Background Noise/Humming solution? UR22C

I recently purchased the UR22C to plug my guitar into GarageBand. I have downloaded and installed the driver and elicenser, however when I run the interface through GarageBand there is a very distinct buzzing sound. I cannot seem to find a way to stop the humming sound. If someone has any advice, it is greatly appreciated!

Obviously step one is connecting the USB cable to your Mac. (Note: for best results plug them directly into your Mac; not into a USB hub.) After that, open GarageBand and go to Preferences and click on the Audio/Midi tab.