Want to give a shout out to Carver, the concept for his magnetic field amplifier continues to be used by Yamaha, NuForce and possibly even NAD (D 3020).
Carver's design used a linear amplifier of relatively small power handling and hooked it up to a power supply of varying rail voltages. This minimized the power dissipation required in the output stage. Carver sued (and won) against Yamaha, but the Yamaha Pro line is using the EEEngine which seems derived. NuForce is using the idea in their hybrid amps, Class-D providing the voltage rails, with a linear amp sandwich, and maybe... the NAD D 3020.
Still, how old is this tech? We can definitely argue against calling it all that revolutionary.
Is any of it better sounding? Not sure, but Yamaha and Nuforce are free to send me samples.... :)
Best,
E