Originally Posted by teknosmoker
I am just uncertain as to how to go about doing it correctly.
Plug in your synth and take a tiny jumper cable and attach one end to the rear jack ground of the upper row (synth output) to the rear jack ground of the lower row (console input). If the ground hum goes away, I suggest taking a 20 guage bare wire and connecting (soldering) all the ground jacks on the rear of the bay together. (Big circle all around the bay).