Which preamp to go with pass labs x150.8

+2 for Aric Audio. As I’m typing,I’m listening to Aric’s Motherlode II,and a First Watt J2.  I find the combination pure magic. 

I have a PS Audio BHK pre amp that I sometimes use with my  X250 and some times I use my BHK 250 amp both sound fantastic the tubs in the BHK sound a little warmer to my ears when I am listening to Jazz, All so in my opinion both of these companies offer the best in the  business service after the sale.

@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?