Slew rate and risetime are related terms that refer to how quickly the amp can change states to follow the input voltage to output voltage. Think of "acceleration." This can be a good indicator of how "quick" an amplifier sounds: getting the leading edges of transients accurately reproduced, for example. It also impacts resolution and detail.
A corrolary to slew rate is "settling time" and this is just as important to how resolving the amplifier can be. As the name suggests, settling time reflects how quickly an amplifier can return to its nominal state after passing a large voltage swing. Bumps in settling time will be reflected in the trailing edges of transients and can show up as ringing and added sibilance.
Spectral and Atma-Sphere are two other manufactures that publish a slew rate for their amplifiers. Atma-Sphere quotes this as "risetime" (using the same 600 volts/microsecond measure as Spectral), whereas Spectral makes a distinction between risetime and slew rate.
http://www.atma-sphere.com/products/ma2.html
http://www.spectralaudio.com/dma360_spec.htm
However, like any other measurement it's not worth reading too much into it because it's only one aspect of an amplifier's performance envelope and there are so many aspects of sound quality that we certainly differentiate in listening but don't know how to measure.
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A corrolary to slew rate is "settling time" and this is just as important to how resolving the amplifier can be. As the name suggests, settling time reflects how quickly an amplifier can return to its nominal state after passing a large voltage swing. Bumps in settling time will be reflected in the trailing edges of transients and can show up as ringing and added sibilance.
Spectral and Atma-Sphere are two other manufactures that publish a slew rate for their amplifiers. Atma-Sphere quotes this as "risetime" (using the same 600 volts/microsecond measure as Spectral), whereas Spectral makes a distinction between risetime and slew rate.
http://www.atma-sphere.com/products/ma2.html
http://www.spectralaudio.com/dma360_spec.htm
However, like any other measurement it's not worth reading too much into it because it's only one aspect of an amplifier's performance envelope and there are so many aspects of sound quality that we certainly differentiate in listening but don't know how to measure.
.