Not sure what happened

[PrinceOfAnarchy]

Hello all. I've been a digital musician hobbyist for about 6 years. I'm just now considering elements related to powering devices and speakers.

I'm renting an older house. I started using a 3 light indicator to check the outlets. Some are grounded, while others test as up open ground. Although I'm still trying to learn how electricity works and how it impacts audio systems, it seems like my best bet will to be to run my audio equipment off grounded connections and try to avoid 3 prong devices on the open ground receptacles. My plan is to move out of this house, so I'm not too concerned about updating the open ground outlets.

Here's where I got totally confused, though. I have an outlet reading "open ground" on the 3 light tester. But, when I plug in a PDU into the circuit the lights change to show correctly grounded wiring. I have different brands of PDUs. The outlets remain showing open ground when I plug in my Tripp-Lite PDUMH15. But, the lights change to show grounded wiring when I hook my Synaccess MP-1001E into the circuit.

So, what is this telling me about my Synaccess PDU? I noticed it has a ground symbol on the front with a small hole. I am so confused as to what is going on. I thought the only way to be grounded was to be linked to a grounding rod outside the home. Why are the outlets testing as grounded when I plug in the Synaccess PDU? Why do they still show open ground when I plug in the Tripp-Lite PDU?

 

[sagor1]

When you plug equipment into the socket, the equipment is probably providing a ground between neutral and ground, assuming you are using a 3 pin plug (North America). The outlet is still faulty...

 

[PrinceOfAnarchy]

When you plug equipment into the socket, the equipment is probably providing a ground between neutral and ground, assuming you are using a 3 pin plug (North America). The outlet is still faulty...

I assumed the outlet was still faulty and the circuit was not truly grounded. Can you explain what you mean by "the equipment is probably providing a ground between neutral and ground"? What would be the application of this feature?

 

[jewlersarty]

I think you should watch YT tutorials regarding this issue. It would help.

 

[sagor1]

Both of those PDU have current measurement devices inside - electronics that are using the outlet for power. It is possible one of those devices has some link to ground via that measuring device, hard to tell for sure. The link to ground could be very weak, like a 1Megaohm resistor (like some powerline filters). That may be enough that the device thinks the ground is good. That is all a wild guess, but bottom line is the outlet is faulty to start with and you should not be using a faulty outlet for electronics (or anything for that matter). Also, I would trust the PSU that shows the open ground indicator, not the one that thinks it is good.

 

[Tony Stewart]

The PDU will contain two Common Mode choke caps to the PE ground ( 1 to 4.7 nF) that act as a bidirectional low pass filter. They draw much less than 1 mA for UL or <2.5 mA for CE ( I recall) but that is enough to make a primitive ground tester give this result. I expect it is looking for a low voltage difference between N & Gnd when injecting say 100 uA of current with some other signal from the tester. Since one expects ground and neutral to be < 100 ohms back to the PE connection or the sub-distribution transformer, it is a false reading.

In theory "ground" is wherever you define 0V and extend that elsewhere with some tolerances for noise or current and resistance. Protective Earth, PE aka "ground pin" follows the same reasoning, so since your tester measured near 0V on the ground relative to Neutral, it assumed the ground was connected but didn't test it with 10A but rather something much smaller to check for low voltage difference.

However, this is a false reading.

 

[PrinceOfAnarchy]

I think you should watch YT tutorials regarding this issue. It would help.

I've never seen a YT video explaining how plugging in a PDU will change the reading on an outlet tester. I'm sure Tony Stewart has it correct in his explanation. The only problem is it's too over my head. Open Ground on the tester made sense to me - no connection to the EGC. Plugging in equipment and seeing the test results changed is where I got lost.
I've been doing kind of a deep dive into electricity, currents, voltage, breakers, ground faults, noise filters, etc. I've been learning a lot, but it's also been a lot of learning how much there is to learn and how much I don't know. I've gained a ton of respect for electricians. I'm going to keep learning, but ultimately the main thing I've learned is I'm probably never going to be a DIY electricity guy. But, I still think it's good for me to understand some of the general concepts.

