The Lighting Controller

I don't want to make a new scene if possible. We are running the lights live thru the editor and just want to turn them all off for a few minutes then back on at their current levels.

Is there a button that will turn all the lights off at once? I have some LED lights with a single dimmer and 2 4 channel dimmer packs but when I use a group it only controls one of the channels on the dimmer pack. How in the editor am I able to do this live? I dont want a scene setup cause we aren't ...