Exploring Preamp options for the Pass XA25


Please feel free to share preamp options for the XA25. I presently have an Acoustic Research LS-3 and am not sure this is the perfect combination. The Pass Headphone preamp is one option that I'm considering. Tube preamps?
128x128coachpoconnor
I have 100 hours on a Herron VTSP-360 and it's settled in and opened up.  It adds tube magic and really shows what the XA-25 can do.  Speed, power, dynamics, and finesse without breaking a sweat.  
The Backert Rhumba is a splendid match with my XA-25. I get pretty much the same sonic qualities as wlutke above with his Herron. The XA-25 is a great match with tubed preamplifiers, IMO!
I have the PS audio bhk pre with my FirstWatt J2. Sounds great. However, I may seek out a Pass pre after new year. 
These are my list of recommendations so far.
Pass Labs XPA-1
Pass Labs XP-10
Herron VTSP-360
PS audio BHK
Backert Rhumba
Would any of the Prima Luna preamps be an option?