I would go with a B&K stereo 202plus, an adcom gfa 555 series 2, or a parasound hca 3500 for your thiels because the thiel speakers need some power to get a full sound out of them and all these amps will do that some more than others but all are quite capable performers.
buget used amp ?
I would like to find a nice budget amp to compliment an Adcom GTP-500ii, the amp will be power Thiel cs 1.6. The Pre Amp and Speakers will not be replaced. Thoughts? Thank you.