The Theil's need an amp with current, solid state that can "almost" keep doubling it's wattage to 2ohms
EG:
8ohms-100w
4ohms-200w
2ohms-400w
This means a solid state amp that uses BJT (bi-polar) output transistors, Tube, Mosfet, and Class D need not apply. See impedance v -phase angle graph.
http://www.stereophile.com/images/archivesart/1208T37fig1.jpg
Cheers George
EG:
8ohms-100w
4ohms-200w
2ohms-400w
This means a solid state amp that uses BJT (bi-polar) output transistors, Tube, Mosfet, and Class D need not apply. See impedance v -phase angle graph.
http://www.stereophile.com/images/archivesart/1208T37fig1.jpg
Quote from Stereophile's measurements
The sensitivity is usefully higher than average, which is a good thing considering that the CS3.7's impedance remains between 2 and 3 ohms over much of the audioband (fig.1), and that there is a demanding combination of 3.8 ohms and –40° capacitive phase angle at 60Hz. Thiel specifies the impedance being nominally 4 ohms, with a minimum of 2.8 ohms. I actually found the minimum impedance to be 2.4 ohms at 125Hz.
The difference between 2.8 and 2.4 ohms is academic, either mandating use of an amplifier that has no problem delivering high currents.
Cheers George