Discussion about the Korg PolySix synthesizer

im still fooling with my '367-fixed' polysix and it seems that when i 
play multiple notes simultaneously, the background hiss/white noise 
increases as if it is amplified with each sucessive added voice as 
notes are added to a chord  . some sounds hide it, but its noticeable 
on many patches.  I know i have this noisy pulsing VCA on the MG 
section that i posted about before, and was told to check out around IC 
20/21 on the 387.  While this other white noise doesnt pulse , it is 
similar in tonal quality . The results of this is that the polysix just 
sounds 'dirty', and seems not right. could they be related?