Thanks for the catch Eric. I meant to say the rise time is "very FAST at 8 microsec". Rise time measures how fast the amp goes from 10% of rated power to 90% rated power. It's like accelerating a car. Other amp manufacturers don't usually post that stat so slew rates are more common. I mentioned in the OP that the Bryston has a slew rate of 60V/microsec and the Axiom slew rate is >80V/microsec, while the Outlaw has only 50V/microsec.

John