Hi Peter

> If I plug headphones directly into a module's output then I don't hear it. When I plug the module's output into my audio interface, then I get the noise/hum. This is what leads me to believe it's a ground loop. Am I correct If so, how do I remove it safely A DI box with a ground lift feature

I assume it is an interface, which is powered via the datacable from the
computer. If i am right, then the solution will be either powering the
interface via an separate powersupply, or connect the Doepfer to the
computers interface via an passive DI split box (means ot
electronically, but true split with a transformer).

This problem happens very often with computers with separated LCD
monitors (e.g. at our sessions it happes to two persons with Apple
MacMini plus monitor), but also sometimes with laptops.

Florian