Class "A" amps draw the most current at idle, and draw less when playing music. So you are saving money by playing music if it is on.
Most amps, even the ones called class "A" are not 100% class "A" and when they get beyond the class "A" into class B they may draw more current than at idle. The big names which are way into class "A" usually do not ever get to class B operation, unless driven really hard.
Most amps, even the ones called class "A" are not 100% class "A" and when they get beyond the class "A" into class B they may draw more current than at idle. The big names which are way into class "A" usually do not ever get to class B operation, unless driven really hard.