Devialet's power transformer
The Devialet D-Premier directly converts the wall current to DC, then uses a high-efficiency switch-mode power supply running at a very high frequency to power the audio circuitry. I asked Matthias Moronvalle if this meant that the power transformer could be much smaller than usual? His response was to show me the two small wafers sitting on his laptop. "That's the transformer," he told me, "with a continuous rating of 600VA." Ulp!