Best possible separates for Thiel CS 3.7

They're a difficult load, I wouldn't put tubes on them. For amps I'd look at Bryston 28B Cubed, Pass X350.8/X260.8, MOON 870A, Audia Flight Strumento 4, Accustic Arts AMPIII, BAT  VK-655SE, warmer and smoother SS in general.

For the remaining budget I'd pick a DAC that could drive the amps directly if you only listen to digital.

A no preamp configuration that would be top notch is Ayre MX-R Twenty driven by Totaldac Seven + d1-server.

A no preamp configuration

FWIW, Stereophile’s review of the Ayre QX-5 found the SQ to be better with a KX-5 feeding the amp rather than using the DAC’s digital volume control in a direct connection. That may not apply to the totaldac but you want to get it right when spending this much!

@beetlemania You can check this video where Vincent Brient drives directly 3 huge monoblocks with his 4 units Totaldac Twelve at the Munich show :
https://www.youtube.com/watch?v=2VxI3BVKiDI

Hi guys, here's the latest news regarding my quest for the ultimate Thiel CS 3.7 rig.On oct 24 i will be demoeing in Geneva at Dartzeel factory NHB-18NS + NHB-108 model 2 combo.The next day i will be in Zurich to demo Aries Cerat Impera ll preamp + Diana Forte stereo amp driving a pair of Thiel CS 3.7s.The AC Kassandra Ref DAC will also be in this rig.In the afternoon we will go listen 2 other rigs also with Aries Cerat pre-power and some KR Audio stereo amp driving nice horns.There is one last ultimate pre-power combo that i would like to demo on my Thiels : CH Precision L1+X1+M1 stereo.As you can see my budget has raised quite a bit but this will be for me a once in a life time system.My digital front end will be the brand new Totaldac d1-Twelve mk2 + d1-server.