It's been mentioned sporadically from what I've searched but is this a problem for most owners thus far? Reason being is I'd like to get an exchange before time runs out if it isn't. When charging through usb (red light comes on), I'll get random crackling, static, sometimes a faint hum in the background. Sometimes a little hiss, as soon as the usb cable is unplugged it's back to normal in an instant. I have not experienced any interference or problems at all as long as it's not charging while turned on, and can use it for hours. Cans: ATH-AD900 Source: Realtek ALC889A This has been tried at mutliple volume levels including the lowest volume on the amp.