For those who are waiting. I decided to build the voiced/unvoiced detection with separate filters and not to use the control voltage outputs from the NGF Vocoder analyzer. This decision was made because I wanted to stay modular. So the voiced/unvoiced detection can be used for other patches as well. The filters are tested working. The switching circuitry is not yet tested. The PCB’s are ordered. The noise source should be ready within two ore three weeks. Until then here are the draft schematics for the voiced/unvoiced detection: