Thread: Measuring AC Power Line Noise

Any power line noise measurements need to be made with the circuit loaded. I use a 500 watt oil filled room heater near the meter test point.

But on the other hand, much of the power line noise will be generated by the hi-fi components themselves, so also test using the hi-fi system rather than the dummy load.

Just found an Entech Line Analyzer for a reasonable price but have not received. I thought about the Alpha Labs meter but I could not find any online manual and does not appear to be contact info readily available.

From online sources, cover of Entech unit says to adjust the noise meter to get 80-120 on display with Over-Range light OFF.

I assume this is done with unit unplugged?

Is Entech suggesting that 80-120 is an acceptable range? I am guessing less is more.

Originally Posted by joeinid

Welcome to the forum, thank you for joining.

Thanks, Joe.

Noticed that Jim Smith is a member...have read his "Get Better Sound" book and applied a portion of his guidance.

What are some suggestions on a real analizer that will test for high frequency noise, harmonics, DC etc. Anyone know a good all purpose tool?

Well designed hi-fi components should be able to deal with a goodly amount of power line junk. The real question is does any of this junk get to the audio line or speaker outputs. The easiest measurement is the output signal to noise ratio. With other equipment a FFT test and an O-scope looking for out of band problems.

a] I don't know anything about Ansuz.
b] Power issues are best dealt with by good hi-fi component design.
c] UPS and regen units often bring a new set of problems with them.
d] Power conditioner is an undefined label, each marketing department is free to set its own terms.
e] Most hi-fi systems don't need any power conditioning.

I know I am a little late to reply on anything, but recently I got myself a power conditioner, which was tested with the Entech Line Meter and the results were good. However, an audiophile friend of mine told me that all detecting devices are useless. So he took out his Alpha Lab Line EMI meter and showed me that my power conditioner doesn't do ANYTHING to minimise noise as the Alpha Lab shows almost no difference in reading.

Is he right? He then go ahead and told me that with his power conditioner, he tested with Alpha Lab and the drop is so significant ( to say that his power conditioner works and mine is just snake oil ).

Originally Posted by joeinid

Welcome to the forum, thank you for joining.

Thank you Joe!

Originally Posted by jadedavid

The Entech line tester is a very basic unit and fairly non specific.
It has both audible and visual references to allow you to both hear/see any changes.
As you have indicated, your power conditioner did reduce noise when tested by the Entech.
So, it is doing something. Just not sure what and to what degree. A lab quality meter or a scope can show some more detail on what is happening on your line.
You stated that your friends meter was for EMI. Anything else?
There are many variables that affect the quality of the AC produced.
Many manufacturers attack the problem in different ways and with varying degrees of success.
Did your power conditioner help the sound of your system? That's the bottom line.
There is always something better, but what do you really need?

Hi Jadedavid,

He was the Alpha Power Line Meter. I am sort of a newbie so not exactly great at the technical sector. He is proud of his meter and since his power conditioner pass the test with his meter, his conditioner according to him, is doing the job, whilst mine....is just a snake oil/fake/overpriced power extender.

Got a bit upset on this actually, knowing that I've wasted money and perhaps the Entech meter is just for fun and does not help.

Originally Posted by Jim Smith

I have the Alpha, but according to Carlin Gabriel, it is too restricted in bandwidth.

Restricted in bandwidth? I thought it has a broader range of bandwidth vs the Entech? Since the Entech covers 300 to 700khz whilst the Alpha covers like from 10khz to 10Mhz. Isn't that a way broader range than the Entech?

Originally Posted by Elberoth

None of them is a professional tool and a complete meter. They work in a different bandwitch (one may show more of the low freq noise and the other more of the ultrasonic noise) so their results may differ. It is best to use both to get the most complete reading.

Does it work in different bandwidth?

The Entech covers 300 to 700khz
The Alpha covers 10Khz to 10Mhz.

Fluke 199 scope meter and also a Power Logic Ion 7650. You need both. Find them used on ebay. The 7650 goes to 2,5 Ghz. That is well beyond and Mhz range.

As I said on other thread, what are you going to do with the info. The Ion will tell you just how much noise you have, but its not going to tell you how to fix it.

My friends at Schneider Electric use these 2 tools to diagnose noise from industrial Freq Drives and other noisy equipment. They then build filters to bock the noise from polluting the surrounding facility. They are very accurate tools.

Originally Posted by Willco

I recall Caelin Gabriel (Shunyata) said the narrower band the Entech measures is more appropriate to the noise which effects actual audio sound quality. It picks up AM radio loud and clear at our place.

Interestingly, we can sometimes hear radio broadcasts late at night without any receiving device other than our ears/brain. It sounds bizarre, but it's pretty common.

Is AM the only noise an audio system is concerned with? I am not an expert so I am not asking this sarcastically in case anyone wonders. I am asking it sincerely. In fact, noises and power conditioners are matter that I just heard about recently and got interested in because of my audiophile friend. So it suddenly got me into it.

Yes Carlin did mentioned something like that but I am getting a little confused of his position. Let me demonstrate. In page 1 of this forum he said :

"

The Enteq only detects and rectifies frequencies to around 700KHz which means is it completely insensitive to some of the most harmful noise frequencies - those in the 1MHz to 10MHz ranges. But hey it is inexpensive, easy to use and it is nice to be able to "hear" some of the stuff that is on your power line. Your dedicated power lines, rhodium plated outlets and large gauge wires in the wall in no way immunize you to power line noise "

What does he mean by some of the most harmful noise? Harmful to health? Harmful to an AV system output?

