Slew rate and frequency response are both important because one addresses transient response and the other addresses steady-state response. No slew-rate spec is going to tell you what the amp will sound like. There are several reasons:
1) Transient response can vary as a function of frequency, and usually does - this is controlled by the power delivery topology of the amplifier
2) Fast slew-rates can be underdamped or overdamped, and if you are lucky, critically damped. This means that the transient overshoots when the amp is underdamped causing a higher voltage than that in the original waveform. If the amp is underdamped, then the transient does not reach the voltage that is in the recording.
There is no commonly practiced spec that captures the above phenomena.
Steve N.
Manufacturer
Empirical Audio
1) Transient response can vary as a function of frequency, and usually does - this is controlled by the power delivery topology of the amplifier
2) Fast slew-rates can be underdamped or overdamped, and if you are lucky, critically damped. This means that the transient overshoots when the amp is underdamped causing a higher voltage than that in the original waveform. If the amp is underdamped, then the transient does not reach the voltage that is in the recording.
There is no commonly practiced spec that captures the above phenomena.
Steve N.
Manufacturer
Empirical Audio