One of my goals is to get good power quality for audio. I'm planning to move out of my current home, so I'm not concerned with my open grounds. I've been here for 7 years and never realized I had them. I'm wondering a bit though now if the open grounds actually improve my audio quality. I've heard a lot of noise can travel along the ground wire.

I was curious about the behavior where the tester changed when plugging in a PDU. I thought I would ask about it and maybe learn something. But, mainly, I'm trying to plan for my next home. It sounds like the #1 thing I can do is have an electrician wire me up with a dedicated line to my recording studio as well as my hi-fi room. I've also read that the dedicated lines should be on a separate phase as major appliances and GFCI outlets. I might not have too much control over that, though. But, I do plan on going with dedicated lines, and possibly isolated grounds as well.

 

[Nigel Goodwin]

I've never seen a YT video explaining how plugging in a PDU will change the reading on an outlet tester. I'm sure Tony Stewart has it correct in his explanation. The only problem is it's too over my head. Open Ground on the tester made sense to me - no connection to the EGC. Plugging in equipment and seeing the test results changed is where I got lost.
I've been doing kind of a deep dive into electricity, currents, voltage, breakers, ground faults, noise filters, etc. I've been learning a lot, but it's also been a lot of learning how much there is to learn and how much I don't know. I've gained a ton of respect for electricians. I'm going to keep learning, but ultimately the main thing I've learned is I'm probably never going to be a DIY electricity guy. But, I still think it's good for me to understand some of the general concepts.

One of my goals is to get good power quality for audio. I'm planning to move out of my current home, so I'm not concerned with my open grounds. I've been here for 7 years and never realized I had them. I'm wondering a bit though now if the open grounds actually improve my audio quality. I've heard a lot of noise can travel along the ground wire.

I was curious about the behavior where the tester changed when plugging in a PDU. I thought I would ask about it and maybe learn something. But, mainly, I'm trying to plan for my next home. It sounds like the #1 thing I can do is have an electrician wire me up with a dedicated line to my recording studio as well as my hi-fi room. I've also read that the dedicated lines should be on a separate phase as major appliances and GFCI outlets. I might not have too much control over that, though. But, I do plan on going with dedicated lines, and possibly isolated grounds as well.

I suggest you move your concerns to something else - the mains supply is almost certainly not going to affect audio quality - unless you've got massive noise coming up it, which your system can't cope with (which is extremely unlikely).

 

[Dr_Doggy]

In electrical, there are 2 grounds:
one is the neutral which is the one your aware of, which is the circuit ground, it runs down a wire back to the pannel.
The other is the chasis ground, which is the third prong on the plug and a wire from it on the inside usually bare copper or green, this wire also runs from the breaker pannel, but it runs to each junction box causing grounding in each of your electrical plates.

this is like a backup ground, so that if there is a damage to a device that causes the hot wire to put voltage on the chasis, it will cause a short circuit and trip the breaker instead of keeping the chasis of your toaster live till you pick it up.

 

[PrinceOfAnarchy]

I suggest you move your concerns to something else - the mains supply is almost certainly not going to affect audio quality - unless you've got massive noise coming up it, which your system can't cope with (which is extremely unlikely).

