks for all of your input. I'll have to do more research on the MiniMax. Does anybody know if the Quad 24 has a remote? Not a huge deal, but convenience is an issue. I'm not too worried about polarity inversion, I can't hear it in my room (unless I use headphones, and even then not every time). The high output impedance could be an issue. My Cary amp doesn't have the highest sensitivity. I already have to crank my Linn preamp past it's unity gain to get realistic volume in my small room. A high output impedance preamp would make for an even worse voltage transfer...

Why do you want a tube preamp? The best preamp is none at all. I think you should seriously think about checking out the Placette linestage (active or passive). What you want is neutrality and transparency, and in my experience nothing matches the Placettes. The active is a bit on the pricey side, but the passive and the volume control (only good if you have a single source component) are bargains!

Ditto on the Minimax. At the price point it is a very good value and what I love as well is the fact it doesn't take up much space.

Patekswiss, I generally find a little bit more body and dynamics preferable to stark transparency that can be just a bit too lean in many cases, just another point of view.

The Minimax, definitely changes the lower part of male and female voices, thinning them out somewhat, taking away the lower body, lessening the sense of presence, and realism. Listening to old Capitol recordings of Dean Martin, then Ella on Verve, is very revealing of this timbral change. Having said that, its not a tremendous flaw for such a low price. But, I try hard not to go completely over the top on a piece just because it is bargain priced. The Mini, with its stock tubes is too forward, with a touch of an emphasis on the 1st and second harmonic, making it too bright for my (again that is my) taste. I compared it directly to the Belles 21A, back and forth, with the NOS tubes in the Mini, and Mullards (in place of the $8.00 GE's) in the Belles, and it was not much of a contest, and clearly, in favor of the Belles. I certainly would say that the Belles for $2500. is as remarkable of a value as I have come across, in the same way the Mini is for $1250. Belles has very little identifiable personality in that price range;it is transparent but not at all thin, offering very good dynamics. The Mini is a value unheard of not that long ago. Listen to both. Of course this is all amp, speaker dependant, for all comparisons as is usual. I was (in favor of Belles) using the 350A Belles, and Von Schweikert VR-4 HSE's. Wow, such a fun way to spend 2 or 3 hours. I love this hobby! As usual, this is IMHO.
Good luck, and good listening.
Larry