Ground rod length
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NO, NO, NO!
All the ground rods in a building must be connected together at one point and connected to the AC power system at the service entrance/main breaker panel.
Ground rods and other connections to Planet Earth are only for safety during unusual events (like thunderstorms).
Ground rods have nothing to do with day-to-day AC power quality.
Planet Earth does not act as a sink or sump for bad electricity.
All the ground rods in a building must be connected together at one point and connected to the AC power system at the service entrance/main breaker panel.
Ground rods and other connections to Planet Earth are only for safety during unusual events (like thunderstorms).
Ground rods have nothing to do with day-to-day AC power quality.
Planet Earth does not act as a sink or sump for bad electricity.
Well the way I understand this issue your house needs a safety ground that conforms to code for things like lightning strikes. Your needs for an audio noise floor unimpeded by ground loops is an entirely different matter. As Kevin indicated you should not tinker with your safety ground but that does not preclude you form setting up a separate ground for your system that will pay huge benefits if you want a low noise floor. (All of these grounding boxes discussed on forums effectively accomplish the same thing.) The goal is to maintain the exact same electrical potential at the ground of each outlet so stray voltage generated at any individual component exits the system through the ground of that component as opposed to traveling across interconnects to other components to exit through that components ground. This traveling of such stray voltage across cables is a ground loop which creates noise.
I use a star ground system with 5 Furutech NCF lines and outlets grounded to a 1" by 8' copper rod sunk into a 2' diameter hole filled with 300 lbs of Harger Ultrafil grounding mix immediately behind my listening wall. (This is in addition to the main safety ground for the building.) This is effectively the same thing as a grounding box but far more effective. The need for a second grounding rod is in the event you do not have good soil for conductivity. You can mitigate this concern by using the Ultrafil in the hole which assures excellent conductivity and electrical sink; better than any available grounding box. (You can't fit 300lbs of grounding mix and 24 lbs of copper in a little box.) All 5 of my outlets use a harness with equal 6' length furutech NCF lines connected to the ground rod (made by Scot Markwell). This brings electrical potential to near zero but more importantly makes it identical at all 5 outlets. My ARC phono and Soulution amps are dead quiet.
I use a star ground system with 5 Furutech NCF lines and outlets grounded to a 1" by 8' copper rod sunk into a 2' diameter hole filled with 300 lbs of Harger Ultrafil grounding mix immediately behind my listening wall. (This is in addition to the main safety ground for the building.) This is effectively the same thing as a grounding box but far more effective. The need for a second grounding rod is in the event you do not have good soil for conductivity. You can mitigate this concern by using the Ultrafil in the hole which assures excellent conductivity and electrical sink; better than any available grounding box. (You can't fit 300lbs of grounding mix and 24 lbs of copper in a little box.) All 5 of my outlets use a harness with equal 6' length furutech NCF lines connected to the ground rod (made by Scot Markwell). This brings electrical potential to near zero but more importantly makes it identical at all 5 outlets. My ARC phono and Soulution amps are dead quiet.
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Paul,
That is what I want to do. However, as Kevin mentioned, all ground rods must be connected together. Your second ground rod may not be at the same potential as the house ground rod. In a thunderstorm, there is danger that your equipments connected to second ground rod got fried. I read a bit around the internet. It is still beneficial to install second ground rod and connected to the house ground rod as it will lower the resistance of the whole ground rod.
That is what I want to do. However, as Kevin mentioned, all ground rods must be connected together. Your second ground rod may not be at the same potential as the house ground rod. In a thunderstorm, there is danger that your equipments connected to second ground rod got fried. I read a bit around the internet. It is still beneficial to install second ground rod and connected to the house ground rod as it will lower the resistance of the whole ground rod.
Sorry if I wasn't clear. The ground rod for the audio system is in addition to the safety ground at the main entrance of the building meaning it is attached to the main entrance safety ground but is local to the audio system which brings the potential at all five outlets used by the audio system to the same level thereby avoiding ground loops.
Absolutely correct; I have (and was educated on this by a master electrician who is also an audiophile), 2 ground rods, 8 feet long each, separated by 7+ feet (8 was not possibly) and joined by solid copper (4-gauge) wire.