It does seem like a bit of a waste of time rabbit hole. However, on top of my music studio, I might look into setting up a hi-fi listening area as well. I will be taking your advice and trying to shift my focus elsewhere. But, the one thing that's been fairly consistent in my research has been the concept of dedicated 20 amp circuits with 10 gauge wire. Audiophiles do seem to chase a lot of snake oil and spend money on ridiculous things. But, generally on internet forums there is always someone calling out the BS. There is generally consensus on the dedicated 20A lines. There is a lot of disagreement on how many circuits you need, types of wire, isolated grounds, etc. But, there's general agreement on the dedicated line to reduce noise. They say it's one of the most impactful upgrades you can make. This is a pretty inexpensive thing to have an electrician take care of, so I will probably do it. I might buy one of the noise meters to measure the actual noise --> https://www.amazon.com/gp/product/B01MEFVYQD/ref=ox_sc_act_title_23?smid=A3IN8OGD15IG0Q&psc=1

Regarding my original realization that my rental house has many open ground receptacles, that's definitely something I would want to fix mainly for safety. Perhaps they are GFCI protected. I really don't know. They are not labeled as such. But, even if they were, I would still want them grounded. But, rather than worry about fixing them, my plan is to move out of this house. This is also why I'm researching the electrical setups for audio, since I could address that before I move in to my new location - would be easiest then.

 

[PrinceOfAnarchy]

In electrical, there are 2 grounds:
one is the neutral which is the one your aware of, which is the circuit ground, it runs down a wire back to the pannel.
The other is the chasis ground, which is the third prong on the plug and a wire from it on the inside usually bare copper or green, this wire also runs from the breaker pannel, but it runs to each junction box causing grounding in each of your electrical plates.

this is like a backup ground, so that if there is a damage to a device that causes the hot wire to put voltage on the chasis, it will cause a short circuit and trip the breaker instead of keeping the chasis of your toaster live till you pick it up.

I've learned about the neutral as the grounded conductor... bonded to the ground at the panel. I've learned about the equipment grounding conductor on the third prong and clearing faults if the device gets energized it flows through the EGC to trip the breaker.

I've gotten a little confused regarding signal ground and chassis ground. I've read sometimes there's a "floating neutral" and the signal is not tied to chassis. Or when the signal is tied to chassis there can be ground loops. Why wouldn't the devices always float the neutral? I guess in these cases sometimes the potential to ground is different between devices, so people bond the different devices together such as putting a wire on an audio input and attaching to a lug on a pre amp.

I've also got confused regarding the role of isolation transformers. If an isolation transformer is put into the power line, what does that do regarding the EGC? It sounds it decouples the power source from the destination, which I guess can eliminate noise but if the device were to have a loose wire fault it would still trip the breaker? I'm assuming the isolation transformer doesn't break the ability to clear a fault - that doesn't seem like it would be up to code if it didn't.

I appreciate the responses. I'm gaining a lot of respect for electricians. I'm just trying to gain some basic understanding on how things work in relation to powering my home and also audio quality.

 

[rjenkinsgb]

I might buy one of the noise meters to measure the actual noise -->

That's another item in the "Snake oil" category, and the results would be totally meaningless.

It even attempts some typical panic-mongering nonsense in the description:

It radiates potentially harmful electromagnetic fields into homes, schools, businesses, and other settings.

Just get the outlet earths (grounds) sorted out.

As long as all your power wiring is properly installed and outlets grounded, which exact one you use for audio is totally irrelevant.


I could go on for days about the nonsense claims of audiophiles, but suffice to say any normal, decent audio gear by any of the classic big-name makers (Sony, Technics etc.) with normal power and normal audio cables connecting everything together should produce excellent audio with noise and distortion below human perception, when fed from a suitable source.

If you are considering playing "Vinyl" you do not need a high end system as the disc surface noise is only around 60-70db below the peak level, vs. roughly 100db down for CD audio and rather more for newer digital formats such as Blu-Ray audio.

 

[Nigel Goodwin]

But, the one thing that's been fairly consistent in my research has been the concept of dedicated 20 amp circuits with 10 gauge wire. Audiophiles do seem to chase a lot of snake oil and spend money on ridiculous things. But, generally on internet forums there is always someone calling out the BS. There is generally consensus on the dedicated 20A lines. There is a lot of disagreement on how many circuits you need, types of wire, isolated grounds, etc. But, there's general agreement on the dedicated line to reduce noise.

Just more BS - but feel free if it makes you happy, you won't hear any difference - but you might imagine you do (placebo effect).

