Tube preamp for Pass Labs amp


I am considering changing around my system and I am interested in knowing what (tube) preamps would be a good match to Pass Amps. Any suggestions? Less than $3000 would be nice new or used.
aronsss
I am runnning a Modwright SWLP 9.0se into a Pass X-250 into Totem Forests, they gel gloriously.
Aesthetix Calypso with NOS tubes. There's one listed for $2,500. I had one for approx. 3 years and regret selling it.