Midas Consoles U16, U32, U24 Appendix E Best Grounding Practice, Safety first, Ground loops

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Appendix E: Best Grounding Practice

This appendix gives details of the best grounding practices for the VeniceU console in order to get the optimum performance out of it.

Safety first

The VeniceU is classified as a class 1 device and as such there is a safety requirement for the power cable to provide an earth connection to the console. This connection is bonded to all external metal parts such that in the event of a failure within the AC power systems it is impossible for any external parts of the product to become live. When connecting other equipment to the VeniceF to form an audio system, it is likely that some of these additional devices will also be class 1, so they will require a safety earth too. For your own safety, the safety of others and to comply with the law, it is important that none of these earth connections are tampered with in any way.

Ground loops

When connecting audio signals or data between devices within an audio system, a signal ground connection must be provided that screens the signals from electromagnetic interference. This ground connection, combined with the safety earth, produces a ring of conductors often referred to as a “ground loop”. Typically, this gives rise to induced currents within the components of the loop, namely the ground conductors, the chassis of the equipment and the safety earth conductors. This is not dangerous, but if the grounds are used as a reference for audio signals, as occurs with unbalanced connections, the ground currents may generate small voltages that corrupt the signal integrity. The audible results are noise added to the intended signal. Typically, this sounds like hum (from the power AC voltage), buzzing or whistles (from power supply diodes or switch mode power supplies), or digital noise (from computers).

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