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To buy grounded or not to buy grounded. That is the question.

I recently happened on to a highly recommended web site and looked at power cord options.  There were two basic options: grounded or non-grounded.  Below is the copied info from the non-grounded cord page.

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"Description
Non-grounded cord  (Ungrounded, the ground wire is removed from cord, with G-plug still intaked)

WHY?

Based upon measurements and listening tests; I have recommended to people, to ground only one piece of their interconnected equipment. The interconnects will provide static dissipation through the secondary ground connection & nuetral. They often look at me in extreme terror.😱

Wikipedia agrees…

Wiki; A ground loop is the result of careless or inappropriate design or interconnection of electrical equipment that results in there being multiple paths to ground where this is not required, so a complete loop is formed. In the simplest case, two items of equipment, A and B, are each connected to a wall socket by a 3 conductor cable, containing a protective ground conductor. This becomes a problem when a interconnect cable is connected between A and B, to pass data or audio signals. The shield of the data cable is typically connected to the grounded equipment chassis of both A and B. There is now a ground loop.

How can you benefit from this? Purchase the Grounded cord to hook to your preamp or integrated receiver…All other power cords in the system, such as source equipment, dacs, amplifiers, subwoofers,etc. should all use the non-grounded cord.  This will direct ground your system, removing hum and reduce harmonic distortion from your system. We’ve seen multi thousand dollar power conditioners that do not fix or address this issue. The issues of ground loops are often greater then the dirtiness of the actual AC power!



Need More?

Hot: The black wire is the hot wire, which provides a 120 VAC current source.

Neutral: The white wire is called the neutral wire. It provides the return path for the current provided by the hot wire. The neutral wire is connected to an EARTH GROUND!!!

Ground: The bare wire is called the ground wire. Like the neutral wire, the ground wire is also connected to an earth ground. However, the neutral and ground wires serve two distinct purposes.

The neutral wire forms a part of the live circuit along with the hot wire. In contrast, the ground wire is connected to any metal parts in an appliance such as a microwave oven or coffee pot. This is a safety feature, in case the hot or neutral wires somehow come in contact with metal parts. Connecting the metal parts to earth ground eliminates the shock hazard in the event of a short circuit. (KEY WORD IS SHORT CIRCUIT, Meaning your electronics are broken!)"

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What think ye of this?

Toolbox149

toolbox149
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cleeds
5,662 posts
 
toolbox149
A ground loop is the result of careless or inappropriate design or interconnection of electrical equipment that results in there being multiple paths to ground where this is not required, so a complete loop is formed.
That is not quite exactly correct. In a typical audio system, multiple paths to ground are often required for safety, with multiple components each enjoying the protection of a safety ground connection. That is only a problem if the grounds are at different electric potentials. Provided the electric potential of each is the same, the "ground loop" will cause no audible problems, such as hum.
Purchase the Grounded cord to hook to your preamp or integrated receiver…All other power cords in the system, such as source equipment, dacs, amplifiers, subwoofers,etc. should all use the non-grounded cord.
That is potentially hazardous, and could result in a component lacking a safety ground to have potentially hazardous current flowing through an interconnect, for which it isn’t designed. It is never wise to defeat a safety ground for anything other than testing purposes.

The solution to a noisy ground loop is not to eliminate a safety ground - that’s throwing the baby out with the bathwater. The proper remedy is to work to get all grounds at the same electric potential.
spatialking's avatar
spatialking
610 posts
 
Cleeds is correct.   When equipment manufacturers put a power cord on with a third prong, they really want you to ground their unit.   Not doing so creates a safety hazard, sometime a lethal one.   Yes, if something internal fails or breaks you can have 120VAC line on the chassis, but that is not the issue of what I saying.   Internal equipment can "leak" line current through parasitic capacitance, mutual coupling, etc. which will put some AC voltage on the chassis.  Touching an ungrounded chassis with a real ground will run that current right through you. 
When you work around electronics and electricity long enough, you will get zapped sooner or later.   Early in my EE career I discovered just how conductive concrete is.  I got seriously zapped just from this, not plugging a power supply ground into a grounded outlet and standing on concrete.
The problem with that third prong is sometimes they get plugged into a different outlet than the rest of the equipment and you get a ton of hum.   There are a number of reasons for this but do what Cleeds stated - get all the grounds at the same potential.  The easiest way to do this is to power everything from one outlet box and use that ground for everything.
n80
2,107 posts
 
If a ground loop is a problem, where do you hear the hum? In the device itself? Through the speakers? Both?

I have had three sources of hum.

1) Cheap TT motor. Needs to go in trash.
2) Second hand Denon tuner. Mechanical sounding hum in the unit.Not heard through speakers. Goes away with book on top. Rarely use it.
3) One instance of hum through speakers when linking Apple TV with DAC via Toslink. Never duplicated. Don’t use this much anyway.

Otherwise, even at max volume my speakers are silent when nothing is being played.

Does this mean that there are no serious grounding or ground loop issues? My house is old but has both water pipe and copper rod grounding.
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