trickydude - I’ll elaborate a little on Harry’s recommendation. I have and use and concur with him on that Adcom amp. But my experience with it taught me a few things. The original Adcom GFA555 was designed by Nelson Pass, as were many of Adcom’s amps. The MkII was not - it shared a chassis, but was otherwise a French design with somewhat different characteristics, far higher parts count and circuit complexity. (Reviewers and many users like the MkII better.)
Enter another twist of vintage gear - upgrading. There are folks who upgrade select vintage amps for better performance than was possible when that piece was new. One such upgrader is Jim Williams of Audio Upgrades in California, who concentrates on pro gear - rebuilding recording consoles, etc. Great work at very reasonable prices. JW offers an upgrade to Nelson’s original GFA555 which he considers a superior design to the MkII. I suggest that an original GFA555 might be found for very short money and my experience says that a JW AUDIO UPGRADE for it will produce stellar amplification for your Thiels. (Note: I’d love to trade my MkII for an original NP so I could do what I am suggesting.)
Note that Nelson and Jim were peers and each used the other’s products from the 1970s onward.