My Final Grounding Question

[Fitzcaraldo215]

If you have two lines feeding your system then your components are on two different grounds, connected at the panel the lines are run from. This creates more potential difference and more SCIN, shield current induced noise. By lifting grounds now your entire system is running on whatever ground your preamp is plugged into, which is much better from a grounding perspective but not from a safety perspective.

The best solution is to plug your entire system into a single power distribution block with all the grounds in that block tied together at one point, this block should be plugged into one outlet. If you really need two lines (unlikely) then you should have two power distribution blocks as described, with their grounds tied together using a heavy gauge (12g+) wire.

This will solve your ground issues and make your system sound the way it is now, but will not be dangerous. Right now your components are grounded through your IC cables... IC cables are not designed to carry fault current!

You may be right in some circumstances. But, while inelegant, the main breaker box might well provide the same degree of "star grounding" on multiple different circuits. It has the advantage via additional circuits of providing much more amperage distributed as you wish to high current draw components. Unless your electrical wiring is weird or compromised, I think this may be much better than powering all components from a single circuit. That is especially true if you can ensure with your electrician, that all circuits are near identical in hookup to the main box, ideally on the same phase of the typical US 3-wire main power feed.

For decades now, I have had multiple 20A circuits feeding my music room, one for the main amps, another for my subwoofer, another for low current components, etc. My interconnects are all XLR. There has never been any hum or ground loops, except...
When I upgraded to PC audio playback (it was a sonic upgrade), initially it was connected to an existing house circuit. I did get hum. So, I ran an extension cord from the PC into the music room, and plugged it into the same circuit my low draw audio components were on. Problem solved.

 

[Speedskater]

http://www.audioasylum.com/audio/speakers/messages/198058.html

It's trouble some that he would suggest such an unsafe thing with small children in the home.
The simple solution in an older 2 wire home is a GFCI receptacle or circuit breaker.

 

[DaveC]

You may be right in some circumstances. But, while inelegant, the main breaker box might well provide the same degree of "star grounding" on multiple different circuits. It has the advantage via additional circuits of providing much more amperage distributed as you wish to high current draw components. Unless your electrical wiring is weird or compromised, I think this may be much better than powering all components from a single circuit. That is especially true if you can ensure with your electrician, that all circuits are near identical in hookup to the main box, ideally on the same phase of the typical US 3-wire main power feed.

For decades now, I have had multiple 20A circuits feeding my music room, one for the main amps, another for my subwoofer, another for low current components, etc. My interconnects are all XLR. There has never been any hum or ground loops, except...
When I upgraded to PC audio playback (it was a sonic upgrade), initially it was connected to an existing house circuit. I did get hum. So, I ran an extension cord from the PC into the music room, and plugged it into the same circuit my low draw audio components were on. Problem solved.

Well, reducing potential between grounds reduces noise so it's best to do what you can. The main panel is always going to be further away so it's actually impossible for the panel to do the same job grounding, there will always be more resistance. If the service panel is close to the audio system then maybe it's not a problem. For a great majority of systems there won't be an advantage to multiple lines, but there are always exceptions. For those exceptions if you ground the system the way I described you're still star grounding the system at the power distribution which is far better than the grounds connecting way back at the panel. It's also not that difficult to install a breaker box/subpanel for your system in the audio room, then run multiple lines from the breaker box/subpanel. So yes, you can run multiple lines from the main panel and hope for the best but there are better solutions that will result in a system with less noise.

If the system is powered more ideally the aftermarket grounding systems should make much less of a difference with the only advantage being the piezo ground filtering, but that's not exactly worth tens of thousands of $...

 

[Fitzcaraldo215]

Well, reducing potential between grounds reduces noise so it's best to do what you can. The main panel is always going to be further away so it's actually impossible for the panel to do the same job grounding, there will always be more resistance. If the service panel is close to the audio system then maybe it's not a problem. For a great majority of systems there won't be an advantage to multiple lines, but there are always exceptions. For those exceptions if you ground the system the way I described you're still star grounding the system at the power distribution which is far better than the grounds connecting way back at the panel. It's also not that difficult to install a breaker box/subpanel for your system in the audio room, then run multiple lines from the breaker box/subpanel. So yes, you can run multiple lines from the main panel and hope for the best but there are better solutions that will result in a system with less noise.

If the system is powered more ideally the aftermarket grounding systems should make much less of a difference with the only advantage being the piezo ground filtering, but that's not exactly worth tens of thousands of $...

