Audio hygiene 2 Power plug polarity

[@LandandLens]

Hans, The USA plugs you showed in the Video are polarized. Notice on the 2-pin plug that one spade is wider. This is the neutral. Also remember that in the in the US we mostly have 240v entrance panels that are split into two 120v phases and we have many problems with the neutral between the phases getting pulled to one side. For high quality stereo some of us like to run a dedicated circuit to the stereo using oversize wire, dedicated circuit breakers and high grade outlets. Checking the loads in a home to make sure the neutral "safe" is important. Note that we have found issues in homes where the terminals in the entrance panel have loosened slightly due to the 60hz vibrations that can happen. Having a qualified professional evaluate the panel is worth the cost. Finally reviewing the ground wiring on a three conductor power system to ensure that the ground and neutral are at the same potential. From my personal research and systems I have gotten great improvements in sound by managing the interconnecting COMPONENTS of my Stereo "SYSTEM".

[@TheHansBeekhuyzenChannel]

Thanks Bob for this info. I'll place it on top in the show notes.

[@brokenot]

60hz "causes vibrations"? By all means, have a qualified professional come to your home and when he or she arrives, tell them that the reason for their visit is because you read something on the internet and that you'd like your panel's screws checked for tightness due to "60hz vibrations and their tendency to loosen things up". Post their replies here.

[@chrisladouceur4093]

Many of the cable ends do not use the extra slot size though and are reversible in Canada and the USA. Does this mean it’s still worth checking?

[@anorris1212]

@@brokenot The only 60 hz vibration that I notice, is from a kick drum.

[@bradt.3555]

Was an electrician for 40+ yrs. Never seen connections loosen due to 60hz vibration but from heat. Heating then cooling over time can loosen a connection, really bad in houses back when they tried using aluminum branch wiring. Older 2 prongs were not polarized but all are now. every component that has a grounded 3 prong plug will have zero potential between them. I read zero even between my older stuff with non polarized 2 prongs as the primary side of the power supply is isolated and on the secondary side it's DC and allway's the negative is grounded. No matter which way the AC plug is in the rectified power is the same. Very old tube equip can be a problem, especially guitar amps as they grounded one side of the AC with a "death capacitor" with a switch to select which leg got grounded. Also tube amp's transform the voltage UP, like to around 500v or so.

[@rafaelpernil]

Few months ago I found out inverting polarity improved sound. Thanks for explaining how this works!

[@philiprastocny7236]

Excellent summary. Kudos for the explanation. I'm certain folks who try this will appreciate its sometimes highly-audible effects. The reason behind why reversing the polarity with the suggested reversing cord "works" is what is called transformer leakage. When flipping the phase of *any* transformer, the leakage current changes where in one polarity it produces less leakage current to the chassis than when wired in the other phase. Better transformers have essentially the same leakage current in both phased directions but there will still be a very small but measurable difference. This reversing-plug approach works great if there is only one transformer inside that piece of gear. Now consider the complication if your gear has more than one transformer inside. Flipping the polarity with the suggested cord flips the phase for all transformers. What if one is already phased properly and another is not? As you can see, this can be more difficult to do since the proper way to determine lowest leakage is to test one transformer at a time, something not possible with a simple reversing cord as mentioned in this video. Another way to test this leakage is to "float" the ground connection [deliberately isolate the grounding path between the chassis and the wall outlet] and measure the voltage/current with a DMM from the chassis ground to the ground pin of the wall outlet. This is far more complicated and again not recommended for the unskilled. When properly phasing multiple transformers, you must physically disconnect all but one transformer by unsoldering the wires to the PC board [not recommended for the unskilled], and assure the phase is at its lowest leakage with a similar test measured from chassis ground to the wall outlet ground [again, the ground of the power cord must be isolated to do this properly]. Proper polarity can be achieved by reversing the two wires on the transformer itself [or where those wires attach to the PC board]. Repeat for all transformers in that piece of gear one at a time and you are done. Do this for each piece of gear in your system and the noise floor should improve, sometimes dramatically depending upon how much the transformer leakage is reduced. This effect is commonly referred to the "blackness" in an audio/video system. And then there is assuring that all of your audio/video gear is on the same electrical phase from your circuit breaker box [problems with split-phase AC Mains systems like those in the USA]. Another topic on how to do this properly. Finally, there is the approach to physically isolating all transformers from the chassis. Here the only remaining leakage is then via capacitive/inductive coupling to the chassis again reducing the leakage. This leakage can still be improved with this proper polarity phasing approach. Unfortunately, if your transformer is heavy, physical isolation may not be possible.

