Discussion about the Korg PolySix synthesizer

A complete shot in the dark here:

When watching the video it appeared to me as if the problem was not audible
for some patches (around 1:30 for example).

This of course would hint at a different problem, possibly with the voice
board or the effects board.

The "noise" frequency is dependent on the last (or highest? lowest?)
pressed key but will always jump back to the same frequency after the last
key is released. The frequency change seems to be inverted - higher key
presses result in a lower frequency.

In the video I don't really hear a pattern.