Audio Research DSi200 earned an Energy Star rating from the government! When the DSi200 was introduced in 2009 we called it our “solid-state hybrid” design because it combined a massive, highly regulated, linear analog power supply with a “green” discrete analog switching-MOSFET output stage for highly efficient power conversion and low power consumption. People mistakenly called it a digital amp, but it was all analog and fully balanced from input to output.
The analog power supply and all-discrete MOSFET output stage were complete Audio Research designs and did not rely on prepackaged modules or other OEM solutions common to other manufacturers.
It was the first of the “Definition Series”, with three more amplifiers to follow. The DSi200 idled at 38 watts, so it could be left on without heating an enclosed cabinet. And it sounded much better when left on continuously. It was also the first Audio Research product to use silver handles, and a silver chassis.
The Class-T 150M, a modular multichannel amplifier (1-7 channels), introduced in 2002, is a story for another day.