Looking forward to hearing more about the new First Watt amp, I copied below what I could find on the web. In the video clip they mention it runs hot, so the stereo version is limited to 10 watts, and that Nelson is planning a monoblock version for higher power.
First Watt SIT-4 power amplifier The SIT-4 is a2 channel power amplifier using the industrial Static lnduction Transistors, succeeding the SIT-1 ,2, and 3 but following their technical philosophy and construction. SlTs are ideal for high quality audio performance with very simple single-ended Class A circuits with little or no active circuit elements or negative feedback. Their character is like a Triode tube, but at the voltages and currents that can easily drive loudspeakers directly. ln the earlier amplifiers we used a SemiSouth custom Silicon Carbide device rated at 50 watts. This next generation is equipped with Tokin SlTs rated at 400 watts and 30 amps and a bandwidth extending to 50 MegaHertz.