Which preamp to go with pass labs x150.8

@mbmi - Have you heard the Audio-gd and what preamps are you making your statement against? Also, the reviewer offers zero context as to what against that preamp is the best ever he's heard

What a silly statement. Explain all the Hybrid integrated's on the market today and that are selling quite well. Rouge, Pathos, McIntosh, PL, Unison Research, Canor Audio, Mod Wright, Circle Labs, Vinni Rossi.

I do not suggest a tube preamp with any SS amplifier,as it is not a good match.

Are there any rules with matching power amp with a preamp?

I know about input and output impendence, where power amp should have at least 10x bigger input impendence . 
But what about input sensitivity of the power amp?

Asking this because I have XA30.5, driven by Primaluna Evo 400 preamp, and have slight problems with total gain. Primaluna has 10db of gain, Pass has 26db, and I have to use XLR attenuators between those two since music is just too loud, I can't go beyond 9 o'clock on volume pot (tested several position of attenuators, and on Pass XLR input they are totally transparent, no change in quality, just 10db less gain). 
Preamps usually have at least 10db gain, and power amps around 25-30db. 
So is input sensitivity of power amp something to check also? 

Agree with @jjss49 depends totally on what sound characteristics you’re looking for and how they match with your amp.  What pre are you using now?  I wouldn’t even consider purchasing a preamp until you’ve heard the amp in your system and identify more concretely what you want in a preamp.  Just my $0.02 FWIW. 

@runwell  "I do not suggest a tube preamp with any SS amplifier,as it is not a good match."

Have you had a tube pre and SS amp in your system; if so what were the components.  I have a Modwright LS100 tube pre and KWA100SE solid state power amp in my main system, sounds just fine.