Small or big tubes/valves for pre amp ?

I have had some correspondence with Don, he seam like genuine nice person and very helpful, but of course he will not talk down his own product, and nor should he.
As I know the the flavor of many nos 6922 and they can be very different, I have no knowledge about the 6SN7 family of tubes, have heard also that they are a bit more fragile than the smaller tubes and do not last as long.
I like the Mullard sound, but with detail, am allergic to thin/shrill sound.
Tone, decay, timbre and natural voices is something I listen for in the music, I find that many amps and speakers today can replay a woman voice perfectly, sometimes spellbindingly good, but male voices not so good, often sounding neck up only, no chest!

I have my dream speakers now, and with my solid state amp I have problem with Van Morrison for example, sounding too thin, but with my hybrid amp he sounds fantastic!
Going to a tube pre into a solid state amp, a Belles or Van Alstine I am hoping to get more detail and maybe a more euphoric sound, also my hybrid amp makes me listen to music for hours at a time, my solid state amp, not so much! 

Just to clarify, I like a bit more detail than I hear at the moment with my setup,  but don’t want the details thrown in my face so to speak, just want to be better able to follow different instruments in a classical piece for example, not detail for detail sake ;-)

Thanks for all your inputs, really appreciate it.
I live in a far remote area so no chance to listen to other gear, with a pre amp that uses tubes it would give me more chance to tailor the sound for my preference, my speakers are bbc speakers, so easy to amplify, they are 8ohm and don’t go below 6ohm, but they are very revealing in tone and timbre, tone, timbre and space I find tube do better than solid state, and by changing the tubes I can get closer to my sound ideal.
For power amp I had planned to buy a Belles sa100 that I can get at half price (demo) but have also heard very good things about the Van Alstine set400, will see what I end up with, wish there was a solid state pre that sounded like tube ))) then no need for replacing tubes;-)

This worries me a bit to hear, although I am no bass freak, I like tight bass, using a solid state power amp instead of tube power amp make any difference?