Best electronics for Thiel CS3.6 ?

Two key elements must be present: 1)high current capability in the output stage to avoid midbass sluggishness (big torroids and large banks of capacitance) and 2) Tubes in the input stage or the preamp to bring out the soundstaging and liquidity that the CS 3.6 is capable of. Of course you know to keep them at least 3 feet from back and side walls and use sound anchors or points. I am currently using a LLano 200 amp which uses tubes in the input and has two 1.25kva torroids with hexfets in the output stage with excellent results.

Most powerfull Pass X series you can afford?

Think about a BAT tube preamp and VK-500 amp, it's in your price range and I'm guessing it would be a great match although I haven't heard this particular combo.

Outstanding amplifier and preamp from BVaudio P1 and PA300, the excellent combination and the best value for the money unless you want to pay a "name" for $5,000. This is the ultimate configuration I have ever heard, compared to Krell, Gamut, Pass, you name it. Bryston 4BST is excellent amplifier way above the other amps there , I was using it for 3 1/2 years , but I have to say that BVaudio is soudwise above that.

A question a little off the topic but .... I have a 12 year old pair of thiel scs's - smaller bookshelf style speaker, but have never heard another pair of speakers by thiel. Are all thiel's prone to brightness and hard to drive? Any information out there about my speakers? Thanks