"Can't get the ducking effect to work on the low pass filter setting. Is that by design? If you know, please let me know!" Can you expand on this please? Ducking should working in either LP or HP. The switch just changes the type of filter being used on the sidechain. If you're in LP mode and it's not ducking, do you have the filter turned all the way counter-clockwise? If you do then you'd be filtering out all of the sidechain signal. The same would be true in HP mode with the filter knob turned all the way clockwise.