Not every power switch on amplifiers kills all the current. Some will just go into standby mode. Jeff rowland comes to mind.
Homemade amp switcher
I made a switch box that sequences all my amps for my hometheater.I use seven in all.Three for the surround and four for my subs.While at a store this weekend the sales guy told me that it's like pulling the plug out of the wall and putting it back in everytime I turn on and off.Is it no different than the switch on the front of the amp itself.I have used this device for about a year without fault.It uses the 12vdc trigger from my processor.Thanx for your input on this.