Awful whirring sound

Can anyone please help?

I’m running Cubase 7 and when I create a new audio track and tell it to use the mono bus a loud whirring noise starts. It doesn’t affect any tracks I’ve already recorded just anything new.

Thanks in advance

What specific audio interface or soundcard are you using to record and playback audio on your computer?

What specific operating system and version are you running on your computer?

Also please make sure you have the latest Cubase 7.0.7 (you didn’t specify 7.5) update installed from the following public downloads page:

http://www.steinberg.net/index.php?id=downloads_cubase_7&L=1