When does a dup sound comes out of a pa speaker

[abdielsam]

why does a dup sound comes through the pa speaker ,when the amp is switched on......

 

[Guest]

I suspect it's usually the power supply. Many amplifiers use a timed electromechanical relay switch that isolates the speakers until the power supply has settled down.

 

[abdielsam]

Best answer selected by abdielsam.