I'm finding the following unexpected behavior in Predator v1.5 running on PT (RTAS) as well as v1.6 on Logic (AU): when the modwheel is set to modulate cutoff in the Free Modulation section (in this case, modulation slot #1) and under the conditions described below, the filter takes on a bit of a "wah" effect as though it were being modulated with an envelope with a slightly slow attack. This occurs even when there's no envelope-->cutoff modulation. However, when CC#1 is assigned directly to the cutoff control, this "wah" effect doesn't occur.
STEPS to REPRODUCE
1) start with a completely zero'd patch with no modulations of any kind save for Amp envelope set to "gate" (zero attack, full sustain, zero release). Enable one oscillator, sawtooth, no spread. ECS cleared. Filter response = 12 LP
2) set Cutoff to 410 Hz or thereabouts
3) Free Modulation #1: assign modwheel --> filter frequency, depth zero. Move the modwheel to ensure that no modulations are taking place.
4) now set the Free Mod #1 amount to 50% and move the modwheel slowly up to mid position, playing as you do this. You'll hear a soft "wha" sound as the note attacks.
5) clear Free Mod #1 by setting the source to "none" or setting the modulation amount to zero. Then assign CC#1 to the Cutoff control directly
6) move the modwheel slowly upward as you play and you'll hear that the attack is sharp and clean (as expected) with no "wha"
Wondering if the sound produced in steps 1 - 4 is normal behavior and part of the character of Predator, or if something's not quite right.
I'll be curious to know if you find the same behavior and if a fix is possible. Case in point as to why this is problematic:
On the track I'm currently producing, I have Mod Wheel --> Cutoff (as described above in the Free Mod section) to open and close the filter during a fast 16th note sequence/pattern created with Predator's arpeggiator. The sonic character of the notes gets "mushy" when I open the filter because of the wah effect I described. This didn't happen when I assign the modwheel to the filter directly (the notes' attacks were sharp, perfect, as expected). So that's my workaround for now, but it's not a convenient solution for many reasons, including the fact that I can't set a static value for filter cutoff (as it's always under CC control).