I just have built one half of the dual CMOS VCF and facing an unexpected issue. 3 of the 4 OTAs are exactly powered like the 4069 chip!
There are -5V at pin 4 of all 4 OTAs and pin 7 of 3 OTAs is connected to 0V! Only pin 7 of the 2nd OTA from the right (pcb in front of me and reading Cynthia)does not go to 0V - not figured out it's connection for the time being).
Since the schematics clearly state that the OTAs should be powered as the TL072 I think the pcb faulty. Am I right or am I missing something?
There are -5V at pin 4 of all 4 OTAs and pin 7 of 3 OTAs is connected to 0V! Only pin 7 of the 2nd OTA from the right (pcb in front of me and reading Cynthia)does not go to 0V - not figured out it's connection for the time being).
Since the schematics clearly state that the OTAs should be powered as the TL072 I think the pcb faulty. Am I right or am I missing something?