The slew rate states the voltage increase the amp is capable of in one microsecond. This is important for very dynamic recordings (classical music has the greatest dynamics)and becomes more important the more inefficient the connected speakers are.
It is in no way related to an amplifiers bandwidth.
I've seen amps with a bandwidth of 10Hz-35kHz and a slew rate of 45V/microsec and amps that do 1Hz-175kHz and a slew rate of 23V/microsec.
Wattage can be increased by either increasing the voltage capability OR the current capability OR ideally both! The defining part for this in an amp is the powersupply, unfortunately this is also the most expensive part of any amp. The best indicator for a good powersupply is how close the 4ohm output is to the mathematical ideal of twice the 8ohm output.
I know of only one amp that achieves this: the asr emitter. It actually goes one step further and is capable of quadrupling the output into 2ohm.
For something cheaper try QUAD amps, they are designed to run electrostats.
It is in no way related to an amplifiers bandwidth.
I've seen amps with a bandwidth of 10Hz-35kHz and a slew rate of 45V/microsec and amps that do 1Hz-175kHz and a slew rate of 23V/microsec.
Wattage can be increased by either increasing the voltage capability OR the current capability OR ideally both! The defining part for this in an amp is the powersupply, unfortunately this is also the most expensive part of any amp. The best indicator for a good powersupply is how close the 4ohm output is to the mathematical ideal of twice the 8ohm output.
I know of only one amp that achieves this: the asr emitter. It actually goes one step further and is capable of quadrupling the output into 2ohm.
For something cheaper try QUAD amps, they are designed to run electrostats.