@stevecham
Yes, .02% at 1 watt is completely insane when it's all high order garbage like class D makes. Go look at the measurements. It's a very different story when .02% is this pretty, negative phase, entirely second order waveform. The human ear doesn't perceive that as distortion or dynamics like it does with high, odd order distortion. It tends to perceive it as depth. It's not technically difficult to build an amp that gets .001% distortion across the power band. It's generally thought those amps sound cold and analytical. The things that really define the character of an amp are the response curves of the gain devices and the character of the distortion they produce when driving a load. Folks aren't going nuts about triodes for their efficiency, gain, and low distortion. People love those things for their distortion and that awesome depth and spaciousness you only get from triodes and single ended JFET amps, and you only get that with that sexy, negative phase, low even order distortion.