Thanks for your reply :-)

The RackBrute is not connected to anything else!
I have tested the make noise skiff again, and it actually also exhibits this behavior, with only one module in it (with this module taken out of the RackBrute, the RackBrute feels buzzy). So unless it is multiple modules that causes this, it is not a module problem.

Further, if i touch the ring of the dc plug with one hand, withOUT it being connected to the RackBrute (so it is unpowered and not connected to anything) and touch the RackBrute with the other hand, is also buzzy feeling, as soon as I let go of the dc plug it stops

I just got my Arturia RackBrute 6u. And there seems to be some ac leakage which, when go softly touch the front plates of my modules I can feel a buzz. I also suspect that it messes with my modules, my marbles clock input is super sensitive, and randomly fires if I plug a cable into it. And I can hear slight seemingly random pitch variations in my telharmonic, I use an ungrounded plug. Will changing to a grounded plug work? Or what should I do? I have tried with both the supplied ac adapter, and an ac adapter from my make noise skiff (which don’t have this problem)