I own a Hikvision DS-2DE4225IW-DE PTZ camera. I decided to connect an external microphone to it and noticed electric noise/humming coming through it. At first I thought that it was my faulty wiring of the microphone. However, I've also noticed that there is no noise during the booting process (when my camera checks all it's PTZ and focus functions and then drops a "Check camera success" message on the screen). The noise starts right after the booting is complete which makes me think that the problem is originating from inside the camera. First example: (you can hear it loud and clear at 00:06) Second example: (a little bit drowned in the noise of the sea, but I marked the moment where the humming starts, around 00:04) The microphone is powered through the same 12v that feeds the camera. Any ideas?