I have been experiencing this issue since ever but never knew how to fix it. When my TV is connected to external speakers, there is a slight buzzing noise from the speakers. It increases when the volume in the TV or the ext. speakers is increased.
The same case when a guitar is connected to the speaker. I thought it could an issue with the jacks or the wires and changed them, but it persists.
What causes this noise actually. Is the reason same for both the above cases. Can this be fixed