Audioguru, how does the AC adapter magically route power away from the batteries? If I wire the adapter parallel to the batteries, won't some current be routed through the batteries, dangerously? I will remind you that I have not constructed this yet. It is not a prebuilt stereo that automatically switches between batteries and adapter. I need help making a circuit that will switch between batteries and a DC adapter. Or, I suppose, I could just make a manual switch so I can use either. But automatic would be much neater.