Best amp choice for Thiel 2.4

Knowing most the manufactures on your list - meaning I have experience listening to them, except the Ayre I'd lean to the Pass X250.5. My Aerial are probably no harder to drive than your Thiel's and I use a X250. The X250 will have plenty of juice unless you're playing crazy levels which eventually you'll cook your ears and it might not matter later. I wouldn't consider a 300 series ML unless you know it's been recapped and there's proof of it; hardly worth recapping these amps because of the cost doing being so high. With a X1 I'm not sure you're going to hear as much of a difference between an X250 or X350 vs the .5 series but you might. If you had a X10 or up I'd say for sure the .5 series. The .5 series is definitely better, but that being said you might look at a X350 if you really need the power over a X250.5 if you're watching the budget. Before I would spend the difference I'd maybe upgrade to the X10 as well... just a thought. The X1 is a nice preamp so don't get me wrong... just saying if you're leaning towards a pass don't rule out a X250 or X350 and don't sweat the .5 series because the older models are still very good amps. Best of 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.