Now it is possible to control the resonance which is only switchable on the main module and with the expander you can use the internal VCA finally to create a VCO-VCF-VCA voice.
Filter: The Resonance potentiometer allows for setting the filter resonance manually.
If a CV is plugged to the resonance CV input, this control turns into it's attenuator.
There's also a scalable CV input for modulating the cutoff frequency.
VCO: An exponential FM input with attenuator. It is an addition to the VCO's lineaar and Thru-Zero inputs.
VCA: full fledged VCA including an input with level control, an output and a CV input with attenuator.