Single most important thing beyond that (IMHO) is to NOT use typical attach clips for ground wire through/to the top of the rod. Have your electrician give measures to an electrical supply house and spend the couple of
hundred extra $$$ on a "CADWELD KIT" allowing for 2 welds; the CADWELD process will permanently and completely bond the ground wire to ground rod #1, then to ground rod#2 prior to it running into the attach point
to your home's main electrical connection.
The 2nd ground here (installed well over 2-2.5 years ago here) with this CADWELD bonding and spending the extra money on the large-gauge lead wire gave me immediate and noticeable results.
Any questions, please let me know....
Another thing you may want to try is the use of an Environmental Potentials EP-2050 Wave-Form regenerator/surge-suppression unit on your main house panel and EP-2750 Ground Filters on any
audio or video circuit in your main and/or sub-panels. Of course, if you are fortunate enough to have an isolation-transformer panel like Mike Lavigne & others or other solutions (stand-alone
isolation transformer(s)), you won't need the EP-2050.
The above gave me a sound quality (and video quality on the UltraHD 4K panel in the living room as a great side effect) that I've not experienced in all homes/audio rooms prior to this.
Thank you SC Audiophile. I have Equitech 10k VA balanced isolation transformer like Mike. Equitech website did give useful information how to install second ground system. If I understand correctly, they suggest to star ground the center tap of the output transformer and the outlets and then connect to the ground rods. And these ground rods connected back to the house ground rods.
How deep did you put the ground rods? What type of ground rods do you use? Galvanized copper?
The key to grounding is not found with copper rods. It has far more to do with whether the grounds of the various parts of your system are properly executed.
If they are, you will find the ground stake to be of no benefit whatsoever. If they are not, you might hear a change with the ground stake. The problem here has already been outlined- if you have a stake right outside of your audio room and that is where your equipment is grounded, you do stand a pretty good chance of the entire system being damaged by a lightning strike on the AC power lines (which means it does not have to be a strike all that close to your house).
How should the equipment be grounded? The chassis should be connected to the electrical ground via the power cord.. The audio ground should not be the same as the chassis. So if you were to use a DVM set on Ohms scale, and you measured from the chassis to an audio connector, you would find that its not a direct short. If it is, the equipment will be vulnerable to ground loops. The exception here is balanced line equipment, but this only works if all the equipment is balanced and not only that, but all the gear should support the balanced line standard (otherwise known today as AES file 48).
If the equipment is not grounded at all (open between the chassis and the ground connection of the power cord) then it can be dangerous if things go wrong (for example the power switch on the front panel is damaged and shorts to the chassis).
So there is the safety bit of this, and then there is the sonic bit. It just so happens that if both are served correctly, you get the best of both: electrical safety and the lowest noise. Ground stakes really have nothing to do with it- they only help if things are already messed up, and they often cause complications of their own.
If they are, you will find the ground stake to be of no benefit whatsoever. If they are not, you might hear a change with the ground stake. The problem here has already been outlined- if you have a stake right outside of your audio room and that is where your equipment is grounded, you do stand a pretty good chance of the entire system being damaged by a lightning strike on the AC power lines (which means it does not have to be a strike all that close to your house).
How should the equipment be grounded? The chassis should be connected to the electrical ground via the power cord.. The audio ground should not be the same as the chassis. So if you were to use a DVM set on Ohms scale, and you measured from the chassis to an audio connector, you would find that its not a direct short. If it is, the equipment will be vulnerable to ground loops. The exception here is balanced line equipment, but this only works if all the equipment is balanced and not only that, but all the gear should support the balanced line standard (otherwise known today as AES file 48).
If the equipment is not grounded at all (open between the chassis and the ground connection of the power cord) then it can be dangerous if things go wrong (for example the power switch on the front panel is damaged and shorts to the chassis).
So there is the safety bit of this, and then there is the sonic bit. It just so happens that if both are served correctly, you get the best of both: electrical safety and the lowest noise. Ground stakes really have nothing to do with it- they only help if things are already messed up, and they often cause complications of their own.
I believe my equipment from Esoteric is properly executed, the know after exhaustive work after moving in that the house electrical system, the listening room sub-panel and grounding solution for the house is as well. I don't agree with you that the only reason systems improve in sound quality after all this work is that something must be messed up to begin with....if you could explain a bit more about your statements, that would be helpful. Thanks!