 

[PrinceOfAnarchy]

That's another item in the "Snake oil" category, and the results would be totally meaningless.

It even attempts some typical panic-mongering nonsense in the description:


Just get the outlet earths (grounds) sorted out.

As long as all your power wiring is properly installed and outlets grounded, which exact one you use for audio is totally irrelevant.


I could go on for days about the nonsense claims of audiophiles, but suffice to say any normal, decent audio gear by any of the classic big-name makers (Sony, Technics etc.) with normal power and normal audio cables connecting everything together should produce excellent audio with noise and distortion below human perception, when fed from a suitable source.

If you are considering playing "Vinyl" you do not need a high end system as the disc surface noise is only around 60-70db below the peak level, vs. roughly 100db down for CD audio and rather more for newer digital formats such as Blu-Ray audio.

The other claim of the audiophiles is that with regular gear the noise is less of an issue, but with their $100,000 systems it matters. I sometimes also here from skeptics or realists that in fact sometimes the audiophile gizmos will indeed change the sound, but the improvement is subjective. I'm guessing some of the gear probably does change the sound to some extent.

Right now I'm just gathering information, and it is interesting to learn about power regenerators, isolation transformers, grounding boxes, etc. It does sound like there are some real-world applications such as sensitive measurement devices. Also, even within the audiophile community there is no consensus on anything, so you can read through 20 page forum threads debating stuff. The only thing I did find that was consistent at all was the concept of running dedicated lines as well as trying to keep the audio circuits separate from the circuits running refrigerator, dryer, and GFCI outlets.

More outlets in a home is generally preferable, so my thought was might as well have an electrician run a couple dedicated 20A lines. I agree with you, and I have read others say the same thing though - you might not hear any difference. But, obviously there would be no harm, and it couldn't make anything worse, and it's not a very expensive thing to do. My plan would not be to use any fancy wiring, just go with 10 gauge Romex. I'm not planning to use any additional "power conditioning" transformers, regenerators, or anything like that. At this point I don't have any hi-fi equipment whatsoever. I just have my studio monitors and interfaces. But, I think I would like a room with no TV and a set of loudspeakers and amps as a place to relax and listen to music. I do see some of the craziness in the audiophile community, but at the same time I'm sure they have some systems that sound pretty great. So, I'm trying to separate the real information from the BS. I probably will look to incorporate vinyl. I don't think it sounds any better than digital, but I love the form factor. I'll probably look for a combo setup with a turntable but then some way to just stick a USB stick in and press play also. (I won't want to have to hook in a phone or computer)

Depending on where I move, I might need the extra outlets anyway. I know in my current home I'm running some extension cords to make up for outlets not being where I want them - in my research I've learned that's not a great practice either. But, my conclusion was that it's probably fine as long as you're not overloading the capacity of the cord even though many people will tell you the cords are only for temporary use.

I have always just been focused on my music studio and overall been quite happy with it. I have never noticed any issues with noise. I never considered anything other than plugging into the wall with a basic surge protector used primarily to gain extra outlets in proximity to my gear. I've also had the open ground outlets for 7 years and only recently tested them with a cheap outlet tester to discover the "problem".

What's confusing to me, though, is the concept of chassis ground vs. signal ground. I do have rackmount gear enclosed in metal that uses 3-prong plugs. So, I'm assuming these would make use of the safety ground and potentially could become energized if a short occurred. But, I guess some gear "floats the ground" and is not connected to earth ground. I guess this is not dangerous if the enclosure is plastic or maybe if the device is low voltage. This part has been confusing, so if someone here can clarify what all this floating ground business is all about I would appreciate that.

