I recently bought a stereo TRS 1/4" male to 2x mono 1/4" female adapter for my NS/Stick. No matter what cables I use, the melody side (red) emits an abrasive static-like buzz, but only when a cable is plugged into the bass side (black) as well. In other words, when I unplug the instrument cable from the black side of the adapter, the buzzing on the red side stops. I feel like something isn't grounded properly when both are plugged in. Should I be using a different setup, i.e. is there some reason only a full-length splitter cable would work as opposed to 2 cables going into my merger adapter?