2- THE FILTER (VCF / Voltage Control Filter) :
As the name suggests, this module allows you to filter the sound by removing certain frequencies from the incoming sound.
FREQUENCY CUT OFF pot : cut some frequency of the incoming sound
RESONANCE pot : add some harmonics and a little saturation to your signal.
HP / LP (Hight Pass / Low Pass) : a switch to slect what sort of frequencies that you can cut.
INPUT : enter for the signal you want to filter (3 input on this one), a VCO for exemple.
LEVEL INPUT : potentiometer to adjust the input signal (Attenuator)
CV IN : (control voltage) you can control the CUT OFF pot without touch it with your hand with an electrical signal sent by another module, like an LFO (low frequency oscillator), an Envelope (AD/AR or ADSR)
CV ATTENUATOR : adjusts the incoming CV signal
OUT : the out of the module
Exemple of a simple Patch with this 2 modules (VCO + VCF) :
OUT of the VCO (triangle wave for exemple) into the INPUT of the VCF and the OUT of the VCF to your system.