As a point of Thiel history, Jim used very good amps to design the speakers. His attitude was that making a good amp was the ampmakers’ business, and making a good speaker was his business. We generally had on hand the best from Levinson, Krell, Audio Research and others for comparison. His workhorse for the 3.7 development was the Krell FPB-600.
But at shows, Thiel usually exhibited with amps priced commensurate with its products. No $30K amp for a $10K speaker. Bryston was often used. I found the Bryston amps rather coarse compared to the better stuff at the factory. Many reports said that all changed with Bryston’s ’cubed’ series - which are more refined. Thiel used the a cubed series amp (perhaps 4B3?) to introduce and show the 3.7. That was the combination that George Cardas dubbed the best sound he had ever heard at a show. Bryston offers trade in and upgrade packages. I suggest that the ’cubed’ Brystons come very close to supporting Jim’s design intent for the 3.7, even though it doesn't meet the double-down standards for full current delivery into low impedance loads.
But at shows, Thiel usually exhibited with amps priced commensurate with its products. No $30K amp for a $10K speaker. Bryston was often used. I found the Bryston amps rather coarse compared to the better stuff at the factory. Many reports said that all changed with Bryston’s ’cubed’ series - which are more refined. Thiel used the a cubed series amp (perhaps 4B3?) to introduce and show the 3.7. That was the combination that George Cardas dubbed the best sound he had ever heard at a show. Bryston offers trade in and upgrade packages. I suggest that the ’cubed’ Brystons come very close to supporting Jim’s design intent for the 3.7, even though it doesn't meet the double-down standards for full current delivery into low impedance loads.