Acoustat , Hafler TNT and Jim Strickland

The Accoustat and the Transnova from Hafler are the same design. They are designed to  take advantage of the advantages of Mosfets ability to self stabilize at high temperature. Other amps use the mosfets in topologies designed for earlier bipolar devices. So the transnova can gets most of gain in the final stage, and have less gain stages, only 3 a la Nelson Pass.  Most amps have 5 or so gain stages, the Transnova has 3. This also allows the input state FET to run in class A. FETs have characteristic gain similar to tube amps. This allows the amp to be very stable into terrible loads like one or two ohms which would send other amps up in smoke. It's a patented design. The other amps which are very stable into difficult loads are the new digital amps, or the NAD soft clipping amps   I use this amp to drive Quad 989's and have plans to use also for Original Ohm Walsh Driver, notorious for blowing up. I bought an old pair on Craigslist that needs reconeing. The other thing in general is you dont' want to run amps so hard, you get tons of distortion. 35-50% of rated volume keeps most amps and preamps in a very nice low distortion mode, which is what makes them sweet. I keep hearing how you have to have at least 250 watts per channel or bi amp, that's all a load of rubbish, no offense.