to ground or not to ground

Great answers Gs5556 and Jea48! Really learned alot! Thanks.

Maybe you two electricity mavens can help me on a question I have regarding grounding, specifically the safety equipment ground found in the 3rd prong of a properly grounded ordinary wall power outlet.

Is there a way to measure the relative effectiveness of a wall outlet third prong grounding system versus another wall outlet's ground versus a copper rod sunk specifically for grounding purposes of my system? What I mean is that when I took a separate 8' copper grounding rod with a 10 ga. wire attached, and sunk the rod about 15 feet in the ground and then ran the 10 ga. wire through my home's siding and used that as my star-grounding point/source, my system was supremely quiet. Now that I have moved my system to the other side of the house, the grounding rod/wire isn't available anymore, so I am using the wall power outlet's 3rd prong ground. Now the system sounds MUCH dirtier, and it is basically impossible to measure AC voltage on the chassis using this grounding source. It just doesn't register on the DMM. When I had the old grounding system with the copper rod sunk 15 feet into good ol' mother earth, the system was so quiet and the voltages on the chassis so easily ascertainable, that there must be significant differences in grounding potential between the two manners of grounding. A polarity and ground tester, however, shows the wall is correctly wired, including ground. Further, none of my equipment is third pin connected, with the third leg either non-existent (i.e., the two prong plug of my Sony CDP) or defeated (as in my CODA CSi Limited integrated amp.)

A friend said the difference is the relative masses of the ground planes (i.e., more copper of higher purity means more effective grounding, assuming proper placement in the earth.) He said the copper rod I sunk is probably bigger, heavier and more immediate than the house's third prong grounding system, and this accounts for the difference. Does this make sense? On the other hand, the wall outlet 3rd prong grounding connection is supposedly connected to my cold water pipes, thus allegedly tying me into the vastly enormous steel piping system of my water supplier (I live in the mountains north of LA.) Which should be better in theory? In your experience?

Would cleaning the 3rd prong female receptacle possibly make a difference? It could be oxidized, and we all know how oxidized RCAs clog things up and destroy sound quality. Might this also apply to grounding connections as well? I tried using alcohol and a pipe cleaner brush, but it made no discernable difference on the DMM reading for voltage on the chassis. Should I be using a different cleaning agent? Will this make any difference at all?

Again, I think the most important question is whether there is a device to test the relative effectiveness of a grounding system? How do they work and do you know where they are available at a reasonable price?

Sorry for all the questions, but this is really annoying me. I just set the system up yesterday and went to check proper equipment polarity using my DMM and the 3rd prong ground as true ground. I couldn't get a reading of any AC voltage on the chassis, or more accurately, the signal ground plane. This has never happened before, with my RadioShack DMM easily showing the relative voltages between the two plug polarities whenever I have checked for same in the past. However, this is the first time I've used the 3rd prong of the wall outlet as true ground for the DMM.

Oh, yes, I almost forgot. I really don't want to dig up the old grounding rod, or sink a new one, if at all possible. I'm older now, with severe arthritis.

Thanks for any assistance you can offer.

My apartment has a circuit breaker in the breaker box but my audio is not grounded.

Dazzdax, I am going to take a guess here. The receptacle your audio system is plugged into is an old 2 wire type, no equipment safety ground. If all your equipment is plugged into this one duplex receptacle the odds of you getting hit by lightning is better than you getting shocked from your audio system.

Not sure why audio equipment manufactures just don't make all their equipment with double insulated power wiring and eliminate the need for the equipment safety ground altogether. Especially the power amp manufactures that have their signal ground and safety ground commonly connected to the chassis. Then in their owners manual tell the user to use a ground lifter if they experience a ground loop hum problem.

I would agree with Gs5556 post about the signal ground and the safety equipment ground. But in some equipment, especially power amps, the signal ground and equipment ground are connected together putting them on the same ground plane. And for some....the dreaded ground loop hum.
http://www.soundstage.com/weaver01.htm

Thank you for your responses. But are those people who claim that ungrounded audio equipment sound better = crazy?

Chris

I only ground one component in the system, usually the preamp, for best sound. I'm not suggesting that anyone does this. I won't come to your funeral when you fry yourself. YMMV, consult a lisenced electrician, yada yada, etc.

There are two types of grounding: one is the signal zero voltage path which is required for all signals to pass thru the equipment, and the other is the earth safety bonding which is the third prong on the plug/receptacle. Both serve two different functions.

The signal path ground is the zero reference voltage for the signal. It has nothing to do with the ground pin and grounding of the electrical system feeding the unit. This ground is bonded to the chassis at one point or it's a conductor that follows the signal. So it has a big effect on performance.

The earth bond consists of the ground pin of the plug and the safety of the equipment. This ground is bonded to the chassis and has nothing to do with the signal ground. So whether or not the chassis is bonded, floated or grounded will not affect the signal in any way. (I should say "should not affect the signal" to lend me cover.)

Not all audio gear have earth bonding. Some tube amps, for example, have no ground pins - just the old-time two prong cord. The reason is the same as why toasters are not grounded. The live parts are exposed to the outside world and if you should come in contact with them or if damaged, there's less of a chance you'll be electrocuted. If you touch the live filament of a toaster, broken light bulb or tube amp, nothing will happen if you're not grounded. But if a toaster were grounded in this case, then coming into contact with the chassis will prove fatal.

Enclosed equipment, on the other hand, have all live parts enclosed by a metal chassis. A fault will touch the chassis and the earth ground drains the energy away. That's why they have to have the third pin on the plug. Again, it's separate from the signal ground.

Grounds are for safety dont defeat them if there is a ground problem like from the cable tv line or sub hooked into another circuit get a Jensen transformer device. They work great

Why do you say your equipment is not grounded? Have you defeated the ground phase prong on your plugs or used cheater plugs etc.

FWIW, in my experience, defeating the ground, only makes the system sound better if it eliminates a ground loop. I'm anal - I like a dead quiet system all plugged in as the designer provided, but unlike some anal electrical engineers :-)

I have no hesitation to use cheaters on well made audio equipment which just sits stationary on shelves. But I have made myself a promise not to stand in a puddle of water and fiddle with my components.

FWIW