I have had this PSW 404 since 11/27. I noticed that the red standby light is always on whether the switch is in the "Auto" or "Off" position. In the "On" position the light goes green or when it is getting a signal in the "Auto" position. There is also a very low level (not very loud) hum that does not change regardless of position of the switch or volume setting. It only goes away when I pull the plug. Sounds to me like I have a defective unit. What do you think?