Footnote 2: While I was preparing this review, Jürgen Reis e-mailed me to let me know that the specifications in the Corona C15's manual were based on initial production, and that two things have since been changed: "We improved the power transformer behavior to have a better common- and differential-mode suppression against the mains (which improves the sound), but that reduces the power output a tiny bit from 500W into 4 ohms to 480W. We also made the current protection a bit safer and reduced the maximum output current (depending [on] the time width of the impulses) from 36A to 28A. This reduced the steady-state output power into 2 ohms, but not for impulses shorter than about 100ms."