What tube pre-amps pair well with Pass amps?

SOIX, you are absolutely correct.  I've just relocated and am in the process of addressing my new room's acoustics.  Treatments are on order and until I get the set up I won't really be able to tell where I'm at.  Until then, I'm just searching for possible ideas.  Since my current system is all tubes, I'd like to explore SS with a little more slam for complex and/or dynamic music.  

Thanks for your reply.

I have a Pass XA30.8 paired with a VAC Renaissance MK5 preamp.  Works very well together musically bolstered by design compatibility in impedance, gain, and both having fully differentially balanced circuits.  Drop a pair of NOS 6922 into the VAC and you get the quietness of a Class A SS amp paired with the tubey goodness of the VAC.  A perfect pairing in particular with speakers around 8 ohms and 90dB sensitivity in my experience.

Linear Tube Audio ZOTL Preamp

+1 on the LTA  MZ2 with a XA30.8.  This is a very good pairing and drives my Vandersteen Treo CT’s with finesse and power.