Q: Audio channel with buzzing sound
A: My 6012 has been buzzing through the audio channel for some time after it has reached normal operating temperature, making it impossible to hear the ambient noise. If I reset the audio input level of the camera to 1, the humming noise will be reduced, but the ambient noise will not be noticeable.
It is best to replace the power supply with another IN-6012HD camera and make sure it is not too close to the camera!
If you do not have a suitable replacement power supply, you can also connect another outlet - preferably in another room and directly to the wall socket (no multiple socket) - connect.
Also make sure that you do not wind the power supply cable around the power supply, or place it wound up next to the power supply.