Understanding Grounding in Audio

[@chefsteve8381]

And people pay huge amounts of money for university to learn things like this, thanks for all the free lessons.

[@notjulesatall]

What do you mean? People pay for education where you live?

[@chefsteve8381]

@@notjulesatall In Australia yes, most people spend over $20,000 au about $15,000 us in fees over 4 years at uni payable when they start working

[@AudioScienceReview]

My pleasure. Thanks for watching and providing feedback.

[@jim586]

Please remember that this the internet. Not University. The website and this channel are only opinions and should be seen as such.

[@jim586]

@Paul Andersen That’s your opinion. 🤪

[@kuglepen64]

I love sanity Monday with Amir.

[@AudioScienceReview]

What a lovely way to put it. :) Thanks for watching.

[@johnburger6774]

This is amazing. He is the best around hands down. Clear understanding of what he is talking about with no BS. AMAZING WORK. KEEP IT UP.

[@garthhowe297]

Huh... even though I'm an Electronics Technologist by training, I never fully understood the true function of ground in a house. And now I understand why the neutral and ground are bonded in the box as well. Good video... yet again!

[@h.p.734]

This was so incredibly insightful and concise. I'd honestly have never known this had it not been for you. I'm learning so many things electrical engineering related as a byproduct of my audio hobby haha. And I LOVE it! All thanks to ASR and these videos. Thank you so much Amir for these educational videos. These myths only exist under the shroud of "marketing" and misinformation spread rapidly through all sorts of forums. The cure is in these videos and articles in ASR.

[@jblesser]

Once again I would like to thank you for your efforts in educating us regarding these very interesting and important topics!

[@AudioScienceReview]

Thank you so much for watching and commenting. These videos are tough to do in having to balance accuracy with simplicity of presentation.

[@jaymz168]

As a self-learning DIYer his papers and presentations helped me cut through all the nonsense about ground and balanced interfaces (and there's a lot of nonsense out there). If you join AES there are several presentations by Bill Whitlock that are 1-3 hours long on these subjects and you can check out previews even if you aren't a member and see if they're something you'd be interested in.

[@MrMatmulan]

Great video, I’m a Chemical engineering student, but I’m really interested in audio ( my dads hobby and also his job ) and these videos have been really helpful to get a grasp of some concepts You explanation of ground was the best one I found on KZbin, you should probably post another video explaining only the ground part of it, it would surely help a lot of people Cheers from Brasil

[@SkyhawkSteve]

Great video! I used to do a lot of electromagnetic compatibility and signal integrity work, and a lot of problems can be avoided with differential signals or isolation techniques. Many electronic engineers haven't been exposed to these issues and get into trouble. I congratulate you for making the effort to explain this subject to non-technical folks!

[@johnsmith1474]

I appreciate your unequivocal insistence on your points, it's refreshing. Nice and clear, on a matter that is a building block for hifi lovers. Good work thanks. PS - Steve Audiophiliac Guttenberg (love the man) just tried to promote a brand of fancy power cord. I posted that I'd like to see the electrical REASON for what he described as better sound. I'll search your vids instead where there is likely some info, and carry on watching Steve for his hip character (and shirt collection).

[@Sweet-Vermouth]

I've heard so much non-sense from Steve that I can't trust a thing he says. As an electronics engineer who has worked on signal processing, it is painfully obvious to me that he doesn't know what he is talking about.

[@thatchinaboi1]

@@Sweet-Vermouth As an audio engineer, I don't trust what Steve has to say based on many of his claims. For instance, he claims audiophile speakers outperform studio monitors. 😂

[@milo4160]

15 minutes listening, it was so easy to understand when properly explained!!!! Thx. By the way, i am so fed up with snake oil sellers.

[@teashea1]

It is nice to have such an articulate, intelligent presentation.

[@sujayks]

Thanks Amir! You have a knack of lucidly explaining these things. Really enjoyed listening. Keep it up

[@sebdhaese]

In Belgium hot and neutral first go through a differential breaker, which measures leakage and breaks when there is difference of 300mA (30mA for wet rooms), then both go through a double breaker that measures the output and breaks when the output is to high. The grounds just go to ground.

[@AudioScienceReview]

Good to know. Here we call that GFCI and is only mandated for potentially wet areas like kitchen, bathroom, garage, etc. But yes, that system doesn't require safety ground to operate.

[@Sweet-Vermouth]

@@gherbent what the comment says is, Belgium uses a separate breaker to detect leakage instead of using the overflow protection breaker. That seems relevant to the discussion especially for belgians who wonder what happens in their house when they realize their wiring is different. The ground connection actually goes to ground instead of tripping the overflow protection breaker in case of a live cable touching the chassis.

[@gioponti6359]

I think that is EU standard - or continental European standard.

[@albertolima4581]

Hello, are you sure regular zones use 300mA ??? this can block your heart!!! in europe regular zones in domestical use are 30mA not 300!!!

[@sebdhaese]

@@albertolima4581 Yes, I am sure. I do electricity as a bit of a side job. 300mA is the main safety required, so a 300mA breaker goes right behind the main connection. 30mA is only required for wet rooms (bathroom) and outside, but for extra safety I do usually put most outlets and lighting behind a 30mA breaker as well, even if I don't have to.

[@veryDave]

Just wanted to say a big thank you for all of the in-depth reviews and educational material, you're an absolute hero.

[@jim586]

If you want the very best sound quality from your HiFi, Amir is not your hero. If you want to buy basic HiFi and spend or save your money then maybe he is.

[@kkrobertson1]

Mr. Hamare (my apology if I misspell your name) your explanation as to how the AC grounds in our homes work is spot on. However, If someone were to run an individual ground to their Audio Equipment they will certainly reduce the noise (which is VERY DANGEROUS and illegal for all the reason you point out) making a huge difference in the sound quality of that system that is both noticeable and measurable! I will explain; As an RF Technician we use power supplies that has both an earth and floating ground. Why? When your doing testing on a circuit and you want the most accurate measurement. It's best to use the floating ground of the power supply rather than the earth ground; because if you have other test equipment running at the time your testing. They can interfere with your measurements if your connected to an earth ground because other equipment generates their own noise and is also connected to the same AC earth ground which increase the noise floor on your test circuit as well as their equipment. So by having an earth ground that is independent (which is illegal) of the house ground. It will isolate your audio system from the rest of your home devises that is connected to that ground. Thus reducing your noise floor. With that said, some audiophiles run a dedicated AC line just for their audio system.This will work only if you are not sharing out side line power with anyone else. If you are it will not make a different if you're running a separate ac line in your home because you will still pick up noise from your neighbor on the AC ground to the transformer you both are sharing. This is why some people are spending money to run separate AC/Ground lines or spending thousands of dollars on power plants for their systems. It does make a noticeable difference and some cases a HUGH difference! The cheapest fix for this is to purchase a DC blocker which your AC power cord will attach to it and your audio equipment will attach to the blocker. But.... before you go looking for a DC blocker, Get an ohm meter or a broadband EMF meter to see how much DC noise (if any) is on your AC line/out let. Sometimes its not the AC line that's the problem. Its the WI-FI in your home that is interfering with your sound because your wires are not properly shielded against RF signals in the 2.4-5.4 GHz range.

