I don't know if this is exspected. If not, then it's a bug.
When in DUO Noise Mode the FEET 1 have an impact on the Noise while FEET 2 have no impact.
I would exspect Either none had impact or the FEET 1 had impact on the Noise in the first Synth Line, and FEET 2 had impact on the Noise on the second Synth Line.
I think it's strange it's not the same.
Try this:
1. Select New/ Default preset.
2. Turn of the Waveforms for both Synth Lines.
3. Turn the Noise full up for both Synth Lines.
4. Set the Global MIX I-II to Center position by double click.
5. Set Global BRILL to max upper postion to reduce filter cutoff.
6. Set Channels PAN to MAX up or down position.
7. Play a note.
8. Change FEET for Synth Line 1. The sound change for both Synth Lines Noises.
9. Change FEET for Synth Line 2. The sound does'nt change the same. So there is a difference. Why?
In Single Noise Mode none of the FEET parameters have an impact on the Noise, what's exspected.
But i like the FEET have an impact.
