What tube pre-amps pair well with Pass amps?

Billtro

What’s the budget? New or used? 

I use use a PS Audio’s BHK Signature preamp with a pair of Telefunken 12au7’s from the early 1960’s into a Pass Labs xa30.8 class a stereo amp and it sounds amazing. Hope this helps.

Scot

Check out the KR P-135.  Has XLR ins and outs.  Review at positive feedback is glowing.  
Full disclosure I am a KR dealer but I think it would be a cool match.  

Scothurwitz

Thanks for the reply.  I'm currently running Prima Luna Dialogue pre-amp and 2 HP amps as mono blocks, which I intend to keep (read tube rolling fun) in a 430 square foot room.  The PS audio pre-amp has been on the screen, as I have their DMP and DAC.  With this matchup, do you think the Pass Labs XA 30.8 has sufficient power for the Sopra 2's?  I've always been intrigued by Class A amps and its on my bucket list. 

One last thing, do class A's handle sub-woofers? 

Thanks for the lead VERDANTAUDIO.  German company?  Its a big world out there.

The most helpful information you could provide would be what sound qualities you value and/or would like to improve upon.  Without that this is really just a shot in the dark.