Hello
Total newbie on modular synthesis here.
I’m trying to use the Liquid Filter module, and have no idea how to control the Envelope Amount. On the VCV VCF module there’s a small knob called Cutoff Frequency CV, but can’t find it on the Liquid Filter. Is there please any workaround ?
I use the VCV VCA to modulate the CV going to the Cutoff Frequency on the Liquid Filter. In general, when you need to modulate a CV signal, running it through a VCA is going to be the best solution.
that works like a charm, thank you ! 
Yuo can also use the FM input 
If you don’t already use it for something else.