[@JoyRaptor]

Such good info!

[@NikolaiBeier]

+1 to the material made by Bill Whitlock!

[@americanidle1277]

Amir I appreciate the video and to a large extent agree but I'd like to explain some situations that seem to be exceptions. Over the last 6 years I have been working in an Aerospace Testing Lab as an Engineering Calibration Technician and it is my responsibility to Calibrate everything and minimize noise contribution to all analog signals since the margin of error is small considering the safety requirements of the industry. Resolution needs to be high and accuracy/repeatability are to paramount. We use hundreds of thermocouples which are simple temperature sensors/transducers that convert heat energy to "electro motive force" or "voltage". Unfortunately thermocouples operate at microvolt and millivolt levels and even worse are analog so they are just completely susceptible to noise caused by sources of EMI/RFI. Since the voltage is referenced/converted to temperature, any noise is seen as temperature fluctuations on the data acquisition system whether the temp fluctuation is real or not. A couple more things to know about thermocouples, they are DC devices and polarity reverses somewhere around room temp or 70°F. The thermocouples are hooked to devices called "recorders" which are actually just receivers with many inputs and an analog to digital converter. As far as I know the thermocouple circuits are not referenced to chassis ground. The recorder is connected to a data logging software system which plots temp over time on a graph. Although thermocouples are DC, they are digitally sampled a couple times per second usually with a digital notch filter centered at 60Hz to reduce mains interference. A sampling frequency of 3 to 10hz is fast enough to catch any real temperature changes (since mass can't be heated and energy cannot be transferred instantaneously) but low enough to avoid a lot of noise caused by high frequencies and oversampling. But this is still not enough for noise free data collection as noise will still contribute greatly to the signal. This is where the exceptions I mentioned before come in. We get rid of this noise by shielding the thermocouples and extension wires and shunting the current to ground. We were having this issue in one of our labs a while back where whoever wired it before had done everything wrong and broken every rule in the book. There were multiple needless connections on all extension wires, extension wires were being run in parallel next to 120V AC power mains, nothing was shielded, wires were running dozens of yards all of these increase noise. Well, I rewired the lab according to ASTM E633 which requires shields, and those shields are grounded on one end only, ideally the recorder end of the shield as this end contains all the extension wires. I even wrote some internal white papers with experimental evidence showing that when the shield isn't grounded the noise level is unchanged but when the shield is attached to a ground, the noise is virtually gone. During my experiments, the ground was being connected and disconnected in real time and the results were instant and clearly visible. Here's what I can tell you. There are several main sources of noise for thermocouples: 1) environmental EMI/RFI from nearby machines, radio stations and the sun/universe 2) Induced current of 60Hz hum from 120V AC mains coupling onto long parallel wire runs 3) heating elements within furnaces coupling noise into the nearby thermocouples as the furnace relay cycles on and off. It is completely acceptable to apply a notch filter for mains interference and a low pass filter to help with EMI but you absolutely cannot be allowed to filter furnace noise out because it is pulse modulated DC meaning it is continuously variable and only rises above the nominal, filtering and averaging are unacceptable. Maybe a servo controlled system could solve this but that's not worth the effort. This is what works. 1) minimize connections because connections cause resistance and signal loss neccesitating gain and gain always increases noise since the amount of environmental noise remains constant but since the signal is now weaker you have to apply gain to bring it back up and now you're applying a proportionate amount of gain to the environment noise which now means the environment noise has increased. 2) minimize thermocouple extension wire run length since the longer the wire the more noise it will pick up as it is acting like an antenna/receiver. This is how radio antennas work. 3) do not run thermocouple extension wire in parallel with ac mains or other sources of voltage as they will induce a current onto the thermocouple wire causing noise. If power and signal wires must cross, do so perpendicularly. 4) use twisted shielded pair when possible as the twisting makes the neg and pos lead occupay the same average position in space and helps cancel common mode noise and the shield rejects shunts noise if grounded on one end 5) ground all individual shields on one side only to the same common ground bus bar point to avoid ground loops, do not ground both sides of the shield as this can cause ground loops due to the difference in potential between the 2 points causing a circuit to form and current to flow especially if the loop is long and near sources of EMI/RFI increasing noise, shields are useless without a ground 6) take all the shielded extension wires and encase them within a larger common metal conduit shield, then ground this metal conduit on one side only to the common ground of the building this will shunt the majority of environmental noise 7) apply a 60Hz notch filter to help filter out mains carrier frequency noise and activate low pass filter to help filter out emi/rfi, even though thermocouples are DC, frequency components will still materialise as amplitude errors which isn't good and becomes noise. 8) Shield all thermocouples inside of furnaces on one end only and ground the shield to the testing machine chassis which is grounded to the building common ground. The shield is useless without a ground. Here is my theory as to what's happening. As for the extension wires they are picking up environmental emi/rfi from say a nearby electric motor, effectively acting like antennas, but when you encase the wire within a shield and then ground that shield on one side, the shield is now the antenna picking up emi diverting it away from the signal wire, shunting it to ground which is also hooked up to the motor chassis or whatever else is causing noise so you are effectively either shunting to ground like a sink or creating a massive ground loop circuit but who cares because it's isolated from the signal. This is basically how radio stations work after all, you send electromagnetic energy from a transmission tower and receive it at an antenna sometimes thousands of miles away, yes technically the earth could act as the second conductor but it doesn't need to because radio waves can travel through the vacuum of space. Also the furnace elements induce noise into the thermocouples but when you shield and ground the thermocouples that noise is shunted to ground or another big old isolated ground loop is formed due to the differential in the reference potential between the shield ground and the furnace ground, but it doesn't matter because the signal is isolated from the noise and the thermocouple is encased within the shield safe from spurious voltages. I'm sorry Amir but in my experience shields only work when they are grounded and that noise is essentially being shunted to ground. I can email proof of this, in fact I was promoted and received a significant raise due to the fact that through grounded shielding i was able eliminate almost all noise. please let me know if I'm missing something here but the noise in my system went from indicated swings of up to 50°F to 0.1°F just from adding shields.(faraday cages don't work for wires as the wires need to exit the cage which means they are not in the cage). I am not an electrical engineer and I don't know if the earth is acting like a sink or there is some radio circuit forming but grounding a shield is the only thing that actually works for solving/shunting noise. In fact signal wire and even speaker wires could very well benefit from running inside of grounded shields especially in wall wires that are near to mains wire. Tha is if you read this and please let me know what you think.

