jea48 said:
It does nothing for the sound of an audio system.
@erik_squires response:
I dont’ think this is proven, or even well investigated. If you wanted to show this, you’d have testing done with say, an elevated ground and measurements of noise on the ground wire in a home, and then also do some testing to see how well this noise can or cannot couple to audio systems.
Fact!
Mother earth does not possess some magical mystical power that sucks nasties from an audio system. If anything it can introduce noise onto the AC mains.
Grounding Myths
"Electromagnetic Compatibility Engineering" by Henry Ott
3.1.7 Grounding Myths
More myths exist relating to the field of grounding than any other area of electrical engineering. The more common of these are as follows:
1. The earth is a low-impedance path for ground current. False, the impedance of the earth is orders of magnitude greater than the impedance of a copper conductor.
2. The earth is an equipotential. False, this is clearly not true by the result of (1 above).
3. The impedance of a conductor is determined by its resistance. False, what happened to the concept of inductive reactance?
4. To operate with low noise, a circuit or system must be connected to an earth ground. False, because airplanes, satellites, cars and battery powered laptop computers all operate fine without a ground connection. As a mater of fact, an earth ground is more likely to be the cause of noise problem. More electronic system noise problems are resolved by removing (or isolating) a circuit from earth ground than by connecting it to earth ground.
5. To reduce noise, an electronic system should be connected to a separate “quiet ground” by using a separate, isolated ground rod. False, in addition to being untrue, this approach is dangerous and violates the requirements of the NEC (electrical code/rules).
6. An earth ground is unidirectional, with current only flowing into the ground. False, because current must flow in loops, any current that flows into the ground must also flow out of the ground somewhere else.
7. An isolated AC power receptacle is not grounded. False, the term “isolated” refers only to the method by which a receptacle is grounded, not if it is grounded.
8. A system designer can name ground conductors by the type of the current that they should carry (i.e., signal, power, lightning, digital, analog, quiet, noisy, etc.), and the electrons will comply and only flow in the appropriately designated conductors. Obviously false."
Henry W. Ott
Who is Henry Ott?
http://www.hottconsultants.com/bio.html
The best way to introduce noise as well as a difference of potential, voltage, onto the chassis of audio equipment is by using an isolated dedicated driven earth ground rod.
(isolated dedicated driven earth ground rod? An Earthed grounding electrode that is not connected to the electrical service main grounding system. Therein Grounding Electrode System.)
When an isolated dedicated ground rod is not connected the electrical service Grounding Electrode System a difference of potential will exist between the two earth connected grounding electrodes. Always.
A year ago or so I got into a pissing contest with an EE on another forum. So for a test to prove I was right I drove a 5/8" x 8ft ground rod in the rock garden outdoors by my 2ch audio room. The rod is about 70ft to 80ft from the electrical service’s three 5/8" x 10ft driven ground rods. Also incoming water main piping is 1" copper buried in the earth probably at least 6ft that is part of the electrical service grounding electrode system.
I just did a quick measurement between the two isolated grounding electrodes and I measured 216 - 220 AC mV.
FWIW... The year or so ago test I connected the hot 120V AC conductor of a 20 amp circuit to the isolated dedicated ground rod to prove the 20A breaker would not trip open. And as I already knew the breaker did not trip.