I’m trying to integrate my Moog Grandmother into my eurorack setup. However, I’ve found that there is a small ground potential difference between the two because they’re running off separate power bricks. I see about a 0.2v difference plus noise/ripple when I feed the Grandmother Env into a VCA on the eurorack powered by a TPS80W.
What’s the best option to make sure they have a clean signal between them?
a) Keep them on separate power bricks, but tie the ground together? (This seems like a bad thing to do. Ground loop? Bad currents between them?)
b) Add a power output jack to the 104hp 7u to directly power the Grandmother’s 12v input 700ma? Make sure the power cable between the two has a ferrite bead on each end. Any thoughts on protection from accidental shorts?
c) Find an mains power supply / brick with separate, isolated 12v outputs? I’ve seen something like this for guitar pedals. But nothing that would handle the TPS80W max power draw.
d) Something else entirely?