I'm sure this is a "ground" issue, but I'd really like to better understand what's going on.
I have a bass guitar plugged into the "instrument input" on my interface (ART TubeFire 8). When I monitor that channel, I hear a buzzing sound that goes away whenever I touch either the metal plate where it's plugged into the bass, or the little spring on the cable shielding.
The thing is, it only works when my hands are touching these items. Of course, I can't play whilst acting as a human ground, so I am trying to find some alternative.
I've tried balanced and unbalanced cables, and also added a direct box. The direct box helps in that it gives me more places to touch, but it doesn't affect the buzzing per se.
I imagine that the bass itself could be the problem, as it's about 20 years old. But it sounds perfectly fine when I "manually" ground it.
What's going on?