[@isettech]

Electrical noise is included in new revisions of the National Electrical Code for the USA. It is covered in grounding and bonding, and some more in isolated ground for sensitive electronics, also known as hospital ground. There are two main subjects. 1 Bonding all the metal stuff together so there is little voltage potential between pieces so people don't get hurt. This includes bonding the shower head to the drain so there is no voltage potential between them for a human conductor. This is related to safety. 2 Ground for sensitive electrical equipment is NOT a current carrying conductor. This means the big tower media server with the huge noise filtered power supply, or powerline conditioner is not plugged into the same outlet strip as the audio receivers, pre-amp, etc, but is plugged in elsewhere. If you use a power conditioner, it plugs into the wall, so any power filtered to ground has all current on the ground going back to the source, not placing current on the ground between audio components. Yes, it does mean using signal isolation devices between the media server and the audio system by using optical, or transformer isolation of digital paths, such as Ethernet, TOSLINK, MIDI, etc, or changing to a double isolated laptop for the media. Look for the double square on the laptop power supply and no ground pin. It is important that all audio signals are referenced to the same ground potential for low noise. This means no current in the ground conductor of the audio equipment power, AND no induced current or voltage into the ground conductor or audio lines between electronic components. www.electricallicenserenewal.com/Electrical-Continuing-Education-Courses/NEC-Content.php?sectionID=353.0

[@grisgriz85]

Great thanks for clarifying the idea of electrical ground and debunking the misconceptions. I wonder what then is the ground post (often seen in the back of amps with phono input) for? Also, what is Isolated Ground? Is it not something like what is described around 12:00, which is a code violation and a source of danger?

[@bennunezmusiclessons]

I am so grateful for your passion to share the technicalities on such an important subject like the dangers of a dedicated ground for your audio equipment. I'm sure your own explanation would have been sufficient. However you took the extra steps to quote another master mind, Bill Whitlock. This only adds to your credibility. Thanks to you, I now understand important grounding basics & may have been saved from injury. I saw the OPPOSITE advice from your buddy at PS audio . . . search them & "Best grounding practices for audio". Sadly, it was the opposite position of where you & Bill Whitlock properly stand on the dangers of dedicated grounding of audio equipment. I am taking your advice & NOT doing it!

[@Johnnytrades101]

I am a Red Seal Journeyman Electrician, with over 35 years in the trade, also Certified all across Canada, (interprovincial). I can not agree with you more! Very well done. Don't get me started on $1000 cables ect lol. This is not rocket science, basic, basic electrical theory. Maybe swamp land in the Sahara is an option!!!!

[@shaynakash4222]

didnt know you listen to electricity......

[@michaelbeckerman7532]

This is a terrific analysis of the problem, but there is little to no mention of how to actually go about resolving this issue. The most common problem we often hear of is someone saying something like, "When I plug my subwoofer into a power outlet in my audio room it makes a hum/buzzing noise, but when I move it and plug it into an outlet in another part of the house, I don't hear any hum/buzz at all." How does one go about fixing this problem then in their home? Do they use a noise filtering surge protector? A high-end surge protector with line conditioning like one from SurgeX or Brickwall? Something else?

[@SkyhawkSteve]

This is a reply to a year old question, but I think his solution was to used balanced signals to transmit the audio. He didn't get into the specifics, unfortunately. Perhaps there are off-the-shelf converters to go from unbalanced RCA to balanced XLR formats? Other than that... it would help to have all of the equipment connected to the same safety ground point.

[@michaelbeckerman7532]

@@SkyhawkSteve yes, the 60Hz buzz results from a difference in ground potential. If you can get everything in the system running off of the same outlet, it will all have the same ground potential and therefore no hum/buzz. That's the easy fix, if you can do it.

[@maxheadrom3088]

Sir, I do admire your work and your site is the reference I use before buying audio gear - however ... earth can be seen as a conductor. As an experiment, get a copper bar, put in completely into the earth (with nice humidity); get a lamp and connect one terminal to a live wire and the other to the cooper bar - check what happens to the lamp. Now ... adding a second earth to the system is not only illegal - it also contributes to ground loops. What the code says here in Brazil is that for sensitive equipment the ground wire should have the same gauge as the neutral and live wires. Why is that? Those systems are sensitive to ground loops so if we ground everything with good thick wires then there won't be ground loop because all devices will be at the same reference point. For very sensitive devices ground wires will have the same length to avoid having devices on different voltage potentials. Ground also helps drain EMI from cable shields. Now ... how much that appears in audio I don't know - I know when I hear it and I had ground loops that were noticeable.

[@jimbroen]

I've been using unbalanced connections for years and they've always seemed to work just fine. I recently had a problem with a DAC adding an intolerable amount of noise and thanks to your video I now know why. The live sound folks use balanced connections for everything and I've always suspected there was a good reason. The band at your local pub has one less thing to worry about when they connect all those wires with their numerous pieces of equipment.

[@torarnekvaly7753]

Thank you so much for explaining the benefits of using balanced cables! I have tried to understand this for so long time, and now finally I do. Thank you!

[@donalddluckerii3147]

Informative video. Do you have a video on how to combat excessive (audible) noise in the form of buzz or hum in an audio sytem? Also, when we A/V installers in the field encounter buzz or hum we usually blame and rectify poorly grounded Sat or Cable boxes and the problem often goes away. Any idea as to why properly grounding the incoming rg6's grounding block to the panel or the designated house ground would solve this problem?

[@AudioScienceReview]

Best techniques are using balanced audio interconnects. And deploying optical links (toslink) for digital audio when necessary. Other techniques like grounding, etc. that you mention are rarely effective.

[@Seiskid]

Well said. Safety is critical. Grounding should never be compromised because of audio reasons.

[@TAMIL-MUSIC]

Your video are so super. I seen similar level video only from audio holic. I have question.if you undersand please explain.If I take speaker ground from transformer ground for speaker ground,I hear noise in speaker but i i take from board there is no noise in speaker. They advise to take speaker ground from transformer but if I take from transformer ground it give low level noise in speakers.how to fix

[@mengshilim7364]

Please do something on equalization - parametric vs graphic etc. Thx.

[@AudioScienceReview]

I plan to talk about it in the context of room acoustics.

[@TareqASamra]

Oh alongside dsp stuff like compressor effects would be interesting.

[@FOH3663]

@@AudioScienceReview Exactly, EQ'ing is tied to the acoustic transition region... Ideally, EQ'ing should only be utilized in the minimum phase region below the room's transition frequency. Otherwise, application above the region, one's merely correcting for one specific location... creating issues elsewhere.

[@Lauren080508]

Thanks for another educational video! congrats almost 10k subscribers!

[@kangchenglu]

Amir, Thank you ! I'm suffering the RCA noise problem (When I touching RCA input of the amplifier, that will be worse from speaker). I think it's time to change my system to XLR connections.

[@julesturtur]

Great video, thanks for the effort! Do the neutral and ground wire really “join” in the return path, as shown in the picture? Wouldn’t the chassis carry electricity at all times, then?

[@shaunvickers9255]

Thanks Amir for all your informative tutorials. These are a huge benefit to the audio enthusiast community to understand how to connect your analysis and data to our purchasing decisions and listening experience. Here is my request for a tutorial: Could you explain the systemic relationship of SINAD and what SINAD and distortion levels are important in each step of the digital audio chain end to end? For example, you target 96db in DACs as a min. threshold to resolve 16 data accurately, but 50db in speaker headroom between signal and distortion. How should I think about the stack of SINAD from DAC, Amplifier, speakers and what should I target in each, and what does that mean end to end for a complete system that sounds great end to end?

[@AudioScienceReview]

SINAD includes both noise and distortion. With respect to noise, your speakers have infinite signal to noise ratio because when you don't send them anything, they are totally silent. In high performance audio devices, noise usually dominates SINAD and hence, it is useful in that regard. Outside of that, it is a sign of good engineering. If you are buying something new, might as well buy the one with less distortion at the same price as one with high distortion.

