The issue isn’t connectors, but the signal levels – electronic circuits generally don’t like input voltages outside the supply rails. CD4000 inputs are speced for −0.5 V to VDD+0.5 V, so in your case going above 5.5 V may damage the chip.
Some opamps like the TL074s are even pickier; they can misbehave if you get closer than 4 V from the negative supply (see here).
The 4SEQ linked above solves that by powering the opamps with ±12 V and the CD4000s with +12 V only, and using diodes on the way in, to avoid exposing the CD4000s to negative voltages. The input stage uses opamps as comparators, with a threshold of 12×10k/(100k+10k) = 1.1 V. Here’s one of the inputs:
That’s for a non-inverting input; swap the + and − inputs if you need inverting (i.e. the CD4000 input is marked with an ▻ or written like T̅H̅I̅S̅). Also, that circuit will still mess up if the input goes a bit below −8 V, but it should handle inputs from −8.5 to at least 11 V just fine.
EDIT: Updated image to include the R89 pulldown, which is needed to avoid floating inputs.