getting background noise on my mic from my powersource

Hello,
I have a Sony Vaio PCG - FR315M and a Logitech Messenger webcam that connects through my usb. Thing is, i'm getting loads of background buzz on the mic and it seems to be mostly coming from the laptops power source as it 90% vanishes when I take the plug out.
Any ideas on how I can fix this?
Cheers
wacky

 

know what you mean,buzzing from the AC is still a real problem that hasnt been overcome fully even in some modern tech,I can only think of a few things to try,if you have a line in use that instead of the mic input,go into mic properties and turn off microphone boost if its enabled then crank up the mic volume,other than that only a higher quality AC adapter might fix it, a pretty expensive route though

 

cheers for that mate. unfortunatley, i use the mic that is built into the webcam and connected through the usb.
would a better cam have somesort of built in filter for this buzz? the noise is still slightly apparent even when running off battery.
any ideas?