My ground rods are solid copper and from ALT, specifically model #2903-8 (8-foot long). I chose these for their long-term anti-corrosive qualities (reported to be > 30 years).
I hear from other audio folks and some ham radio operators for which this is important that 10mm thick copper-clad over steel is also an acceptable solution but I went with
solid copper just in case.
They are impact-driven almost 9 feet down and the CADWELD-bonding is at the top of the rods approximately 10-12" below the surface...
I would not suggest galvanized steel as it is reported to corrode on a much shorter timeline (10 years I think at maximum...).
If anyone has better facts here, please chip in!
Actually, SurgeX has found the maximum surge due to a close-by lightning strike to be about 6kV. A direct strike can be a lot more.
Its pretty simple. If the chassis of an amplifier is not connected to the circuit ground but it is grounded, then it is a more silent noise shield for the amp. The other obvious benefit is that if tied to something else, ground currents between the various bits of the audio chain can't form a ground loop. If things are going right, a stake in the ground will make no improvement whatsoever. The fact that it did something for you really suggests that something was amiss to start with.
Belief is good- knowledge is better. Get a DVM and see if your gear is in fact properly grounded.
Ralph, I know you know your stuff but maybe you can help me out here. The benefit of the local earth ground is to bring potential to the same level at each wall outle'ts ground so each chassis sees the same potential and thereby grounds to the outlet into which it is plugged. You seem to be completely ignoring the fact that all sorts of things from run length and wire gauge to induction loops can cause potential to vary at each outlet ground which causes stray voltages at the respective components to run across components through interconnects causing ground loops. IMO you seam to be saying a local ground rod isn't going to help unless you need a local ground. Your whole premise is predicated on equal potential at each outlet which is the whole reason for the local rods from the start.
Sure.
Refer to the first statement I put in bold above. It is false, for at least two reasons I can think of.
First, the part about different potentials is not correct. All the ground connections at the wall will be at the same potential unless the outlet is miswired. That potential is ground potential.
The second is there had better not be any current in that ground connection at the wall! If there is, it points to a malfunction somewhere that should be corrected. You aren't going to solve a ground loop problem by adding a ground rod if the designer of the equipment hasn't done his homework! You're still going to have a problem. Just so we are clear, ground loops don't always manifest as hum but they can still affect the performance of the equipment that is in the loop.
Now refer to the second bolded statement. It too is false. In this case, you are making the assumption that somehow the ground rod will be somehow immune to the same problems to which you refer earlier. It isn't. Whatever equipment is causing ground loop problems will continue to do so whether the ground rod is there or not. It much easier to stop a forest fire by blowing out the match; just get the equipment fixed so it works right in the first place.
But all the ground rods for a building must be connected together at a single junction and connected to the power company Neutral at the building service entrance/main breaker panel. A circuit's Safety Ground system also connects to that Neutral. The Safety Ground wire has to follow the same path as the Hot & Neutral back to the main breaker box.
There is no way for the audio system power to have a local connection to Planet Earth.
But then there is no need for such a connection.
As I wrote before:
Ground rods have nothing to do with day-to-day AC power quality.
This misunderstanding started a long time ago when:
a] Knob & Tube systems did strange things with the Neutral wire. Like using one circuit's Neutral in another circuit.
b] All metal water pipes connected several building together. In lost neutral problems, the water pipe would function as a neutral.
To repeat myself:
Planet Earth does not act as a sink or sump for bad electricity.
Perhaps a little illustration will help folks understand how grounding works - notice how the outlet's neutral and ground wires (white, green) are 'bonded' at the breaker panel, and then both connected to earth ground
Better still, read the entire MIT article at http://web.mit.edu/jhawk/tmp/p/EST016_Ground_Loops_handout.pdf
Better still, read the entire MIT article at http://web.mit.edu/jhawk/tmp/p/EST016_Ground_Loops_handout.pdf
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You can better your ground by adding but it should never ever be separate. They must be tied together!
