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

I have had great luck pairing the Musical Fidelity kW preamp with Nelson Pass's First Watt amps. There is one for sale used now I believe. You will be hard pressed to find a better preamp for the money. Check out the Stereophile review (and the review's measurements), and other reviews on the unit. A tank, with a massive power supply. Truly the game changer in my system.

Thanks for all the comments folks... it's been useful, even if somewhat discursive. I've been leaning towards Aesthetix Calypso, mostly because it is fully balanced and has especially high gain, although I see that the Stereophile measurements have its output impedance ranges from 112 ohms at 1kHz to 3900 ohms at 20Hz (balanced). Perhaps that's on the edge of being a problem with the Pass' input impedance?

So far, the other contender I've been considering is the Audio Research LS-17. Most of the other suggestions got axed because they are unbalanced, higher than my price cap, or (in a couple cases) don't come with a remote.

Unfortunately I still need to sell my old system to free up funds for any purchase, so if anyone's interested in Thiel 1.6s, a Classe CAP-151, or an Exemplar Universal player... just let me know. They'll probably be posted next month, hopefully once folks have started to recover from the holidays.

Thanks again for all the input.

Are you limiting your considerations to tube pres?

Cal3713...the output impedance of the Aesthetix Calypso may present a problem in the treble region given the high impedance at 20KHz (3900 ohms vs. 30Kohms input impedance for your Pass amp via balanced, < 1:10 ratio). On paper, this suggests potential attenuation (or think of it as a roll-off) in high frequencies, so this may make the overall tonal balance more shifted towards the midrange and bass. If you are set on that option, I would highly recommend trying it in your rig before purchasing if you can.

You should check the ARC LS-17 for measurements as well. If you cannot find output impedance curve, I would call ARC and ask them. Let them know what amp you have so that they can advise you on whether the LS-17 would be agood match from an impedance perspective.

Good luck.

Unsound, not I'm not, I guess I just saw in some other threads that people had used those with Pass Amps and had success... and they were recommended in here. And, perhaps it was just made it an easier choice to be biased towards either tubes or SS. You'd personally choose a solid-state? I did see that there's a Pass X1 up for about $1900.