Intermittent radio buzzing problem, please help!

[Tranlm]

Hey guys,

Please help me. I have a 1998 boxster with a CDR-210 radio unit. For some reason lately, the radio has been intermittently buzzing (or whistling depending on how you describe it) when I start my car. This buzzing noise increases as I accelerate. If I turn the radio off, the sound goes away. Once my car warms up though and I'm cruising on the highway, I turn the radio back on and the buzz is gone.

I've been trying to figure out what it is and think it might be the factory amp. I'm not sure. Has anyone else had this problem?

Thanks in advance!