[@shaunvickers9255]

@@AudioScienceReview I believe you mentioned in posts on the forum (can't find it now) a rule of thumb of having 10db more headroom in your upstream components and wanted to learn more about that relationship. How to understand the system (DAC+amp) SINAD stack vs. the speaker distortion levels and when one or the other is the limiting factor of the system fidelity. E.G. if my speaker distortion is 1% at 86db SPL, should I worry about DAC+Amp SINAD above 86db? How do I think about the relationship between these two things?

[@flex-cx9bi]

@@AudioScienceReview Not true. You need to fully understand amplifier design and know what to measure in order to make a qualified decision. Yes, lower noise is better, but when achieving that low distortion figure at the output stage, what do you do with the input stage? When do you ever measure the performance of an bandwidth limited input stage in a amplifier with high NFB? Is it of interest? Yes, very much so, but unfortunately mostly ignored. Even by the amplifer designer too. Harmonic distortion do have a colouration of it's own depending on the configuration of the harmonic components, and you really need to know what to look for when selecting an audio component. So selecting the component with the lowest distortion at the output do not tell the full picture. It can alter the sound by promoting odd harmonics and reduce even harmonics. Check the harmonic content and distortion levels of the input stage. That says very much about how the low distortion figures at the output have been achieved. A bandwidth limited (need to in a amplifier with global negative feedback) will not be able to fully handle the harmonic content from the recording. That will create monotonicity and will not let through the full recorded signal intact and unharmed, which we need to do to get the full picture of the recording. By saying you should select the component with the lowest distortion you simplify the problem when selecting an audio component. Start looking at the harmonic distortion content of the distortion, and do that in all stages of the amplifier. Input, VAS and output stage. The task of selecting a component is much more complex than simply select by the "low distortion" mantra.

[@moonlight-kh6uz]

I still remember my professor of electromagnetism and mathematics, who said "Nobody knows what current is". Of course, he did not mean I = U / R, probably what he had in mind was a philosophy of electromagnetism. All kudos to ASR and Amir for debunking THE biggest scam in history. 1000s and 1000s of companies, selling bull for more than 70 years. All on the premise of wide-spread OCD in the population, and the concept of "discretionary" income intertwined with the "Keep Up With Joneses" paradigm. Some economist must eventually compute how much Earth resources were spent on these fictitious "products". Fat profits, fatter than anything else out there. High end audio is on par with Goebbels propaganda machine. It's huge. It's unimaginable.

[@gioponti6359]

Thanks for very interesting video! Am well aware about compensation current between devices, but what is called here balanced system has only two connectors and is thus not really a balanced ie xlr based connection, or did i get this wrong? XLR’s third contact is (signal) ground and still connects the 2 devices’ signal grounds. Also, signal ground does not necessarily mean its connected to housing and thus (power grid) ground, correct? Another point that follows on from wall outlet (15:18): it seems obvious to connect hifi devices from same wall outlet or as close as possible. My ear confirms that; there are some who prefer direct connection of a power amp to wall.. and sources and preamp to a distributor connected to different wall outlet (on same loop), i don’t, and one can hear the difference of such little things (more clarity).

[@AudioScienceReview]

You are correct that XLR has three wires with one connected to ground. Key here though is that said ground is NOT used as audio signal reference. So it doesn't matter how much ground currents you have over it. In RCA, that ground is also the audio reference which causes ground loops.

[@gioponti6359]

@@AudioScienceReview tx for info!

[@eldredgodson5750]

Great video thanks! One question. I have a nice AKAI AT-K02L tuner connected to an AKAI Amp etc, with a DIY 1/4 wave omnidirectional 75Ohm ground plane aerial mounted on the roof connected via approx 10 meters of coax cable. The manufacturers user manual set up diagrams show a ground spike connected to the aerial ground peg on the back of the tuner. I have not installed this. Basically the FM radio sounds great, receiving very strong signals from multiple transmitters. However there is a hum that is only really noticeable when amp turned up pretty loud (this hum is not there with other sources such as phono and cassette so not a function of amplifier volume). I often tune the radio to one of the weaker signals for a given station, as this seems to reduce the hum. It is possible that the stronger signals come from a direction where there are National infrastructure scale HV cables and a vast substation between transmitter and receiver. Will installing the illustrated dedicated ground spike help in the case of the aerial? Would it be better to wire the radio ground peg to the domestic earth circuit via a plug socket?

[@joereynolds6496]

I really do appreciate your video and the pushback against the insanity, that is the myth saturated hi-fi industry. I would love to see a video that address the “micro vibration” effect on solid state audio amplifiers/preamplifiers and the industry’s sale of isolation feet and their claims of “huge improvements” in soundstage, clarity and dynamics.

[@jim586]

Oh really? I take it you have not heard these products then? The internet has a peculiar reaction from us humans - mainly negative. If you don’t think cables or supports work or aid HiFi then simply don’t buy them? Why is there a glee in many commentators posts that perfectly legitimate companies are scoundrels and should be run out of town, as they’ve been found out. You don’t have to buy them, it’s a hobby! Give an engineer, a KZbin channel, a nice demeanour and a probe and for some reason he’s the new messiah. Ha If things measure the same why is it that dozens and dozens of loudspeakers (for example) have similar specifications but all sound different? Are you suggesting the you may as well buy a £100 speaker as it’s frequency response and sensitivity is the same as one costing £10,000? Nonsense.

[@philiptong4978]

@@jim586 it's the space where the speaker and you are listening in, room dimension and construction material has its own sonic characteristics

[@jim586]

@@philiptong4978 Hello, I agree. The room is incredibly important to sound quality.

[@kirillgulyaev1770]

​@@jim586 I know I am late with this reply, but FR and sensitivity measurements are a tiny snapshot of speaker performance. There is much more to measure and there are characteristics which make more sense to look upon: at least room response, directivity, compression. And yes, two speakers which measure the same (not just freq response and sensitivity) will sound the same, period.

[@deanedgx]

I wonder how this applies to the various earthing systems such as TNCS, TNS, TT?

[@arcorob]

This was amazing, I am learning (at age 62..lol) because I am dabbling in building amplifiers, Grounds had me crazy because other than the chassis ground, I kept wondering "do I need a star ground, what should I ground and what should I avoid". My circuits will all be DC (ACtoDC converter) but I have to ask, in a normal UNBALANCED system, are there any other grounds to address of just board to board and leave the only ground as the chassis ground? I need to share this video !!

