How to calculate amp's supurious?

[YiPing]

:?:

Harmonics are (usually unwanted) signals which are exact multiples of the operating frequency.
Supurious are other unwanted signals. Amplifiers do not generate signals (other than IMD) unless they are unstable.

 

[xinxin]

Calculation is so impossible for supurious, You could view us from the spectrum when amp operates out of linearity.