I know mine pretty well, and my experience shows a battery has to get pretty low for the volume to decrease significantly. But it also depends on how much output you're trying to get from the unit. I've found that plugging into AC won't really help a unit that contains a battery that still has a reasonably good charge. It sounds like you're getting close to zero, though. In your case I might want to remove the battery and run solely on the adapter, as a temporary test. It'll give you one more useful data point. (Just don't unplug the adapter while the amp's still powered up/volume up . . . or things can get ugly fast, "depending.")ok guys tried replacing the 9v battery and it didnt help the volume is still barely audible tommorrow ill get the dc adapter so well see if that works. is it actually possible that a dc adapter will make my bass louder than a 9v battery. just wondering cause thats what everyone is recommending