I am also thinking about the right preamp match for my Pass Labs XA 60.8. Current ideas are Pass Labs XP22 oder Luxman C900u or Benchmark LA4/HPA4.
What is you experience with Benchmark preamp, especially compared to Luxman C900 and other preamps you heard? I think the Benchmark has a very interesting concept concerning volume control, which I think is crucial overall.
thanks, Robert