Grounding Systems In Audio Installations

Star Earth

To help prevent hum loops and perfomance degradation, earth connections, both within equipment and systems, are connected in a star arrangement.

Circuit Ground

Electronics circuits all require a ground that is routed through the printed circuit board. The printed circuit boards are contained within a chassis or housing. This has an equipment ground and at one point the circuit ground is grounded to the equipment. This point is the star ground point for the unit.

Shield Ground

The shields of the interconnecting cables are normally grounded. Often this at one end only, usually at the equipment where it terminates. The input/output connector ground pin is connected to a ground within the chassis which is  critically related to the internal curcuitry. Shield grounding also occurs in interim jackfields and a technical ground wire is connected to the to the jackfields for this purpose

Equipment Ground

Every individual piece of electronic equipment within an audio or video system needs to be referenced to ground and this is the equipment ground. This is directly connected to the safety ground of the electrical system via the earth pin of the AC mains power connector. This, of course is a standard safety requirement and should not be tampered with.

Local or Area Technical Ground Reference

This connects to the Master Technical Ground Reference Bus by a single heavy conductor. There may be one or more of these in a facility and located in areas such as control rooms, machine rooms, remote amplifier rooms or mobile truck locations.

Master Technical Ground Reference

Often within an installation of lots of equipment, whether audio, video, computers or whatever, there will be one Master Technical Ground. This is the central hub for all technical ground conductors and is this point that connects the technical ground system to the electrical grounding system for the building. This point sometimes will ground to the neutral conductor for the power distribution.