Regarding my 3-prong devices on open grounds, it's audio gear, not motorized stuff, so probably low risk. Still, like you are suggesting, my preference would be to get the grounding sorted out. My understanding is also that the grounding can help with protecting the gear to some extent. But again, 7 years and my equipment is still running great. I also read some conflicting information on whether or not the grounding was necessary for surge protection. My conclusion after research was that the surge protectors will work even when ungrounded whether the MOV type or the series mode type. (I have MOV type, but might upgrade to the non sacrificial series mode type like Surgex, ZeroSurge, Brickwall) That seems like it would be a decent upgrade.

Again, thanks for helping me to learn. I've been going all over the internet. It's nice to be able to ask some direct questions and get direct answers.

 

[PrinceOfAnarchy]

Just more BS - but feel free if it makes you happy, you won't hear any difference - but you might imagine you do (placebo effect).

I don't even own any hi-fi equipment right now. Assuming I purchase a setup and the room has outlets in the location I want, then perhaps I will start out with the existing circuit. That way I can try before and after. Based on testimonials it seems as if results can vary, which could be based on the existing noise and interference, the sensitivity of the equipment, and like you say the placebo effect. But, overall, the dedicated line is recommended even by folks that are against the use of line conditioning. They agree to go straight to the wall, but they claim the dedicated line makes a big difference. It's a cheap enough upgrade, so I would probably give it a go. But, now I'm thinking rather than prewire the new home I will do it after the fact. That way I can hear for myself if I threw my money away or not! Thanks for sharing your opinion on the matter. I really appreciate it.

 

[Nigel Goodwin]

The other claim of the audiophiles is that with regular gear the noise is less of an issue, but with their $100,000 systems it matters. I sometimes also here from skeptics or realists that in fact sometimes the audiophile gizmos will indeed change the sound, but the improvement is subjective.

Even more snake oil

Do what makes you happy - it will almost certainly not make the slightest bit of difference - but the poor quality of American electrical infrastructure doesn't help.

Essentially, in the 'civilised' world there are two types of appliances - Class I (earthed, three pin mains lead) and Class II (non earthed, two pin mains lead). Class II 'may' have plastic casing, it may have metal casing - it makes no difference, in either case it's double-insulated.

In the UK ALL sockets are earthed, and all mains plugs are fused, and the sockets are mostly connected in a ring, usually a separate ring for each floor. So each socket is fed twice, from either side of the ring.

 

[PrinceOfAnarchy]

Even more snake oil

Do what makes you happy - it will almost certainly not make the slightest bit of difference - but the poor quality of American electrical infrastructure doesn't help.

Essentially, in the 'civilised' world there are two types of appliances - Class I (earthed, three pin mains lead) and Class II (non earthed, two pin mains lead). Class II 'may' have plastic casing, it may have metal casing - it makes no difference, in either case it's double-insulated.

In the UK ALL sockets are earthed, and all mains plugs are fused, and the sockets are mostly connected in a ring, usually a separate ring for each floor. So each socket is fed twice, from either side of the ring.

Thanks Nigel. It's my understanding the 3 prong is a primarily a safety feature but also can be a place for leakage current. Can you help me understand leakage current? Also, am I correct that surge protectors do not generally use the ground pin to work?

Also, what is "floating ground"? Would I be correct in assuming that all 3 prong devices are earth grounded while the two prong devices and power adapter devices like phones and computers are floating ground? I have also heard the term "signal ground", which I'm understanding to be the 0V reference for a device circuit. I'm assuming signal ground is the same as earth ground for the 3 prong devices. The other term is "chassis ground" which I'm understanding to also be pretty much be the same thing as earth ground for the Class I devices.

I have been researching a lot, and these concepts are still not totally clear for me. Maybe I'm getting closer, but still a bit confused. Perhaps I don't really need to understand them if I'm not going to be building or repairing electronics and all I really need for audio is what I've always done - just buy gear and plug it in, but since I started learning about this stuff I have felt so confused and want to gain a basic understanding before I move on.

