Once the switching noise is removed when very low power testing using the
"Audio Precision’s auxiliary AUX-0025 passive low-pass filter, which eliminates noise above 200kHz that might otherwise overload the SYS2722’s input circuitry."You can get either a clean square 10khz square wave, but it's almost indistinguishable if you don't use the AUX-0025, because of the imbedded switching noise, because the amps output noise filter is set very high > 100khz
Or you get a very slewed sick looking 10k square wave with phase shift, but with not much imbedded noise because the units output filter is really working hard down low <100khz.
What ever you do, neither is right.
The only right is as Technics did move the switching frequency up 3 x higher to 1.5mhz and then so also the switching noise filter, then it can do it’s job properly and not effect the audio band with phase shift from 20khz down.