Pretty sure you'd need to install their drivers for testing on the windows side.
Bit of a pain, I know, but it's a pretty big troubleshooting step.
If, for example, you experience the same thing on the desktop PC, you've pretty much narrowed the issue down to mic, cable, or something environmental.
Hey Steen, installed the drivers and tried it on my PC. zero buzz. any idea where to go from here? would really like to be using my macbook over my parents computer