Commentaire officiel
It's possible that the mixer is bad - there shouldn't be a buzzing and it could be that there was a crossed connection causing the buzzing and subsequently distortion in the audio output. If you're within the return window with your retailer, you may try returning it for an exchange, otherwise you'll need to contact Pioneer technical support for further assistance. Unfortunately the turnaround is certainly more than a couple of days, but they would be able to better outline the expected time if that's the case.