[grsimmon]

I'm familiar with the efficiency of ICE amps such as Bel Canto,  Rowland,  etc.   I'm wondering (generally speaking) how do tubed amps and solid state amps compare to ICE and each other with regard to efficiency? 

[JimJ]

Poorly, but in a home, I wouldn't be worried too much about efficiency unless you're running multiple kW amplifiers for subwoofers.

Class A/B has a theoretical maximum of around 78%, but driving low impedance loads can significantly reduce it. SE tube amps in Class A are well below that.

[Rasta]

You can tell by the amount of heat, light and other by products given off by the unit.  So generally, the more heat given off. the less efficient the device.