Discussion about the Korg PolySix synthesizer

Hi group, 
     My Polysix is producing an odd effect across the entire board. 
It seems to be independent of any setting or effect, and is present when just using a simple saw wave. The sound is a kind of garble/grainy texture that becomes much more present once the cutoff goes below a certain point. It makes for a very dirty undesirable bass sound. Otherwise everything is working great. I am not a DIY guy so anything more than a connection issue and I will have to turn it over to a tech. While I'm asking, if anyone knows a good synth tech in the Philadelphia area, I may be in need. ha. Thanks in advance for any guidance.

Zack