I hear a buzz noise as my stereo changes from song to song, and anytime a function is pressed on the remote. it is faint, but annoying none the less. I have tested this by both my speakers, and headphones, I have unhooked my amplified fm antenna as well.
I just bought the unit, so I have no idea how long this has  been happening.

Panama 

How old is the unit ?

This unit was made it 1997. Just a note the buzz is best heard with head phones one, and only happens when the cd is switching from song to song either on its own or using the remote.