I run Pass Labs X250.5 with Audio Research LS-25 linestage, balanced.
Sounds great. No issues.
I did call Pass Labs and spoke to a tech there before buying the amp just to make sure there were no problems running this combo and gave all the specs of my preamp to Pass Labs tech. He said that my ARC preamp should be an excellent match with the X250.5 and as far as I can tell, he was right.