I think I mostly get the basics of circuits, resistance, current, and power. But the signal ground, earth ground, chassis ground, floating ground concepts are still escaping me a bit even after lots of research - it's been humbling and making me feel dumb even though I am typically able to understand complex things. It's interesting though. So, I will probably continue to dabble with learning the concepts. I'm not sure how much I want to do electrical hobbying though, as it seems like a dangerous hobby unless you really know what you're doing. Plus, the oscilliscopes and meters are not cheap. I'm still probably going to pick up a multimeter and clamp meter and maybe a few books. Let me know if you have any suggestions on resources for beginners to learn. I've just been going all over the internet.

I was just researching isolation transformers. That got me even more confused as I wasn't sure if the equipment grounding conductor extended to the secondary side of the transformer. I think I figured it out that it can be either way whether it's for a technician doing testing or being used for plugging in hospital equipment. (or audiophile equipment lol) Engineers would use it without the EGC connected to prevent shocking themselves or damaging equipment, but when used in a hospital it would be tied to the EGC to provide a ground fault current path to trip a breaker.

 

[rjenkinsgb]

Ground loops can be a genuine problem, with domestic audio gear.

A ground loop is eg. when two pieces of equipment both have grounded power cables & signal grounds internally connected to that, plus cables between them with the ground (via the cable screen).

The result is a continuous electrical connection from the outlet ground through the equipment grounds and signal cable ground/screen, back to another outlet ground - and of course the outlet grounds are connected through the building wiring, so there is an endless loop connection through everything.

That can act like a magnetic loop antenna and impose hum and noise from the power system across the signal connections.

That's why many HiFi units do not have grounded cables, so the only grounds between them are via the signal cables, avoiding the loop effect.

Just one item the overall system needs grounding for safety & to avoid "open input" hum.

Any equipment using single-ended signal interconnections (ground with a single signal wire per channel) may suffer from ground loop problems, and of course there are crazy price items & cables at $100 - $1000 or more a metre for audiophiles that will supposedly make things "better".


Professional / Studio equipment simply uses balanced line connections via XLR cables. The wanted signal is the difference between the two signal wires and ground noise is ignored as the signals are not ground-referenced, so everything can be grounded without problems.

Stage & Studio grade cabling is about $1.50 a metre for the really rugged flexible stuff for dragging around on mics or instruments, and ~$0.50 a metre for fixed cabling, which to me makes a massive joke of the whole Audiophile super-expensive magic cable concept.


On the subject of audiophiles and interconnects, Digital interconnects cannot affect the audio in any subtle way, as the adverts and reviews claim - it's totally and absolutely impossible.

Claims about those are on a par with someone claiming documents will read differently and have different characters, depending on the make of flash drive or disc they are stored on.

 

[Nigel Goodwin]

Thanks Nigel. It's my understanding the 3 prong is a primarily a safety feature but also can be a place for leakage current. Can you help me understand leakage current? Also, am I correct that surge protectors do not generally use the ground pin to work?

Three pin plugs 'can' be a safety feature, assuming it's all properly wired etc. But three pin plugs and earthing don't automatically make anything 'safer', in some circumstances it makes it more dangerous.

As to the effectiveness of so called 'surge protectors', I would imagine proper grounding would be essential to make them work as well as they can - but cheap ones are probably mostly useless anyway.

Also, what is "floating ground"? Would I be correct in assuming that all 3 prong devices are earth grounded while the two prong devices and power adapter devices like phones and computers are floating ground? I have also heard the term "signal ground", which I'm understanding to be the 0V reference for a device circuit. I'm assuming signal ground is the same as earth ground for the 3 prong devices. The other term is "chassis ground" which I'm understanding to also be pretty much be the same thing as earth ground for the Class I devices.

It's all very confusing - mostly because there's lot's of confusing and pointless terms used.

Just think class I and class II - earthed or not, that covers everything without confusion.

As for isolation transformers - again, they have their uses, but still don't make everything 'safe' - basically all they do is effectively disconnect the neutral wire from earth. So you've now got two power wires, neither of which is live or neutral.

