Best amp choice for Thiel 2.4

Thiels are a lot different than Aerials, IMHO.  I've owned both Thiels and Aerials.  They're more towards opposite ends of the spectrum in fact.  The Pass will be lean with the Thiels, especially with a Pass preamp.  I can see how it would sound great with the Aerials.  You want a tube preamp if your going to get the best out of the Thiels.  Even Kathy Gornick, formally of Thiel, said she never heard a Thiel speaker that didn't sound better with a tube preamp.

BAT, Belles, CJ and Ayre would be my choices  for Thiel if going with newer amps.  The old ML and certain Krells were great, but as stated, recapping may be an issue.  Good luck.

Definitely agree Thiel and Aerial’s are totally different and I would agree as well to use a tube preamp with a Pass amp on Thiel’s, but not to tame the Pass. I use a tube preamp on my Pass, but I wouldn’t consider my preamp to have a fat tube sound. Only mentioned Aerial’s as they require power and a X250 will drive the Thiels just fine. If Curio is by chance leaning to Pass, a X250 should be enough juice so why spend more for a X350. If money is no issue then why not I suppose, but then I’d go X250.5 or look at the XA series. I question the a X1 will really show how great the .5 series is though, or the X250.5 might bring out something in the X1. I remember many years ago listening to a pair of Thiel 2’s (don’t recall what version) through an ARC LS3 at the time; and although I believed the LS3 to be a very, very good SS preamp in its day, it did not work on the Thiel’s. Maybe I haven’t heard enough Pass gear but I don’t find their amps to be lean at all, but have heard a few Krell’s and other big dog SS amps from many that didn’t do it for me. No Pass amp is going to fool a tube amp user it’s a tube amp, but they get it close for the money, and closer than most.

I strongly agree with Carmenc on a tube preamp. I might have looked at a nice tube preamp first before picking up the X1. I personally will always take a tube preamp over a SS unit, but can go either way on tube or SS amps such as a Pass. I choose not to go with tube amps as they are a pain in the butt to run over the long haul and cost of re-tubing and heat especially on a big tube amps. Had a couple tube amps over the years and I appreciate what they do, but not for me at this point in time.

Sounds like Mark at Reno HiFi is easy to work with and the most you’ll be out is shipping if you don’t like a Pass amp... that’s if you return it. Maybe Ayre and others will directly or one of their dealers do the same so you can try one out at home first. ModWright KWA 150 SE might be another amp to read up on as well, and Dan is a great guy and will be honest with you on how he thinks his amp will work with your system. Good luck.

I haven't found the Pass X series amps to be lean at all with Thiels, if anything ever so slightly on the other side of neutral, and a very lovely match indeed. As for the power levels, so much of that depends on the specific Thiels under consideration and the room, but all else being equal and as budget permits I would almost always suggest more rather than less power with Thiels. Tube's or ss pres work just fine with Thiels. Whether or not a tube pre is appropriate might have more to do with the partnering amplifier. It's more likely to find ss pres with the impedance and balanced outputs that the Pass Labs amps prefer.