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

Pubul57...Thiel has shown its speakers often with Bryston and Simaudio amplification at shows int he last 2-3 years. But again, as Unsound has pointed out, this could be more a function of local dealers, etc...I drive my 2.4s with ARC Ref 110 and love the combination. I am probably leaving a little bit of performance (dynamics and lw end extension) on the table but what I gain in terms of tone/timbre, separation, transparency/resolution, and 3D dimensionality is quite nice. I initially drove the 2.4s with Musical Fidelity's A5 integrated amp (250wpc into 8ohms and 500wpc into 4ohms) but the top end was a bit jarring and resulted in listener fatigue. I also tried out Simaudio P7/W7 (separates) and the i7 (integrated) for about a week each and liked the Simaudio/Thiel combo.

Yes, I was mighty impressed with the ARC VT100, and I assume the Ref 110 would be better yet. ARC seems to also work well with Maggies - so difficult loads and tube amps that do seem to work well. I have never heard the combination, nor heard others comment on it, but it would seem the that the stereotypical sonic flavors of Thiel and MAC (6600 integrated would do) would make for a pretty good combination - detailed neutrality with smoothness, power and autoformers for handling impedance swings. Again, never tried it, but would be curious.

The original owner of my 2.4s used a McIntosh MC-402... which he certainly loved (I think he was still going to use it with a new pair of 3.7s).

Wish folks had had a warmer response to the idea of the Aleph 2s, that would have saved over 1k over the 250.5. You all convinced me, however, that I'd probably end up reselling them sooner than later.

Thanks for the input. Despite being fairly sold on the 250.5, I am open to trying some other brands, so the other suggestions are welcome.

Ohhh, and obviously the low end isn't my primary focus (hence even trying the XA30.5 to start with)... imaging is really the most important target as far as I'm concerned.

Not to suggest that good bass it the number one priority, but IME without good solid bass response the Thiels can sound a bit tipped up. I think the part of the appeal of the Thiels, is due to the outstanding balance of all paramaters, rather than any specific one. FWIW, I wouldn't completely ignore the bass, it can overlap into other areas of appreciation.