Really you need to understand why things are done certain ways, and making it safer in one respect makes it more dangerous in another.

From a service point of view (with 50+ years experience), I spent most of it in an 'earth free environment' as far as could sensibly be done. As with most of the service trade, I wouldn't have dreaming of using an earthed oscilloscope - incredibly dangerous in a service environment. But if you don't know (and understand) why, then you're probably safer keeping it earthed.

 

[PrinceOfAnarchy]

Ground loops can be a genuine problem, with domestic audio gear.

A ground loop is eg. when two pieces of equipment both have grounded power cables & signal grounds internally connected to that, plus cables between them with the ground (via the cable screen).

The result is a continuous electrical connection from the outlet ground through the equipment grounds and signal cable ground/screen, back to another outlet ground - and of course the outlet grounds are connected through the building wiring, so there is an endless loop connection through everything.

That can act like a magnetic loop antenna and impose hum and noise from the power system across the signal connections.

That's why many HiFi units do not have grounded cables, so the only grounds between them are via the signal cables, avoiding the loop effect.

Just one item the overall system needs grounding for safety & to avoid "open input" hum.

Any equipment using single-ended signal interconnections (ground with a single signal wire per channel) may suffer from ground loop problems, and of course there are crazy price items & cables at $100 - $1000 or more a metre for audiophiles that will supposedly make things "better".


Professional / Studio equipment simply uses balanced line connections via XLR cables. The wanted signal is the difference between the two signal wires and ground noise is ignored as the signals are not ground-referenced, so everything can be grounded without problems.

Stage & Studio grade cabling is about $1.50 a metre for the really rugged flexible stuff for dragging around on mics or instruments, and ~$0.50 a metre for fixed cabling, which to me makes a massive joke of the whole Audiophile super-expensive magic cable concept.


On the subject of audiophiles and interconnects, Digital interconnects cannot affect the audio in any subtle way, as the adverts and reviews claim - it's totally and absolutely impossible.

Claims about those are on a par with someone claiming documents will read differently and have different characters, depending on the make of flash drive or disc they are stored on.

I have learned about the difference between unbalanced and balanced with the concept being to eliminate ground noise. I also recall in the past when we had DJ turntables connected to a mixer with RCA cables we had to also connect the the grounding wire to a lug on the mixer. So, I guess those RCA cables did not provide a ground link? I've read about whether shields are grounded and got a bit confused.

The ground loop issue seems complicated, but it sounds like it mostly pops up when you have multiple 3-prong devices or you've got coaxial cable in the mix. It also seems like the chances for problems are greater when you're dealing with multiple power outlets. It also sounds like balanced cables eliminate a lot of problems. But, since people do run into ground loop issues, my assumption is that many hi-fi setups use unbalanced interconnects. I'm assuming balanced vs. unbalanced is probably another fun topic like vinyl vs digital or coke vs pepsi. Out of curiosity, I just looked at the manual for my studio monitors, and it says they strongly recommend against unbalanced inputs.

I use all balanced XLR and TRS cables in my studio and DJ setups. (except for headphones) I have some studio reference monitors and then some PA style speakers and subwoofers. I have mostly always bought the Mogami gold brand, which I think is expensive, but they're nothing compared to those audiophile cables. I have no idea if the Mogami is better than other brands, but they've worked good for me. I also run everything off a single outlet, and I don't mess with surround sound or really even worry about audio quality for TV and movies, since I rarely watch them. So, I probably won't run into many issues. It's all very interesting, but I quickly get confused when it comes to understanding the ground loops.

The audiophiles certainly do swear with conviction that their cables make a difference on their hi-fi systems. They swear everything makes a difference whether power lines, power cords, interconnect cables, turntable cartridges, room dimensions, rack furniture. I've never got into that expensive hobby. But, I've dome some research on it out of curiosity. I think one of my favorite elements is just the aesthetics of their setups. Some of them are pretty mind blowing.