Agreed, reducing differences in ground potential is a good thing. But, if you have multiple dedicated circuits of identical length and cable characteristics going from adjacent duplex outlets and to adjacent breakers in the main panel, it is hard to envision, let alone measure, a difference in ground potential. Length is not the issue when it comes to differences in ground potential, though it could in extreme circumstances raise the absolute level of impedance in the ground equally in all the dedicated circuits. A sub panel may be no better in that regard.

 

[amirm]

It's trouble some that he would suggest such an unsafe thing with small children in the home.
The simple solution in an older 2 wire home is a GFCI receptacle or circuit breaker.

I cringed after reading that too. Kids routinely find things to poke into outlets. I would not at all be surprised if they did the same with audio equipment through their vents. Speaking from personal experience, even though we had capped all of our outlets, one day we found one highly charred with the cap removed, clearly indicating one of our kids had inserted something metallic in there, causing a short. Thank heavens there is no voltage during a short but imagine if one leg had gone into the hot terminal before the other.

 

[DaveC]

Agreed, reducing differences in ground potential is a good thing. But, if you have multiple dedicated circuits of identical length and cable characteristics going from adjacent duplex outlets and to adjacent breakers in the main panel, it is hard to envision, let alone measure, a difference in ground potential. Length is not the issue when it comes to differences in ground potential, though it could in extreme circumstances raise the absolute level of impedance in the ground equally in all the dedicated circuits. A sub panel may be no better in that regard.

The additional length of wire causes more resistance and there is always some difference is ground potentials, so there will be more noise, it's just the way it works. The subpanel would definitely be better if it's closer to the audio system, which would be the whole point of using one... if it's not much closer to the audio system then there's no point in using a subpanel.

These are all pretty easy things to do when running power for your system, you might as well do it right. You're trying to justify cutting corners, and it might very well work fine, but there will be more noise and you might as well do it the best way possible right from the start. Unless you've tried doing it both ways and measured the result you're speculating... it could very well be that improving your grounding could improve the sound of your system and reduce noise.

 

[ack]

The additional length of wire causes more resistance and there is always some difference is ground potentials, so there will be more noise, it's just the way it works.

Yes, you are absolutely right, even if for that of minutest of differences. Which is why I also always recommend same-length and brand/model cords when star-grounding at the power strip, as mentioned earlier.

 

[Speedskater]

Agreed, reducing differences in ground potential is a good thing. But, if you have multiple dedicated circuits of identical length and cable characteristics going from adjacent duplex outlets and to adjacent breakers in the main panel, it is hard to envision, let alone measure, a difference in ground potential. Length is not the issue when it comes to differences in ground potential, though it could in extreme circumstances raise the absolute level of impedance in the ground equally in all the dedicated circuits. A sub panel may be no better in that regard.

The idea of a sub-panel in or near the listening room, is to reduce the length of the Safety Ground/Protective Earth wire from audio component to audio component.
And a side benefit of the sub-panel is that it's larger SG/PE wire back to the main-panel Neutral will have a lower resistance than the two separate SG/PE wires.

 

[DonH50]

I thought I had written this long ago, but added it today in case it is helpful. Ground Loops 101

 

[Fitzcaraldo215]

The idea of a sub-panel in or near the listening room, is to reduce the length of the Safety Ground/Protective Earth wire from audio component to audio component.
And a side benefit of the sub-panel is that it's larger SG/PE wire back to the main-panel Neutral will have a lower resistance than the two separate SG/PE wires.

Not to belabor this, but, aren't you implying that the safety ground and Neutral conductor in any common US 15 or 20 amp circuit with ground which is correctly wired with the appropriate wire gauge to the main panel is potentially insufficient? Ergo, the sub panel is better, safer, etc.? I wonder, then, why electrical codes and UL certifications allow current wiring practices, wire gauges, etc., usually avoiding sub panels, if that is true.

No doubt sub panels can fix problems for many, especially in older homes or with other unique wiring problems. I do not feel the need, myself.

 

[Speedskater]

Not to belabor this, but, aren't you implying that the safety ground and Neutral conductor in any common US 15 or 20 amp circuit with ground which is correctly wired with the appropriate wire gauge to the main panel is potentially insufficient? Ergo, the sub panel is better, safer, etc.? I wonder, then, why electrical codes and UL certifications allow current wiring practices, wire gauges, etc., usually avoiding sub panels, if that is true..............................................

I'm not writing about safety, the government's electrical codes well cover safety.

The only safety issues in threads like these are:
a] Creative ground rod installations that compromise the integrity of the AC power system.
b] Modifications to Safety Ground/Protective Earth conductors.

What I am writing about is reducing noise on low level signal lines that are connected to the same equipment high voltage high power AC power lines.
The idea is to reduce leakage, noise, interference, lost Neutral and Ground currents that may use our signal lines to get back to their voltage source.