The Cyndustries List

I am a bit confused on what is needed for intergrating an outside
modular with a modcan/cyndusatries system. I have a Frac rack 1/8"
system and would liek to freely patch that into my Cyndustries system.
I have noticed that most patch panel modules (ie: Modcan 25A
Interface, Synthesizers.com Q121 banana interface) do not have a
ground. Yet the MOTM 940 patch panel does. When is it necessary to
have a groud. Can I just plug a vco from my Doepfer into the Modcan
filter with no concern for buzzing etc? When I use my Fenix I've
noticed I have to use the ground. Is this only for other banana
connections?

Any help appreciated.