[@zyghom]

EU is more on bassy side - 50Hz is lower than 60Hz in US ;-) Amir, that was super nice repetition of my school (that I finished 30y ago) but I remember from that lessons: NEVER play with the ground - it is NOT FOR FUN but to save your life - you nailed it today But I think you forgot to mention: GROUND - especially when Neutral is disconnected - makes sure, when you TOUCH the chassis that is connected to HOT (by accident) will make sure that the current will NOT drive from your body (touching the chassis) to the ground under your feet (as there will not be voltage difference or lets say potential) - that is the real reason of grounding every (almost) equipment. Also there are differential fuses/breakers in use to sense the difference between HOT and NEUTRAL wires and they disconnect if the difference of current reaches the threshold. One more thing: delete all RCA and move to XLR but FULL PATH - right? And one more: grounding (no, connecting together) the equipment in the chain i.e. turntable preamp with the amp. Many amps and many turntables have extra socket to extend the ground between them

[@nozzlepie]

I think the biggest issues is the name Earth or Ground. It makes people think they know what it does. The proper name for the the green and yellow striped cables in your wall here in the UK is Circuit Protective Conductor (CPC) and is much more true to actual use.

[@drewwilson1477]

As a child I remember many cars having ground straps dragging on the asphalt. To “cure” car sickness. Your idea of chains dragging on the ground to improve car stereo is brilliant. We will make a fortune. But the chains must be made of some exotic unubtanium. Don’t want DIY’s steeling the idea. Lol. Keep up the good work of Engineering vs BS.

[@carloschan6892]

Should shielding connect to neutral on the pre amp side?

[@MadAudiofficial]

Very interesting video👍🏽thx

[@AudioScienceReview]

My pleasure Mad. Thanks for watching and commenting.

[@MadAudiofficial]

@@AudioScienceReview i was follow u already on Audio Science Review web site, nice to see u on KZbin i really appreciate your work 👍🏽

[@scottkasper6378]

As a tradesman I know all this. I’m also a musician and audiophile. I’ve been on countless gigs where guys will say “we need to lift the ground because the pa is noisy. In 30 years I’ve never seen that work nor did I ever see how it could’ve.

[@TareqASamra]

My thx headphone amp has that buzzing/vibrating feeling whenever plugged in. I always wondered what it was.

[@puresound1856]

Is it then beneficial to use an extension chord/multi outlet and hook up all electronics to it. (if rca's is used) ? -Thanks for great videos

[@philiptong4978]

yes, because it will ensure connected equipments will have very similar ground reference, also powered by the same phase (at least for the 120-0-120 split phase system)

[@AudioScienceReview]

It is good practice but the key point is that ground differential will still exist. Indeed there are people experiencing hum and buzz even with such practices. Best to have a good system design that avoids the issue altogether.

[@puresound1856]

@@AudioScienceReview Thanks! I dont have hum etc but I did have a strange thing dusting metalic cd player with static cloath; streamer cut off playing when I touched cd player. Amp and dac/streamer were connected to wall outlets on different wall than cd player. Once I hooked them in same power outlet the problem was gone.

[@Columba_Kos]

It is interesting that you discuss the parasitic voltage that you feel on a chassis when you touch it. This should not happen nowadays with polarized plugs, but with older equipment that had non-polarized plugs, this was a quick way to determine if a device was connected properly to the AC line. That voltage disappears when the plug is properly inserted into the outlet with respect to ground.

[@martijnbos9873]

I live in Vietnam and here my house has no grounded wall sockets. All my wall sockets only have 2 pins. This results in me being mildly electrocuted everytime I touch my equipment and if I touch my headphone with my hand I hear a hum. I was thinking to housing of my amp with a ground wire to the actual ground (earth) to solve this. After this video I am not sure this will help. How can I get rid of the hum and the electric shocks in my system?

[@mauiztic]

Hi, this information makes sense in my mind up to a point, maybe you can help clear out a couple of questions. If ground serves absolutely no purpose other than safety, why is it that a guitar amplifier goes quieter from noise when connected to ground, or even by someone touching a just bit on the chassis? Also, if neutral and ground are tied up together at the rod, why don't just use neutral and connect it directly to an equipment chassis? Wouldn't that serve the same purpose and would make innecesary to have a ground wire all the way from the rod to the equipment? Thank you.

[@AudioScienceReview]

Hi impedance inputs are very susceptible to picking up ambient mains noise. So you do need to pay attention to that. But there, we are talking about signal ground. What that connection has to real earth is of no value here.

[@philiptong4978]

for the 2nd question another name for neutral is "grounded conductor" another name for the electrical ground is "grounding conductor" both are maintained at earth (where you stand on, also pushing you up) potential the difference is neutral being part of the circuit carries the return current in normal use (can be zero if it balances out by all phases) ground wire only carry fault current when a fault happens, it is a short circuit path (via ground to neutral bond) back to transformer/generator this also explains why neutral-ground only bonds at one point in a single system, typically at service entry, avoiding any section of neutral wire to carry fault current not bonding neutral to chasis also prevents non-polarized plug from energizing the chasis with mains voltage

[@BasementBerean]

So, I just had to delve into this to solve a "ground loop" that manifested itself after I swapped in a new CD player, connected to an audio only amp, after my original one failed. Suddenly there was this hum, and I used a pitch measuring app to find it was 60 Hz. Now, as part of my system I had a laptop I used for streaming, with the video running through an HDMI cable to an AV receiver (with an amplifier of course, but I used it only for picture to the TV and not sound), and the audio running from that laptop through a DAC to a different, high end stereo audio only amplifier. The hum could be stopped by unplugging the HDMI cable, the USB from the laptop to the DAC, the RCA cables from the DAC to the audio amp, the cables (DIN or RCA) from the CD player to the audio amp, or by unplugging the CD player itself from wall current, whether the CD player was powered on or not. Somehow they were all in this together! I noticed that the AV receiver had a polarized, but not grounded, plug. I decided that some residual electricity from inside the AV receiver must have been "liberated" by the new CD player to now encompass everything. I solved the problem by routing both sound and video from the laptop to the AV receiver rather than the audio amp, thus breaking the connection. Do you think I got it right?

[@andreasbmx100]

Great video - content as always . I would like to see a video or article about interconnect cables specifically RCA . Does it make sense to use microphone cable instead of coaxial cable ? I have tested both just to learn how to make a cable , but I don't see much difference 😆

[@RyougiVector]

Since the harmonics from RCA tend to be below the threshold of hearing, I think you don't need to spend money on that. There is some peace of mind thing than anything else to have XLR over RCA, like using FLACs versus mp3 320kbps files. But RCA and mp3 320kbps files are good enough in so many cases anyway.

[@andreasbmx100]

@@RyougiVector Thanks , that was helpful. At least I learned how to make my own cables 😄

[@ronniefranks4351]

This presentation was very interesting. Perhaps you can help with a hum issue I have. I built two mono single-ended triode amplifiers and they sound great. However, I have a hum issue that’s not terrible but I’d like to get rid of it nonetheless. With the RCA interconnect between my preamplifier and amplifier unplugged, I have no hum at all. With my preamplifier connected, I have hum at the speaker, even with nothing but power connected to the preamplifier. All components are plugged in to the same AC outlet. I get the same result when I replace the preamplifier with a CD player. With two components plugged in to the same AC outlet, I fail to see how there can be a difference in potential between two components with nothing plugged in to either component but a single RCA cable. Can you possibly point me in a direction to further pursue a resolution? I’m out of ideas and would greatly appreciate any guidance you might provide.