[@TheHansBeekhuyzenChannel]

Thanks for sharing

[@kavelaarsJ]

" McGuyver a Cable" Brings back memories... :-D

[@johnbuford8715]

Excellent topic. Bob your information is extremly valuable. I just wanted to add how important the impedance between earth and ground. For delicate systems the impedance should be no more than 5 ohms. The liw impedance protects sensitive equipment from sperious voltages. Plus it tends to lower the noise floor in your system. It is recommended that the value of the impedance should be tested annually. Because it can change over time. Any increase over 20 percent should be addressed.

[@jamiermathlin]

UK plug are 13A as that is the maximum fuse size. the round pin unfused plugs are rated at 15amps

[@TheHansBeekhuyzenChannel]

Thanks

[@laurentzduba1298]

Since the 1990s, I've noticed that some CD players and DACs tend to perform better in the projecting a believable soundstage if you plug them to the mains in a particular polarity. BTW, since 1995, there are some pricey audiophile grade power strips that are equipped with a polarity switch that allow you to safely switch the polarity of your mains.

[@cekpi7]

Easy check to see if your phase/live and neutral wires have been wired correctly is to use voltmeter and check potential between wires, between live and ground you should have 120-240v, neutral and ground should have 0v or close to 0v.

[@ABWSKITCHEN]

Thank you for sharing this information!!!!!

[@TheHansBeekhuyzenChannel]

Any time!

[@carloslarard]

great article, you are brilliant. as contribution, for possible other video, it will be helpful to include a diagram how to test the ground with the chassis.

[@TheHansBeekhuyzenChannel]

Noted

[@nickwilliams1065]

Watched a demo in a Cheltenham HiFi shop back in the late 80's by Peter Belt. He reversed the polarity of quiet a few power cords and repeated the same track over and over whilst he altered them. I thought the poor shop manageress was going to go into orbit bless her. Did it make a difference to the sound we listened to that evening? Well i heard a subtle change when the amps power cord was changed same thing with a tape and cd and I wasn't alone in that view. There were also quiet a difference when when he turned the speaker cables the other way around, amp end into speaker, speaker end into amp, the guy over the years divided opinions of many so called hifi experts!!! I have a fairly expensive digital coaxial cable from cd to amp, its has an arrow indicating its direction for use, cd to amp, I have swapped it around and it sounds brighter, not good with an audiolab amp mission speaker set up. Works fine with the Arcam, Monitor audio set up though. Try it its free and you might be surprised by the change.

[@48snapper]

The two pin socket shown for the UK is only normally found in bathrooms. They have to be fitted with an isolating transformer. I don't think I've ever seen a two gang two pin socket on sale here in the UK. By the way, our rectangular pins type G system runs at up to 13 amps, not 15. Many thanks for all your excellent videos.

[@TheHansBeekhuyzenChannel]

Thanks for the info, Mains policies all over the world differ greatly, unfortunately.

[@marekwaczynski3894]

In my opinion L/N pins/cables should be connected that way to have L-cable ALWAYS connected to "on/off" switch of each unit. To keep transformer or whatever is down of on/off switch without power from back side when unit is OFF. Some switches are cutting both L/N but some only L. Just for safety. Rest is AC. In my opinion of course. Safety with 110/230 AC is number one.

[@TheHansBeekhuyzenChannel]

Grid architecture differs per country and even per region, I have learned.

[@marekwaczynski3894]

@@TheHansBeekhuyzenChannel No specific architecture in AC. One cable is L always under ACpower (coloured black/brown typically) (just use probe to find it) second is N - blue typically, third (if exist) is PE yellow green typically.

