Pre-amp suggestions for Thiel 2.4/Pass Labs XA30.5

Cal3713...I would assume a used Pass XP-10 would be a good combination with your XA30.5 (check with folks at Reno Hifi who often have good used/demo inventory and I believe they allow 30-day in-home auditions). Other options to consider:

ARC LS-17: http://www.audiogon.com/cgi-bin/cls.pl?preatube&1328708163&/Audio-Research-LS-17-Tube-Prea. very detailed/resolving but still gives you smooth/continuous flow of music with 3D presentation

CJ Classic SE: http://www.audiogon.com/cgi-bin/cls.pl?preatube&1329081914&/conrad-johnson-Classic-SE-tube. Shoudl give you the CJ golden hue but with updated modern and highly resolved sound. SE version includes Teflon caps which take a very long time to burn in (>600hrs) but should deliver on resolution and spatiality in spades. This looks like a good deal for a brand new unit with full factory warranty.

Good luck.

Cal3713, went back and read the entire thread. I still don't see a direct recommendation from Nelson Pass for the XA30.5 for the Thiel CS 2.4's. The OP does seem to vastly prefer the XA30.5 to the X250.5, but with the caveat of not having to play loud in a large room. The thread also points out that the Thiel Cs 2.4's spend much of their time below 4 Ohms. Aparently others there have had similar conjecture as I had re: output Class bias.
...But enough of that. I think the a Pass pre would be just the ticket. What ever you choose, I'd suggest using a fully balanced pre.

Unsound: Yeah, I've only lived with the amp and speakers for a week or so (both are new to me), so other than some initial impressions of really hearing some great stuff out of the two, I still don't know either in much detail. Perhaps in the end I'll have to decide whether to switch to the 250.5 or change speakers. I certainly was encouraged by the volume level needed to leave class A, so we'll see... And thanks for the rec.

Cal3713, the XA30.5 is quite a bit different than typically rated 30 Watt amplifiers, though I think I would choose a different Pass amp, it could very well work very well for you with your Thiel CS 2.4's.

"some successful preamp pairing suggestions would still be useful."

I see your thread has splintered in many ways. I'm shocked :-).

I have the 30.5 and 100.5's and paired them with Conrad Johnson tube preamps (ART and ACT 2.2). I am very happy with the sound. Of their preamps I'd recommend at least the 16 or 17 or you may find another brand that suits you better. Good luck.