[@philiptong4978]

the noise could be external beyond your amps and source connected to the power grid such as rf transmitter, switching power supply or other device, unplug one suspect at a time and listen or measure, hopefully the culprit is within your demarcation

[@fourthlaxer4557]

This is a great vid HOWEVER there is no solution mentioned as to how to remove hum when connecting RCA's from amp to subs! Subs are being powered by 2 sub outputs @ rear of yamaha receiver. All a/c plugs are 3 pin w/ common ground @ power strip. No balanced connectors are available. HELP!!!

[@peterchen4694]

Off the audio topics, I installed a new solar system in my house, the system is connected to my main electrical panel, the city inspector came by and failed the installation because they requested two grounding rods （6 feet into the ground) and they have to be six feet apart. I am wondering about the requirements, my sound system has two outlets directly connected to the System the main electrical panels (20 amps each). Do the grounding affect my system? Thanks for the educational information, really appreciate your efforts!

[@philiptong4978]

it make sense to physically separate ground rods apart to minimize the raised ground potential affecting each other when lightning strikes, to maintain identical 0V reference, they may also request the gnd rods are bonded together with certain wire gauage

[@welderfixer]

Amir, thank you for telling the truth. So many people are hurt or killed with 120vac because of open neutrals, ground faults and not wiring to NEMA code. The thought so many people have about electricity being a benign energy source as just foolish. I work with system voltages up to 1000Vdc and 3500Vac @ 1Khz. Yes, some days are more shocking than others. I am lucky to have survived any of those shocks. Also, electrical systems are NOT maintenance free. Circuits must be tested and screw connections tightened every so often. Especially if there is any aluminum wiring.

[@AudioScienceReview]

My pleasure and well said. I too have had my share of electrical shocks and they are no fun. Always relieved to survive them. It is amazing how many audiophiles like to ignore safety and chase inappropriate grounding that doesn't improve audio anyway. I have written what I have explained in this video countless times but these people don't listen.

[@welderfixer]

@@AudioScienceReview Well ya know Uncle Bubba's neighbor Jim knows more about everything than guys like yourself thats been in the biz for fourty years. Don't feel lonely, I get the same thing here with welding and welding equipment.

[@philiptong4978]

it is ok to use multiple ground rods physically spaced apart, the dangerous part is failing to establish the short circuit path for fault current going back to neutral-ground bond at service entrance

[@StewartMarkley]

Very nice job Amir. One question, given the typically low leakage currents in audio equipment, and that generally people connect all of their audio equipment to a single outlet and power strip/surge suppressor/conditioner device so that the resistance of the ground between components is very low, it is pretty hard to imagine how a there would be enough difference in ground potentials to cause a noticeable hum in an audio system from leakages to the ground connection. So balanced connections are really only advantageous to counter EMI and not generally power line hum, right?

[@itoaa]

Real good point about safety. Do not do unsafe things just if they sounds better!

[@quananginh9446]

I'm from Vietnam where we don't have the third ground pin. Once I bought a Behringer mixer which has a 3-pin power connector from US. The mixer slightly electrocutes me when I touch its chassis. I used an electric wire to connect the ground pin of the power connector to the floor and the problem's gone. So the floor must be drawing some current from the chassis. Someone explain this please?

[@johnwright8814]

Not audio, but it is science. There was a company with two ovens, one was internally wired for 115vac, the other for 230vac. When a temperature controller failed, they couldn't be simply swapped between them, because the transformer primaries were wired in series for one and parallel for the other. We now have universal-input switching supplies that would work in either oven and be more convenient when one should fail. I fitted one in the space left after the removal of the transformer and tried it on the oven. Random numbers on the temperature readout was not good. Realizing that this would be interference caused by the switching nature of the new supply, I connected a 100nF capacitor between the 0v power supply output and chassis ground. Stable operation resumed.

[@mardak2871]

I would very much like an explanation of the 220V ground setup. is it the same as North America?

[@zoltangz]

Amir, your videos are extremely well made, informative and accurate... but is there anything you could possibly do about the very annoying, frequent use of your "aahhs" during your presentations?! Thank you.

[@AudioScienceReview]

It is something I need to train myself to do better. Sorry about that.

[@Chuek-WaiTai]

Very informative! Thank you! Some amp hav no ground line, e.g. Yamaha. What is the tricky they did?

[@philiptong4978]

kzbin.info/www/bejne/hXTdk3etq8mgntU

[@chrisko3602]

@@philiptong4978 No, Yamaha Amps made with metal.

[@chrisko3602]

Because these Japanese amp makers think connecting chassis's ground to GRN line is a bad idea. They usually leaves a GRN screw at somewhere of chassis which can be used for customized grounding. Yes, these makers DO NOT totally agree with Amir's idea, vice versa.

[@chrisko3602]

​@Jon Beck Good question, the GND line which connect to earth means a lot for electronic safety, in some cities, have no GND line in the power infrastructure, citizens need to do the safety like use isolation transformer by their own. However we can say that 2 pin power system can still work, with higher risk. Amir has introduced the concept of chassis ground loop, so you can imagine that if we we use 3 pin plug for all metal chassis electricity, all the chassis will be connected through the GRN, and the ground noise propagate everywhere. In the above case, if one of your gear (including refrigerator, washing machine with 3 pin plug) failed to against the chassis ground noise (the threshold becomes low), the noise starts affecting the sound. This is a kind of system risk (for sound). So it became a - "which risk you wanna take to avoid another risk" game.

[@konstantinost3185]

In Greece latest Mains Regulation requires an Overflow/Leakage Breaker and Neutral isn't connected to Ground. Mains Ground is only connected to the Earth Rod.

[@stefandenic7144]

Thank you for your wonderful presentation!

[@SlickBlackCadillac]

I needed this video. Great timing!!! I have QSC powered speakers which have a very audible ground loop when I use RCA unbalanced cables. It disappears when I use XLR balanced cables. It has been driving me crazy trying to understand why as there is so much misinformation out there that says XLR does not solve ground loop issues in audio. Your video illustrates that while XLR does not solve the ground loop, it does remove the sound of the ground loop from the signal path. THANK YOU!

[@dansantoso48]

I made my own diy ground box for my amp and dsp with tormaline, quart, etc and an antenma inside and it has subttle difference to give better details. Interesting. I think many in audio cant be measured and it has some benefit. Otherwise if it is 100% bogus why some people still believe it makes some difference. You need to measure then do a group abx test to make sure.

[@ShareHobby]

The presentation has the original ground in the outlet disconnected, which violates code. What if you were to leave that connection untouched on outlet and add a supplementary grounding rod? Electricity always searches the shortest and least resistance path to earth ground is what I’ve come to understand.

[@eddiejennings5262]

Thank you, sir. Great presentation and references!

[@dennisw4654]

A while back I experienced a hum while playing my TT while connected to an integrated amp (class D) and utilizing the TT grounding wire and terminal on the back of the amp. To correct the problem I built an additional ground wire to directly connect the ground terminal of the amp to the outlet ground. It worked well but was it kosher?

[@AudioScienceReview]

Unless I am misunderstanding what you are saying that is fine.

[@taylorsharp5928]

Great explanation! How does EMI / RFI tie into the discussion of grounding? Wouldn't the earth ground be effective for minimizing effects from these sources of noise?