[@joaomantunes]

Interesting topic Hans. I would also suggest a video about mains conditioning filters. it has come to my attention that mains filter conditioners such as Dynavox X4000 an X6000 have an inverse polarity detection besides filtering mains noise. I would love to know if someone has any good experience with these products. What other mains filtering you would recommend?

[@glimmertwin86]

Thanks for the video. Is there more detailed information about how to do this? perhaps showing how to do this? Sorry if this sounds lazy, but I want to make sure I do it correctly without damaging anything.

[@dimitrispanayides6912]

I guess no extra video, but is easy. Take a polymeter.... that thing electricians hold, and place one end on the earth of wall socket and the other on the outer ring of any input or output on every device you have. One at a time. Inverse the plug and measure again, the lowest reading is the best position of the plug. You should disconnect everything except the power cables before doing this. I hope this helps.

[@dimitrispanayides6912]

And as Shrike9t1 said to me in another comment, devices must be plugged with no earth connection if it's a two conductor cable you don't do anything about it, if it's a three conductor you have to use an adaptor with earth lifted so you can check. Devices must be on. That's it

[@williamlau7179]

I am thinking, when reversing polarities can sound truly better, it could likely mean that the wiring connections of the components or at the walls (house elect system) are "wrongly" built. I always checked that the wall outlets + & - are rightly right. Then I opened the case of the components to check that the inlet +ve always has the fuse (if it should have a "first" fuse with right rating). Other than that, for safety reason, I never reversed the appropriate polarities. Components having double electrical insulation design is a different story that the 2-pin plug is independent of polarities.

[@TheHansBeekhuyzenChannel]

The problem is that worldwide there are all kinds of differences, even within one country. So what works for you might not work for others.

[@2adamast]

It's weird, of course if it works it's ok. I would expect that a good ground connection is number one (good hygiene). Where power phases are all rectified to DC, the interference of different rectifiers should be third order and unpredictable. Unless it's from a country (like the US) with an identified neutral phase wire *and* that is then also used as ground wire (but then it's an easy job for reviewers to catch that one)

[@alext2933]

Hi Hands. Great vlog. I am interested in your thought on balanced mains. I hope this is coming in part 3. 😊

[@TheHansBeekhuyzenChannel]

I am afraid that's too specific for this channel.

[@alext2933]

Thanks for the response Hans but am slightly surprised. I was thinking of the MVA Balanced Mains unit. £500 for 4 outputs seemed now financially viable as these used to be very expensive (and still are in some cases eg Russ Andrews). I would have loved your thoughts as studios have been using balanced mains to combat noise for years. I would value so much your input on this topic. Thanks. Alex

[@TheHansBeekhuyzenChannel]

I try to enthousiast people to switch from the lo-fi gear to decent audio equipment. There is no rational behind it but I feel yet another box will scare people of. Imagine you are going to buy a car and you consider it a lot of money since up till now you drove a moped. What if you then were told to spend an extra 30 to 50% on something you don't understand for otherwise the car will not drive well enough. IT is fine to be told to rotate your tires after x-thousant miles, fill up the windscreen wiper fluid, check oil and tire pressure. But spending a significant amount on money to have an already expensive purchase work fine....

[@alext2933]

I understand your point. I just thought it was another well regarded mains tweak you could run through. Sorry of I have wasted your time.....

[@TheHansBeekhuyzenChannel]

No, thank you for the suggestion and thinking of new topics. This one didn't fit, but the next one might. You didn't waste my time at all (and I am a fast typer anyway;-)

[@ericjensen9091]

I think I can live with the occasional yet rare hum. Therefore, I can live. When the day comes for me to finally go beyond Cds and vinyl I'll look to your video instructions Hans. Thanks.

[@TheHansBeekhuyzenChannel]

This isn't about hum but about resolution in audio. But it all depends on the local grid topology if it is possible, allowed and useful.

[@ericjensen9091]

The Hans Beekhuyzen Channel Yes sir. I didn't mean to be critical. I accept your correction and appreciate your straight forward style and honesty.