If you are trying to better lightning protection, then tying in more ground rods is beneficial. But they must all be slaved together to that common point entrance. Due to attempting to dissipate the current of a lightning hit, the general rule of thumb is that you have benefit by separation distance same as the length of the rods. So 8ft rods, then separate by about 8ft. Closer doesn't gain you anything. Cad welding is the best for the connections when doing that too. Now what will throw an electrician....is tying together the separate rods is best done with flat copper strap rather than just heavy gauge stranded copper. The reason being, bandwidth. Lightning has energy all over the place frequency wise. You want low impedance to ground as broadly as possible. Hence the connection from the panel should be as short and direct as possible to ground and have gentle bends always.
CJ
If you are trying to better lightning protection, then tying in more ground rods is beneficial. But they must all be slaved together to that common point entrance. Due to attempting to dissipate the current of a lightning hit, the general rule of thumb is that you have benefit by separation distance same as the length of the rods. So 8ft rods, then separate by about 8ft. Closer doesn't gain you anything. Cad welding is the best for the connections when doing that too. Now what will throw an electrician....is tying together the separate rods is best done with flat copper strap rather than just heavy gauge stranded copper. The reason being, bandwidth. Lightning has energy all over the place frequency wise. You want low impedance to ground as broadly as possible. Hence the connection from the panel should be as short and direct as possible to ground and have gentle bends always.
CJ
Ralph and Kevin,
I kinda think we are talking about two different things. An old school ground loop from a bad equipment ground design that causes an obvious humming is not the issue. Those issues where cleaned up by any competent designer long, long ago and of course, as Ralph indicates, the fix for this problem should never even be attempted with a local stray voltage sink as we are discussing. The problem we are talking about assumes the equipment is properly designed and is a much more subtle issue related to noise floor.
The concept I think the OP, SCAudiophile and I are addressing is the very low level hash in the noise floor of highly resolving systems that is caused by stray voltages at the equipment induced by motors, switch mode power supplies and digital electronics which in turn run across the ground in equipment interconnects if the ground potential at outlets is not equal. Ralph, when you say all outlets have equal potential and this potential equals that of earth ground it is clear to me we are talking apples and oranges. I am referencing small potential differnces that are caused by the ground wire length and gauge differences and ground wire proximity to current carrying wires that induce potential in the ground cable. These small potential differences cause induced stray voltages in the equipment to travel across interconnects to the outlet with the lowest impedance causing the hash in question.
People clean this up by grounding the equipment to local ground boxes or even in some cases blocks of copper. Both work great. (Read any of the many threads on ground boxes.) The fear I have is how these devices work if the equipment housing actually shorts at some point. I prefer having the short run directly from all outlets as a star to a rod in the ground rather than a device in my room. This rod of course must be tied to the central ground of the facility for code and be surge protected for lightning strikes that can run between multiple ground points due to earth ground potential differences. This is common practice in telecommunications.
I kinda think we are talking about two different things. An old school ground loop from a bad equipment ground design that causes an obvious humming is not the issue. Those issues where cleaned up by any competent designer long, long ago and of course, as Ralph indicates, the fix for this problem should never even be attempted with a local stray voltage sink as we are discussing. The problem we are talking about assumes the equipment is properly designed and is a much more subtle issue related to noise floor.
The concept I think the OP, SCAudiophile and I are addressing is the very low level hash in the noise floor of highly resolving systems that is caused by stray voltages at the equipment induced by motors, switch mode power supplies and digital electronics which in turn run across the ground in equipment interconnects if the ground potential at outlets is not equal. Ralph, when you say all outlets have equal potential and this potential equals that of earth ground it is clear to me we are talking apples and oranges. I am referencing small potential differnces that are caused by the ground wire length and gauge differences and ground wire proximity to current carrying wires that induce potential in the ground cable. These small potential differences cause induced stray voltages in the equipment to travel across interconnects to the outlet with the lowest impedance causing the hash in question.
People clean this up by grounding the equipment to local ground boxes or even in some cases blocks of copper. Both work great. (Read any of the many threads on ground boxes.) The fear I have is how these devices work if the equipment housing actually shorts at some point. I prefer having the short run directly from all outlets as a star to a rod in the ground rather than a device in my room. This rod of course must be tied to the central ground of the facility for code and be surge protected for lightning strikes that can run between multiple ground points due to earth ground potential differences. This is common practice in telecommunications.
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