Jim is correct. Bonus is that many VCAs have attuenuator/mixer built in so can get more bang for buck and space. My Intellijel Quad VCA and Befaco Hex VCA have these features which are nice. I feed mine from VCA to Doepfer Polarizing mixer and then to Intellijel Mixup then to external mixer. I still need a matrix mixer and another attenuator and switch. Can never have too many of these utility modules. If you look at prebuilt modular systems, most of the modules are utilities and support modules. Out of a 6U setup, only 1-2 modules are voices or oscillators with 1-2 filters! Take a look at the Make Noise Shared System, Erica Synths Black System and so forth. These only have a few sound modules. The rest are mixers and tools.