Yeah, I know I'm late to the party on this. And I have spent a little time playing with the power switch set ti Variac up to this point. I just finally took the time to pay attention to the differences between the standard power on and Variac settings. The change in response is more significant than it sounds / feels at first. Both are very useful and sound great! Full voltage feels immediate, urgent in response. Variac is a bit more relaxed and forgiving and changes the texture of the attack. I'll be playing around with this more over the next week or so. As others have suggested to me Variac is especially cool in the Channel 2, Crunch mode!