Joule Electra VZN-100's put a $30 shelf on my electric bill the month they showed up. I look at it this way, they serve to offset the heating bill for the winter. My basement is never cold and I don't have to turn the heat on down there. I can't use them when it is much past 70 out. I put one of those kill-a-watt things on it, draw was something like 11 amps. I also tried plugging them into powerstrip with my other equipment when diagnosing a ground loop issue. The powerstrip blew almost immediately. They do draw the power.
And remember, if you are making heat with your amp while cooling your house with AC, every penny in electricity that your amp uses will cost you another penny on the AC bill*the inefficiency of your AC.
And remember, if you are making heat with your amp while cooling your house with AC, every penny in electricity that your amp uses will cost you another penny on the AC bill*the inefficiency of your AC.