[@isettech]

RFI/EMI is where a wire becomes an antenna and picks up induced voltage and current. The solutions for this can be complicated, but in general is physical separation from the noise generator, shielding from the noise source, and make the receiving wire much shorter. In general avoid long wires, put the equipment in a metal enclosure, such as an equipment rack for shielding, and locate away from the transmitter source, which may be a TV, blender, or other motor with VFD or brushes in the area.

[@gherbent]

If the system is correctly designed you do not need grounding, grounding is also another antenna, but unfortunately because of most of the PSU designs, we need to connect the components of the system to the earth.

[@isettech]

@@gherbent True, however bonding can reduce the voltage differential between components. In a home stereo, this is most often completed by plugging all components with a grounding plug into the same outlet strip.

[@gherbent]

@@isettech Yes, I know. just I am not a native English speaker. I will remember to use this notion of 'bonding'.

[@filippiasec]

Respect for your vids!!!!!

[@floydkannan]

In India the line is called phase and the input voltage is 220 volts. Three 220 Volt phases spits from the secondary side of the transformer along with a neutral which acts as the return path. The neutral is shunted at the mains transformer. Every house will have its isolated earth (ground). I case of a short, the current will pass through the isolated earth as it is the shortest path and trip the mains. The neutral and earth as you have shown in your diagram in the video are never connected in our circuits, else the purpose is defeated.

[@jim586]

The two systems that I’ve tried in the UK, are both legal, as they work as additional earth. You do not disconnect the electrical circuit from the safety ground! As you say, illegal. This is what we agree on. What we don’t agree on is I have had fantastic results using these devices and yes during blind testing situations. Not just me but family members. These are in line devices not the “box on the shelf) type. Cheers

[@carloscervantes836]

I see there are many audio isolators for cars that say they fix noise issues. I noticed an mpow version is very light and much smaller than it was before, not sure what they changed to make it smaller and lighter. Have you measured any of these car solutions and taken them apart to see how they are designed?

[@davidketley5359]

A ground loop hum can be only reduced or eliminated by inserting a 1 to 1 transformer in the signal path like the ART DTI Dual Transformer & Ground Loop Isolator?

[@SolarisUK]

What about hum destroyers like the Behringer HD400? I have a demon x4500h with preout RCA to my Musicial fidelity m2si and if i put my ear to the speaker when nothing is playing i can hear noise through the speak will the HD400 do anything for the system to eliminate this ?

[@beardedgaming1337]

current NEC code in my state is to have two grounding rods, minimum of 10' apart but no more than 20' apart. its for lightning strikes to have multiple options to shunt to ground. they require this with any dedicated structure. so a detached garage would need two, and the house itself would need two.

[@Daminlk]

@Amir, here is an idea for a video - someone at Hegel last week was saying how something can sound different (his example was bass definition) but in measurements looks the same. Have you experienced anything like this? E.g. Two amps/ speakers that measure the same but sound different?

[@AudioScienceReview]

Oh I "experience" it all the time. Problem is, when I don't know what it is being changed, that improvement disappears.

[@Sweet-Vermouth]

We have got to the point where we understand sound and electronics so well that we can quantify everything about it. The pressure amplitude, the frequency, the phase, the exact frequencies that make up a sound, basically everything. Our ears and brain basically measure sound to make sense of it. To claim that there is something un measurable about simple pressure waves is ridiculous.

[@Daminlk]

@@Sweet-Vermouth I don't know what measurement is used for explaining how a pair of speakers can have a bigger soundstage with pinpoint imaging and even a 3d soundstage. Vs a pair that makes everything sound together in a narrow spot

[@Sweet-Vermouth]

@@Daminlk that's actually pretty simple. The sense of space in music is created in two ways - 1. Vary the volume of the same sound such that it is louder on one speaker than the other. This is useful for creating larger differences in distance and direction. 2. Vary the phase of the sound - the phase of the sound coming from one speaker is slightly different than the other. This replicates the way we hear sounds everyday. The sound hits one ear before the other and even if the time difference between the two ears is imperceptible, our brain uses the phase difference to figure out which direction the sound came from. This is more useful for finer pin pointing of the source. If your speaker and amp are well positioned, and have consistent phase response, then you can say that it recreates the soundstage well.

[@Daminlk]

@@Sweet-Vermouth those are mixing and recording attributes. Two sets of speakers positioned in the optimal way playing the same track can sound significantly different.

[@alanwaterfall7002]

A good reminder video of the importance of the safety earth and why not to mess with it. I borrowed and tried an Entreq ground box on my system, the difference I heard was definitely in my head, it was a small difference, but I definitely got it in my head. My head told me it was a good difference. If I were to choose to buy one, and my head was pleased and happy, why would you want to spoil my happy experience?

[@AudioScienceReview]

You don't need me to spoil it. Since the difference is not real, it will dissipate by itself. Hence the reason some audiophiles keep chasing this and that tweak.

[@Michiganman08]

I've watched this great video twice. I did this very mistake installing my dedicated line, which I will disconnect the extra ground, which I connected to a cold water pipe. I've read many years ago about actually lifting the ground from all 3 pin plugs. Then use a cheater plug, which the neutral blade is filed down some, to allow us to flip the plug both ways. One way may, should, or does "sound ' better. Has to do with Eddy currents. I'm not an electrician. I have done this on a pre amp, and amplifier. Sometimes no difference I could discern. Sometimes yes, I thought one way sounded better. This was checked with a multi tester set to AC volts, everything disconnected from said component. Positive test lead is touched to the some metal on the component, the negative probe placed into the 3rd middle hole in the wall receptacle. One plug orientation will have a higher or lower reading. This is called as I understand it, measuring eddy currents. Amir I would love your comments. Thank you.

[@ChazzDerby]

Thank you werrt much for this video. As an electronics technician and a member of a local Hi-Fi comunity. I have seen many make their own ground an even a seperate phase in their house to the Hi-Fi beliving it gives at more pure ac and better sound in their hi-fi. So love to be able to show the these videoes, although some still don´t belive in i´t. One idea for you, for a video is. In denmark ve have 230Volts in the mains, and are able to reverse the phase and zere on the mains. I´t is not required by law to have a ground pin on your plug. So there are people who are using money on equipment to measure the phanse on their mains to make sure alle are plugget in the same. Does this give any meaning at all to you? Kind Regards Kenni.

[@philiptong4978]

noise in ac power depends on connected equipment on the grid (your physical power distribution region - heavy industry? Just like electricity power generation, required load fluctuates, it can depend on season, public holiday, day of week, office hour time of day) your neighbour, your refrigerator ... and finally whether power supply used by your audio equipment is able to handle it

[@prateeksamuel8603]

Greeting Sir Amir. 🙂🙂🙂 Maybe someday we can standardise differential audio signal using the rca connectors like the khadas tone2 pro. Those connectors look really good and high quality aswell. Imagine two of those on every audio equipment. 🙌🙌🙌🙌

[@AudioScienceReview]

Ah, finally someone addresses me with the proper title! :D The Khadas RCA connectors are very neat innovation. The issue I hear about them is that they are expensive so others are not adopting it. For others not knowing what we are talking about, I covered it in my Tone2 Pro review: www.audiosciencereview.com/forum/index.php?threads/khadas-tone2-pro-review-dac-amp.20684/

[@exarkunn69]

Wow! I never knew this and it explains so much now. Thank you for the lesson!

