Modwright LS/PS 36.5 or Pass Labs XP-20?

I hope you picked the Pass. A contrarian, I feel solid state phono and line amplification upstream from tube mono blocks preferably in balanced mode brings out the best sound, the quietest noise levels. I know nothing about Modwright but Pass is a real company. Their service technicians rotate as designers so you have great support. 

ivanj, Modwright is a real company as well and makes very good components

Why not look at Rogue as well? I own both Pass and ModWright and they're both real companies; that's some funny stuff there... just saying. Both are great conpanies and it's not uncommon when you call either, you're talking to the men themselves. You can't go wrong with either brand. Best to try both in your system and not take any advice from others. Good luck.