Tube Preamp with Solid State Amp?

Valvet is a good example of a manufacturer that subscribes to the tube pre/solid state amp school of thought. Can read some of my impressions here:
https://taww.co/post/190866808752/valvet-a4-mkii-amp-soulshine-preamp

I also used the Valvet Soulshine tube pre on the Bryston 4B Cubed, and it actually worked decently well as the Valvet has a relatively stout output, but the Bryston has a very low input impedance which isn't very friendly to most tube pres. There was some collapse of the soundstage at lower volume settings, and overall the Pass XP10 was better in that application. The specific tubes and circuit employed will have a heavy bearing on how well it mates with a particular amp.

That all said, and with the disclaimer that I am not at all a fan of tubes in general, I have to agree with other commenters that with a speaker as ostensibly tube-friendly as the Klipsch it's worth exploring a lower-power amp. Parasound amps are nice and clean but in my experience if you can get away with a lower-power tube or Class A solid state amp, you can unlock additional layers of musical nuance and enjoyment. Pass XA25 and Valvet E2 are a couple SS examples that could be magical and I would probably start there as the next step - get the most synergistic amplifier possible for the speakers, then look top optimize the preamp. You likely want something better than the Parasound at that point, but hard to say until you settle on the amp. (I'd also avoid preamps that have a built-in DAC unless you don't have the budget for a comparable outboard DAC.)

What type of music is this for, btw, and how loud do you need it?

After 50 years and 50 pre-amps  I have no doubt that tube pre and SS amp is best in average system .

That said , I have had two tube pres  blow up and  take  10., 000 $ of speaker with it . In todays money more like 15K .

I have Pass XA60.8 amps.  I had the Schiit Freya, I think its a good $ 600 preamp and much better with the balanced connections but it was no where as musical as my Decware CPS3.  The CSP3 is single ended and comes with a bit of hiss and humm. With the balanced connections the Freya was quieter but not quiet.
I bought a used Allnic L-3000.  Super super quiet, super detailed, clean strong bass and as they advertise kinda holographic.  
A really good tube preamp does not come cheap but even relatively inexpensive tube is different form SS and for me preferred.

Your needs and equipment sound very familiar. I am very familiar with the Parasound A21. I prefer the A21 for reasons I can't fully explain and its been my champion amp since 2016. I had cycled thru a few different combinations of solid state & tube models . For my current budget,  nothing has beaten it yet. As for SS preamps , I have tried the Parasound PHP 850(old!), P3(ditto), and New Classic 2100 pre-amps with varying levels of success in achieving the "low volume / full frequency, deep sound field" that I have always sought for my own ears. During this time I experimented with the half step tube buffer options (IFi Tube2 and Jolida SSX ) and eventually settled on keeping them in the signal chain full time. They run between my source (Cary DMS 500 DAC/Streamer) and pre. Both buffers added some of that additional space mentioned earlier but were not enough alone to fully engage my ears.  At my level of investment-SS preamps simply lacked these same factors to fully fill in the space of my listening room.But then the day arrived of trying my first tube preamp. The Vincent SA-1 finally ended the journey. The combination of the A21 and the Vincent is as close to what I can afford and be able to live with on a day to day basis.  The only thing that comes close to that is the Vincent SV-237 integrated (again a SS/Tube hybrid) in my second system.
 I did do some limited experimentation with tube amps. No matter the pre -the Prima Luna Prologue, which was a beautiful and well built amp , just lacked the low volume oomph on the low end. And for those of us in the desert Southwest, it also added an unnecessary amount of warmth to my already toasty room. And whenever a tube amp was in the equation it always-even at low volume- transmitted extra noise and hiss thru my ZU OMEN towers. 
Now this works for me and is not perfect!  I realize a larger investment may change the game. As I listen mostly at low levels and I enthusiastically utilize loudness and tone controls, I do run into some issues when my volume occasionally goes past 8:00 O Clock!  ( This is the portion of the program when somebody will pipe in on a impedance mismatch or a need to throttle down the Parasound's gain for more useful scale from my pre). Anyway hope that helps for perspective.

If you haven’t already, you should check out the Klipsch forum. I think that many who purchase high efficiency speakers do so because they highly value dynamics in the musical presentation, and they want to use them with SET amps. Klipsch and tubes are a magical combination. I remember visiting an audio store in the 70s and being blown away listening to a Sheffield Track record on a system with McIntosh tube gear and Klipschorns.  Solid state amps with Klipsch speakers can be quite good, especially with a warmer presentation offered by the likes of NAD or Parasound that takes some of the edge off an otherwise strident fatiguing treble. But most Klipsch Heritage line 2 channel systems I am quite certain are being driven by a tube amp.  If you decide to experiment with a tube preamp, I would suggest a used Audio Research preamp with a more euphoric sound rather than something like C-J with coloration, given that your Parasound amp is already on the warm side. I think you are wise however to try out a low wattage tube amp that can be a relatively low cost experiment (e.g., Decware, Coincident, Bottlehead if you have DIY leanings).