If I'm looking for "Tube Sound", why would I put a Tube Pre in front of a SS amp?


I'm purposefully not specifying speakers as I would like to know in general terms the arguments for and against. So, to the degree that speaker characteristics could also influence the choice, please  explain.  FWIW, I do not know a phase angle from an impedance curve so I will try and educate myself as we go along.  Hopefully, others may benefit too.
finsup
Tube pre with a SS power amp is a great way to drive power hungry speakers and get that great tube midrange and high end and a solid bass.  I have a cary slp 05 and classe ca2300 driving some Thiel 3.7s.  Nice wide and deep sound stage, very natural sounding.  Not edgy or fatiguing at all.  I would recommend this combo (tube pre ss power) to any one.  Just make sure you pay attention to the output impedance of the pre and the input of your power amp.  Need to get a good match.  
Well, I can offer an opinion of sorts. Having run all SS for years (Classe, Perreaux), eventually moving away from HiFi for a bit. Upon returning several years later, also started to experiment with adding a tube pre. First, a Quicksilver inserted with the Perreaux (not a good match), then a Bedini and finally a Levinson 23.5. I liked the sound (which is what matter, no?) I continued my quest while building my main system which now comprises an ARC LS17se and a Levinson 333 into Shahanian Hawks, the mating seem to do everything well from Rock to Jazz to classical and back to Folk.

Currently looking to upgrade the ARC to a 5se and move the 17se to my second system. So you can say I am hooked on the tube/SS combo.
I use a tube Pre (Ayon Eris) and SS Power Amp (Pass x150.8) and it sure works for me.

I note that Rogue Audio build integrateds that use tubes up front with Class D power modules - I have not heard them but they are well reviewed.
Using my Manley Steelhead to drive newly acquired pr. of Pass 160.8s to my Avalons. Out of the box; the 160.8s had the best control of the bass that I have heard with the Avalons. Day (3) soundstage is wide, deep, layered. Midrange is to die for, highs are getting cleaner and starting to  shimmer. Bass is more articulated (micro & macro) imaging is superb. Last bit of palpable imaging and air that I suspect that I would get with tube amps is the only thing I could want yet; but superior bass control is what I will keep. I have been looking into NOS tubes. Not sure what various tubes will bring; but can hardly wait since this will be a 1st for me. So far I am definitely happy with my "divorce from Spectral " Instead of hyper details, I still have the details but everything sounds natural, No listening fatigue!! Sounds great at low, normal, High volumes. We are having our first "cool" spell in the Midwest. Amps keep listening room at 75 degrees!