"Serge Auckland" wrote in
message

Indeed, and in my previous post of the criteria, it was
stated that THD should be measured at all frequencies
20-20k and refers to all powers and all loads for which
the amplifier was designed.


Measuring THD above 10 KHz can be an exercise in futility, as many upper
harmonics will be lost due to the bandpass of the UUT. It's not uncommon for
power amps to be - 3dB at 50 KHz, for example. Better to use twin-tone
measurement techniques.