Behringer 121 Dual VCF ModuleSYSTEM 100 121 DUAL VCF This is the Behringer SYSTEM 100 121 DUAL VCF Module. An authentic reproduction of the original System 100M circuitry from the 80s that can fit in a standard Eurorack case. The best part? Its at a very affordable price. Mix the 121 DUAL VCF in with your existing rig or start your modular synth journey from here. Either way youre sure to have a lot of fun. Inputs The 121 DUAL VCF features 3 CV inputs and 3 channel mixers per