Korg Poly800/EX800 Users

Hi,

I just picked up a Korg Poly-800 and noticed that even with all noise 
generator controls set to zero, I still receive a subtle white noise 
playback with each note. Is this a common characteristic of the Poly-
800 or might there be an issue with, say, dirty or misaligned DCOs?

Any ideas or solutions regarding this would be greatly appreciated.

Thank you.