Recommended Preamp for Pass Labs XA30.8 and why

conspicuous absence of any Pass pre-amps. 

I own an XP-20 and I rank it as the finest pre I've ever owned. Better than a CJ Premier 17LS2 I once had. With the Pass pre, solid state vs tubes is no longer either an issue or a consideration. 

conspicuous absence of any Pass pre-amps. 

I own an XP-20 and I rank it as the finest pre I've ever owned. Better than a CJ Premier 17LS2 I once had. With the Pass pre, solid state vs tubes is no longer either an issue or a consideration. 

I believe that Linear Tube Audio's MicroZOTL is a very special headphone amp / preamp.
Both TAS and Stereophile also have very positive reviews.
But with only two inputs / no remote / DC power supply.....
Hope I’ll have the chance to demo one in home in the future.

Because of space limit, I can only consider Pass Labs' SP10.
Actually I also considered Pass Labs' INT-60 integrated when I bought the XA30.8.
Pass' preamp has no HT bypass in or fixed record/tape out, so it can't be used with a headphone amp.
I would have purchased the INT-60 instead if not for the lacking of some preamp functions.
And I remember that lots of people recommend to mate tube preamp with solid state power amp.
I hope I can find other brand to match Pass perfectly.....

Pass xa30.8 is a robust and full sounding amp. It is not quickest though. I would suggest to get a preamp that is fast! Linear tube audio is a good option. So is CJ and ARC. Any preamp that slows down the proceedings a bit to favor tonal fullness or bloom should be avoided with these Pass amps.

Welcome! eddiekuo

you cannot go wrong w/ Aesthetix, ARC or CJ.
At this price-point and level of performance, listen to the models of interest prior to buying.