If things are going well you will not hear 'speed' in an amplifier. If you do seem to recognize such based simply on highs and transient response, IMO/IME that is likely due to a coloration and not anything else (and often caused by trace amounts of higher ordered harmonic distortion).
Real speed is evident if the soundstage is deep and wide but not unnaturally so (this is because with speed comes correct phase response); the amp will be relaxed at high frequencies but obviously able to play them with a black background. I hesitate to say any more as so many other factors are involved/so many variables can exist...
Real speed is evident if the soundstage is deep and wide but not unnaturally so (this is because with speed comes correct phase response); the amp will be relaxed at high frequencies but obviously able to play them with a black background. I hesitate to say any more as so many other factors are involved/so many variables can exist...