I just purchased a pair of B&W 803Ds over the weekend. Once they were hooked up to my system I listened to a few CDs playing on a Sony CD player. Everything is good, speakers sound wonderful.

I then turned on my Dell laptop which is always hooked up to my 990 via USB cable but didn't start playing any music yet. I walked away from the laptop to another part of the room and I noticed a high pitched tone in the room but couldn't figure out where it was coming from. I finally tracked it down to the tweeter in the 803. I turned off the laptop and the high-pitched tone disappeared. I turned the laptop back on and it appeared again. I then unplugged the USB cable from the laptop and the tone went away?

I never noticed this sound coming from my previous set of speakers (PSB Silveri) that were hooked up to the system.

Why is the USB cable/laptop causing this? Is there a cure?

Mark