PaulParanoia

Hi All, I just got one of these CT-S300 Keyboards. I'm liking it but there's a humming noise coming from both the speakers and the headphones. It sounds a bit like a laptop fan running at low speed. There's also a quieter high pitched buzz coming from the right speaker. I realise this is a cheap keyboard so some low level hum may be acceptable. However I can hear this noise clearly from a meter or so away. Does anyone else who owns this keyboard have the same issue or do I have a defective unit? Thanks.