Recommended Preamp for Pass Labs XA30.8 and why

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.

The the new Micro ZOTL version with 3 inputs and remote is called the MZ2-S. I have ordered one and will have it next week. I already own 2 Micro ZOTL's and can say that it's the finest preamp I've ever heard. The only thing that's hard to believe is the price. you can't go wrong with a trial period. If you don't like it send it back, even the shipping is cheap because the thing weights next to nothing.

My XP20 does have a tape loop which I do use hooked up to a headphone amp. 

The Rogue Audio RP-5 tube preamp fits the bill.  Plenty of inputs and a great MM MC phono stage, plus a processor loop and outputs for headphones.  I am positively thrilled with mine and I have a;ways had tube preamps.  It also is remote controlled and is dead quiet, even with the volume all the way up, no hiss whatsoever.