[@haroldbarber9828]

Hello, as a live sound engineer I´ve been searching for "the truth" about electric connection and grounding of sound systems and your video was very enlightening . Still I have some doubts due to practical experience, here is one question: Your explanation of a circuit using a battery an a light bulb is clear BUT what happens if instead of the positive of a battery you use the hot terminal of a 120v AC receptacle and instead of the little bulb you use those voltage detector screwdriver and the bulb turns on, how does the circuit complete?

[@philiptong4978]

I believe you (grounded at ~0V) have to touch (or intentionally ground) the screwdriver opposite end for the bulb to turn on when using it

[@haroldbarber9828]

@@philiptong4978 But I`m on my rubber Nike shoes so I´m not "grounded", I even tried it on my Nike shoes standing on a plastic stool and still works. My point really is not about this case, I was going to the point that as a live Sound engineer (live shows) I have faced cases in which I don`t have a grounded system (I live in Venezuela) and if I have a ground Hum and I "ground" my system with an independent rod the hum will disappear so it looks like the Earth does absorb that noise (voltage) the same way as our body mass works as a ground for the screwdriver

[@haroldbarber9828]

@@philiptong4978 But I`m on my rubber Nike shoes so I´m not "grounded", I even tried it on my Nike shoes standing on a plastic stool and still works. My point really is not about this case, I was going to the point that as a live Sound engineer (live shows) I have faced cases in which I don`t have a grounded system (I live in Venezuela) and if I have a ground Hum and I "ground" my system with an independent rod the hum will disappear so it looks like the Earth does absorb that noise

[@rutwiktechie]

Umm my tube amp has mild hum when nothing is connected to the amp just power , but when I connect my dac D50 to it through RCA and d50 to pc using usb b and optical ( spdif ) there's a lot of noise like interference noise , is it because of routers at the top of my cabinet or is the rca ?? This didn't happen with my SS A30 and dac d50

[@karstenkrause8737]

What about the old ‘ Dead man ‘ capacitor? Would that help

[@AudioScienceReview]

Help? No. It is a bad idea to begin with.

[@jaymz168]

We have 'Y' and 'X' caps for that purpose these days. Or you can just slap in a monolithic line filter module from Schurter, etc.

[@Leontheagent]

I’m so glad that all these stupid Audiophile beliefs are been debunked. Thanks Amir!

[@markphilpot8734]

Amir, I don’t know if you will have time to answer a question about this grounding subject or not. The twisting of signal wires has or has not any effect on noise pickup and does the routing of signal wires very close to the case matter in noise reduction. It seems to me that it should. I do know that transformer orientation can effect the noise level as I have seen this in real life from working on gear myself. The transformers were E core transformers which had no shields over them. Toroidal core transformers do not seem to have this issue, but they are laid flat and clamped down instead of standing vertically as E core types do. O Ring transformers are supposedly less noisy than even toroidal core transformers are. What do you say about this. Your comments are as an engineer so I expect your comments have more weight than someone who is not. I happen to respect Engineering comments. Too many know it alls around kicking those who don’t know but want to learn. Your words matter Amir! Stay safe my mates!😊👍🏻😷

[@Edwinvangent]

if a PC has SPdif and USB for a cable to your DAC, is USB still the better choice for quality or not?

[@AudioScienceReview]

See my response to your question in the other video.

[@Edwinvangent]

@@AudioScienceReview I did thanks for your golden insights... and measurements of course. there is another guy you should check him out, you will be friends I am sure. on youtube his channel is called " goldensound " or link kzbin.info/door/J0oW8D5z_IiFc7w46JJEuA

[@TechnicallyDude]

Amirm, i have isolation transformers feedind all my audio equipmente including pc, can i lift the ground from the mains feeding all my audio equipment since its all isolated ? thanks for this explanations.

[@cadetsparklez3300]

oh so the 2 ground pins connect to each other at some point? am I getting this right, because if they do that solves a lot of questions

[@cadetsparklez3300]

it also brings up a new question of why is there a 7 v dc difference from my safety ground to reference ground.. thats a bit concerning

[@reitencheng4878]

Why does an energized chassis shock you? How does it complete a circuit between you and the chassis.

[@philiptong4978]

because your natural electric potential is at ground level, unless you are charged up carefully kzbin.info/www/bejne/fHjSkouQrKufgJY

[@Mr_G]

What about connections with impedance matched balanced outputs, do they have 60 cycles noise like unbalanced connections?

[@AudioScienceReview]

They almost never do.

[@Mr_G]

Got it!

[@mbalunovic]

in EU, Neutal is not connected to the ground. if there is any voltage on the ground (leaking) circuit breakers turn off the electricity in whole house, not only one "lead". even shorting neutral to ground triggers the "leakage" breaker.

[@NikolaiBeier]

If a mains wire is not grounded somewhere, it is not really a "Neutral", meaning close to ground potential. (except for the rarely used "I-T" earthing system, which is is not meant to be used in residences and living spaces.) There exist 4 or 5 different systems of earthing in EU and Europe, depending on what you include in the count. Have a look at en.wikipedia.org/wiki/Earthing_system#TT_network The Terre-Terre (TT) system has a grounding electrode at the supply transformer (which can be far away from the residence) which is connected to the neutral. At the residence the protective earth is then taken for a local ground electrode (a rod, typically) which is not connected to any phase or neutral wires. This usually requires a' residual current device' to shut off power when a short to ground happens, as the current will be limited to much lower levels tan the ratings of fuses/'circuit breakers'. While neutral is not connected to the local grounding electrode, it is connected to ground at the remote end, by an other grounding electrode. Other systems are allowed and in use, like TN-C-S, TN-S and TN-C whre the neutral is grounded at the source and the protective wires at the consumers building are connected to that remote grounding electrode at the transformer.

[@EivindDahl]

I used a spectrum analyser on my phone, and a 50hz hum is the loudest ambient in my room. Does this indicate a ground loop? If so, can I fix it or do I need to get another room? 😅

[@gioponti6359]

Not 100hz? Transformers emit twice the net frequency i thought.

[@EivindDahl]

@@gioponti6359 Nope 50hz, don't ask me why.

[@riccitone]

Makes perfect sense...and I’m not an engineer. Very well diagramed and explained! PS Really wondering how far I would get trying to market “the dirt probe box” (jk) ; )

[@gherbent]

If the system is correctly designed we do not need grounding to the earth, grounding is eventually another antenna, but unfortunately, because of most of the PSU designs, we need to connect the components of the system to the earth (the third wire in our house outlets). Most of the switching PSUs have some condensers (usually >1.6nF) connected to the earth with high voltage noise which is better to cool down by connecting them to the earth. Some of the core transformers also have the inter-windings capacity (300pF and more) so they often do not solve the problem. I am focused preferably to use transformers with primary and secondary windings well separated (look for R core transformers) in this way obtaining a complete isolation.

[@cobelali]

Excellent video about grounding. Now I don't feel bad for not completely understanding this concept as taught in school. I just want to know who is giving thumbs down to this video 🤔