We are Mac dealers - so let me prefix this resopnse with that statement.
Definitely do not drive the Thiel's with anything less than a MC-352. For two reasons - one power rating, and two autoformers. The MC-352 is the smallest amp Mac makes with autoformers, and they really help on speakers with erratic impedance such as the Thiel's. The autoformers effectively add impedance to the circuit which makes the speakers easier to drive and less onerous on the amplifier in terms of current demands, even when the speaker's impedance dips. Also you need raw horsepower to drive those speakers, particularly current. The higher up you go on the chain of Mac amps, the better off you will be sonically. The MC-352 is a great sounding amp and a very capable one at that. But frankly with your Thiel's you could enjoy better sound by moving up to the 652. You don't _need_ to, but it would be worth auditioning. I think you would find the improvement over the 352 significant.
Definitely do not drive the Thiel's with anything less than a MC-352. For two reasons - one power rating, and two autoformers. The MC-352 is the smallest amp Mac makes with autoformers, and they really help on speakers with erratic impedance such as the Thiel's. The autoformers effectively add impedance to the circuit which makes the speakers easier to drive and less onerous on the amplifier in terms of current demands, even when the speaker's impedance dips. Also you need raw horsepower to drive those speakers, particularly current. The higher up you go on the chain of Mac amps, the better off you will be sonically. The MC-352 is a great sounding amp and a very capable one at that. But frankly with your Thiel's you could enjoy better sound by moving up to the 652. You don't _need_ to, but it would be worth auditioning. I think you would find the improvement over the 352 significant.