The task becomes more difficult when the unit you've isolated has multiple inputs and outputs. On a suspect unit with multiple cables, try various configurations on each connection to find out if special cable assemblies are needed at more than one point. Interconnect chart for locating the following correct cable assemblies. See Figure 4 for suggested cable assemblies for your particular interconnection needs. Then refer to the following wiring diagrams.
Many units come equipped with ground lift switches.
In only a few cases can it be shown that a ground lift switch improves ground related noise. If after hooking up your system it exhibits excessive hum or buzzing, there is an incompatibility somewhere in the system's grounding configuration. If you have an entirely balanced system, verify all chassis are tied to a good earth ground, for safety's sake and hum protection. If you have a mixed balanced and unbalanced system, do yourself a favor and use isolation transformers or, if you're cheap, try the special cable assemblies described here and expect it to take many hours to get things quiet. May The Force be with you.