Today, I went to turn on the radio in my XK and instead of music I now get a loud buzzing noise. I thought at first it was a blown speaker, but it's not one speaker it seams to be all of them. This car has the HK Premium audio in it. Any thoughts?

 

Is it just the radio, or does it do this with a CD or tape also? If it is just the radio it could be a poor connection somewhere to the antenna. If it does this with the CD and tape also, then it could be something with the amp.

 

Ok, I tried switching to the CD player and running a disk. The issue persisted. How would I go about testing the factory amp?