[@TheHansBeekhuyzenChannel]

I didn't feel offended, I just thought I needed to clarify a bit more (my family says I enjoy teaching.....)

[@ericjensen9091]

The Hans Beekhuyzen Channel Teaching is a noble endeavor.

[@emmettsullivan690]

What if I provided my system with a 230 volt (USA) 20A double pole split branch circuit with two outlets, one on each phase? One or the other would give the quieter result for each device. Then I could assign each one to the L1 or L2 side accordingly. I wouldn't need a reversing cord and, no neutrals would be switched or fused avoiding a safety problem.

[@TheHansBeekhuyzenChannel]

I have never tried so I can't say.

[@laszlobarchet2646]

I am an electro-technical officer on an ocean-going cargo ship. According to my education, it is really unprofessional to talk about polarity in AC power. From other hand I am using stereo equipments on board of my vessel. And check this out: on ship there is NO neutral (or return) line! We have only phases (3 of them) and all the sockets are connected to 2 phases and a PE. So I have no idea for what the God sake should I reverse the poles of my cable (or socket). And guess what? All my equipments are working well. So far I did not check the voltage between ground and the chassis, but I will do that. If I can find some significant voltage, then must be something abnormal with the certain equipment's power supply. Please correct me if I am wrong.

[@TheHansBeekhuyzenChannel]

You're wrong. But I didn't say the equipment won't function if it's the wrong way around. I said it will sound better.

[@damnzzz8]

Hello Hans, I've seen this video and after that I saw your video about voltage supply's. As you are advertising to change the polarity of the plug of the mains, I would love to see some additional substantiation regarding this matter. For now, the part of the voltage supply's fully contradict this video. Thank you in advance Rob

[@TheHansBeekhuyzenChannel]

It’s an old video. In the mean time I learned that there are clear differences in grid systems world wide. The same goes for legislations. The differences in sound quality are due to leakage current that differ depending on the polarity. In Europe it is easy just to reverse the plug and thus test for the lowest leakage. Be careful in other situations.

[@damnzzz8]

Thank you for your reaction. I'm aware that this an old video, but not less actual. As were using AC as mains and rectify this to DC, what does it matter to change te polarity? The polarity of DC will stay the same. As you just mentioned the leakage of several components generates some potential on chassis. This is DC, so measurements to the wall-outlet does not give you any useable information. Futhermore the transformer gives a galvanic separated circuit, what can give very dangerous situations when measuring.

[@kirlu50]

Since I saw this video the first time, I bought an ifi power conditioner. And I am absolutely screwed, because no matter which outlet in my house I plug it in to the polarity led is red. 🤔 And no, the power conditioner is not defectous.

[@TheHansBeekhuyzenChannel]

Power lines differ greatly from place to place. That’s why I don’t review them.

[@kirlu50]

@@TheHansBeekhuyzenChannel Thank you for the unexpected response. You are above and beyond. I live in Copenhagen, and I believe the power supply should be good. So now I have this obsession that something is wired wrong. I may have to move. 😊

[@wimoorthuizen5011]

Hi Hans, In the context of audio hygiene and the source, I would like to know whether it is desirable from the point of view of better sound, to connect my hi-fi system to an earthed socket. I don't have that now and I'm curious if I can make an improvement with it. Kind regards Wim Leiden

[@TheHansBeekhuyzenChannel]

It usually is better to have your stereo connected to an earthed socket. It will never have a negative effect on the sound quality and in most cases the sound quality improves, especially if you check what polarity of the mains plugs gives the lowest leak current.

[@johanpetter3455]

Hello Hans, I have a question about checking the polarity of the Hifi components. In your video you don't mention about the components switched on or of while measuring the AC voltage. It makes in my case a big difference, especially with my REL T7X subwoofer. On some websites I see that the component should be switched on, but on some I don't see that at all. Can you clear up this issue for me/ us ? B.R. Johan

[@TheHansBeekhuyzenChannel]

Have it switched on.

[@thomasstedtenfeldt5051]

Do different HIFI component have different phase depending on how they where produced? I.e, are we not only trying to follow the standard of the electric company, but rather try to help issues introduced by the stereo component manufacturers?

