I have an mp3 player in my car and i think it is having a ground loop issue. Whenever I plug it into my cig. lighter, I could hear a whining noise. The whining noise's pitch is proportional to the engine's RPM. I'm trying to fix and understand the problem because my background is electrical http://img11.imageshack.us/img11/2213/drawing1tc.jpg [Broken] The picture above is a model of the the mp3 player and the ground loop. Is the model above accurate? Would the audio from the headphone have a whining noise that originates from the car's alternator? From my understand, the ground loop is caused by noise current flowing through Rground. Since the audio generator references the node @ Rground, the audio source picks up the noise and outputs it to the headphones.