[@TheHansBeekhuyzenChannel]

It's more about leakage of the transformer that is stronger one way than the other.

[@thomasstedtenfeldt5051]

@@TheHansBeekhuyzenChannel I see, so regardless of "phase" on the power grid it is a device by device problem. Basically all power cables from a same brand are not going to be setup in the power conditioner the same way?

[@TheHansBeekhuyzenChannel]

correct

[@thomasstedtenfeldt5051]

@@TheHansBeekhuyzenChannel Thank you very much for your time. I have now decided to take up woodworking as my hobby instead ;) //Thomas

[@TheHansBeekhuyzenChannel]

Please do keep track of the wood grain, keep it length wise😁

[@giot1302]

The device measured should be switched on or off?when switched on i have the opposite results when measuring ac. The value measured is greater when iec plug is wired correctly!

[@TheHansBeekhuyzenChannel]

It should be on

[@giot1302]

@@TheHansBeekhuyzenChannel Firstly i would like to thank you for your response.But the fact is that despite the fact that the 'hot' is at the correct pin of the iec plug,when the amp is switched on the multimeter gives higher ac measured value between chassis and ground!

[@franciscoortiz6980]

Now days ALL electronics in USA has Asymmetrical (not reversible) plugs. By the way I use affordable hospital grade ac power cords.

[@TheHansBeekhuyzenChannel]

Thanks for sharing

[@Mr02stu]

Affordable? I paid $55 for an isolated ground, hospital grade, 20 amp duplex receptacle. Ran 3 insulated 12ga conductors, one for the plug ground, and used our (Canada) uninsulated ground along with the armoured cable to be a entrance bonded shielding. Used a stand alone 20 amp breaker, and soldered this to be the first load on the buss bars.

[@dimitrispanayides6912]

Hans, thank your for your video. I made measurements on my system and finally reversed the polarity of the tuner, it had different readings. Have some questions though. Amplifier show same reading both ways, reading is absolute zero. Is this OK? CDblueray player shows same both ways but reading is 38, isn't that too much? Should I worry? Shouldn't be around zero?

[@harpalchauhan428]

5 days long for a answer i would try find out on google

[@dimitrispanayides6912]

@@harpalchauhan428 yes, he must be busy doing all these videos. But anw, shrike9t1 answered me on another post, I was doing it wrong anw...

[@INCC74656I]

question, if one were going hdmi from computers to a receiver to a tv there is great potential to have a difference in the ground plane. would using a UPS with AVR tech be sufficient to eliminate or at least reduce grounding loops? that is to say rather than using the wave forum from the mains you generate your own synthetic AC current from a power supply system to fully isolate you from the mains?

[@TheHansBeekhuyzenChannel]

No, in most cases it won't.

[@INCC74656I]

ok, to find the difference one could meter from grounding shield of a speaker port on one device to another while under normal operating load to see the potential, right?

[@dirknorris6639]

Hello Hans, thanks for your very informative video series. I am wondering about one thing about a while and I think I just ask. You are saying in this video to set the voltage meter to DC. I have always done the polarity check with the ground of the power cord detached and AC voltage meter settings. The polarity with the lower value I use for connection. Do I have to do my measurements again in DC or can the AC value also be used? Best regards Dirk

[@56ctconger]

AC is correct

[@richardobannon6301]

Hans, I have a seperate power coming from my meter box outside and a custom outlet box which all of my audio is plugged into. Can I just reverse the connection at my meter box to achieve this?

[@TheHansBeekhuyzenChannel]

I am not sure what is allowed in your country but in The Netherlands that would be forbidden. And unnecessary. If reversed polarity is sounding better, simply construct a power cable with live and neutral crossed using separate connectors. But if you are not sure, please get an expert. The high voltage of the grit is not to be fooled with.

[@soundfx2222]

Hello Hans, Thank you for the series on Audio hygiene. I have seen your videos on DC power supplies and would like to request a series on the AC side as well regarding AC Power conditioners, UPS's, surge protectors, and so on to increase good audio sound and protect our audio investments. Would you please consider such a series . Thank you .

[@TheHansBeekhuyzenChannel]

My videos ware watched in 160 countries and the differences between the grids differ not only per country but even per state or province. It would be very difficult to evaluate all those grids technically an legally.

[@craigseverin668]

Flipping the figure-8 connector on my modem/router used for streaming, etc. worked wonders. The modem/router has a switching internal power supply. Since I could switch the supply, I have it and all the other switching power supplies for cooling fans, lighting etc. plugged into a distribution component that plugs into its own wall outlet to keep them separate from the distribution component I use for the components having linear power supplies. The power cable itself used here is one I made using Neotech cable and Furutech connectors, so other's mileage may vary.

[@babeksaber2702]

Thanks for the video Hans. I do enjoy watching them, I did buy SOtm Ultra on the back of your recommendations. Great device. However I do have great reservations on your suggestions here. Two issues do bother me. Firstly, the circuitry inside audio devices are designed to take the phase/neutral through specific entries/pins. Many problems can be caused by changing this assumption, e.g. a potential fuse can be used on a neutral line!!! etc etc Secondly, we are assuming Amp/DAC etc designers are not so smart, which begs the question, why aren't we building and spending years designing and getting master/PhDs in electronics/electrical/audio sciences? :) Apologies for not conforming to the usual appraisal type comments. But I do have a lot of respect for your work to just simply clap!!

[@TheHansBeekhuyzenChannel]

I am afraid designers are limited by budgets rather than being ‘not so smart ‘. Changing plug polarity does improve (or degrade) the sound on a well tuned system.

[@berrycitroen2541]

There's a pole checker available from van den Hul costs €28,50 and thanks for the vid.

[@MegaF1guy]

Wouldn't just making sure all your power plugs relate to the same outlet reduce most of the chance of hum? is it not true that this would make sure all your components were at the same ground potential and thus reducing the chance of hum? Great videos! Cheers

[@TheHansBeekhuyzenChannel]

That is important too.

[@shrike9t1]

You have to put the Meter to ac, Not dc

[@No_Limits_411]

Any response there, Hans?

[@dimitrispanayides6912]

But when checking devices the voltage is already transformed to DC by the device transformer right?

[@shrike9t1]

@@dimitrispanayides6912 Not the Potential to ground or other devices, That is a induced voltage to the Housing/whole Unit.. To do That measurment it has to be Done without Connection to ground of the Unit itself, then set the voltage Meter to ac and Connect from the housing / rca ground to the ground of the Power Outlet. And there is usually a difference in the measurment when turning the connector 180 degree. But if the Unit has a switching power supply, there is almost no difference , Maybe 1V Or less , let the Voltmeter sit for 1 Minute, then Turn the Power plug and Again wait Some time...

[@dimitrispanayides6912]

@@shrike9t1 OK. So I guess Hans forgot to mention that earth must be disconnected right? I was wondering... this test is not for three pin plug devices but just for the ones with two pins? Also, do devices have to be switched on before measuring? Thank you shrike9t1

[@shrike9t1]

@@dimitrispanayides6912 yes, it has to be switched on and no Connection of any Cables at all and no contact to other Units with the housing etc. If the Unit has a two Pin connector then you have no connection to ground and the measurment is easy. If you have a 3 Pin connector then you have to make an Adapter with no Connection to ground ( and only use it for measurment , But that is obvious i think :-)

[@genez429]

did you said to measure for DC? Not, AC? I am in the USA.... I never measured for DC and always find one orientation of the AC to give a lower reading off the chassis...

[@chrisladouceur4093]

Does using “power bars” create any problems? How can I evaluate it?

[@TheHansBeekhuyzenChannel]

what are power bars?

[@chrisladouceur4093]

Maybe they have a different name there? I’m referring to a surge protector that has multiple outlets and typically is extended out from the wall

[@josvanzetten]

Sorry other readers, my comment is in Dutch. Beste Hans, Heel leerzaam en nuttig, ik ben inmiddels druk bezig de hygiëne op orde te brengen. En boek duidelijk positieve resultaten. Graag zou ik meer willen weten over wel of geen randaarde. Komt dit nog aan bod in een vervolg?