And then he quoted this as well then, on page 4 :

"

Some frequency bands are more important to the performance of audio equipment specifically our research indicates the the most harmful frequencies are in the 100 kHz to around 1 MHz bands and then secondarily from 1 MHz to 10 MHz. Interestingly, I believe that the Entech engineers knew this and designed their device to be sensitive in the frequencies from 300 kHz to 700 kHz range. "

Without a definition of what is " some of the most harmful " ( harmful to what ) in page 1 of his post and then following up with a second post which claims Entech can also help to detect " the most harmful … ( as for the performance of Audio equipment ). Without definition from himself about what he meant by each " harmful " word he mentioned, it would seemed like he contradicted himself.

Perhaps he's still around to enlighten me on this? Would appreciate it.

Originally Posted by Kingrex

Fluke 199 scope meter and also a Power Logic Ion 7650. You need both. Find them used on ebay. The 7650 goes to 2,5 Ghz. That is well beyond and Mhz range.

As I said on other thread, what are you going to do with the info. The Ion will tell you just how much noise you have, but its not going to tell you how to fix it.

My friends at Schneider Electric use these 2 tools to diagnose noise from industrial Freq Drives and other noisy equipment. They then build filters to bock the noise from polluting the surrounding facility. They are very accurate tools.

What I am aiming for is to be able to tweak and make my audio free of the noise that affects sound quality ( within the range of frequencies I am able to hear as a human ). I may not be able to do much, but with that info, it may tell me which power conditioner I should not waste money on. You see, without having this information, I will go ahead and buy every snake oil story from power conditioner manufacturers/sellers. They will test it with eg. the Entech meter and tell me see, how much it helps you to silence it out. And then you go, wow. Let's get this. Then someone ( like my friend for example that tells me, it's useless cause the Alpha MEASURES " 0 " difference in the noises filtered from that power conditioner and suddenly you felt conned.

Originally Posted by Jim Smith

I misspoke - the Alpha has a wider bandwidth but not the best frequency band.

But doesn't a " wider bandwidth " meant, it covers the bandwidth of the Entech as well? Meaning to say, what the Entech misses, the Alpha is capable of picking up?

Originally Posted by Elberoth

Harmful to sound quality.

In reference to?

Willy, your in for a long uncomfortable ride. In a general sense you can't hear the noise yourself. The problem is your equipment is affected by it and it responds by performing poorly. That is what people mean by harmful. Poorly may mean you hear buzzing from speakers or you hear buzzing mechanically emanating from transformers inside of your amplifiers or other associated equipment. It may also manifest itself as a hazy glaze over the overall presentation in your music. It may manifest itself as a reduction in the decay of notes causing a truncated or abrupt sound. It may manifest itself as etched fatiguing presentation.

Getting rid of noise is difficult. One of the biggest problems is many times you can hear the filtering device itself harming the music. The trade-off is, does that device do more good than harm making it a benefit in your system overall.

If you have radio interference good shielding may help. Good shielding could mean a run of MC cable from your panel to a metal box in the wall containing your receptacles. All of your cables from your receptacles would be shielded as well as all your interconnects. This in itself can cause some compression of the musical sound itself. And it may not get rid of your radio interference noise.

You can try a filter more specifically designed to clear noises in the radio frequency range at the distribution point where your cables distribute to your gear, then use shielded cables from there into your equipment. However a filter is just that, it is filtering frequencies and that may in itself distort the sound of the music more than the distortion the radio frequency is putting into your power lines or interconnect wires.

I have tried to resolve these type of issues myself. I have talked to many many people. I have never met or heard of a single person who knows how to put scopes on to a power line or into a audio system, hone down on specific frequencies of noise and distortion, then apply accurate filters to clean just those issues.

It's not only the noise on the power lines or what is received through your interconnects. It's the very specific amplifiers, preamps, servers etc in your particular system and how they are responding to that noise and or the filter put in front of them. Worded another way, a class D amplifier will react much differently to a filter than will a tube bass amplifier or a Class A / a b solid-state amp.

All dealers seem to have their favorite filter for whatever their reasons. Don't be too surprised if none of them work for you. Then again you may be incredibly pleased with the results from some of them. If there is any way you can try different filters in your system, that is probably the best way to know if they will actually benefit you in any way.

The only positive no harm done practice I have seen applied to the power in your system is better grounding of your panels, better wire from your panel to your receptacles, better receptacles, better power cords. All of that will help your overall stereo system to sing better. It however may do absolutely nothing to get rid of noise.

I have heard two stereos that are absolutely dead quiet. One has a very large equitech power conditioner feeding everything in the system. The house is in the mountains far away from any commercial facilities. The other system has absolutely no power conditioning and is located in a large residential community. Go figure?

If you have noise that is truly impacting your system and bothering you, I'm sorry to hear it. As I stated in my opening, you're in for a long uncomfortable ride.

[QUOTE=jadedavid;266523]

Originally Posted by willyg

Hi Jadedavid,
all are different

He was the Alpha Power Line Meter. I am sort of a newbie so not exactly great at the technical sector. He is proud of his meter and since his power conditioner pass the test with his meter, his conditioner according to him, is doing the job, whilst mine....is just a snake oil/fake/overpriced power extender.





Not sure if you are experiencing problems with the quality of your AC or if you are just trying to be pro-active.
Your friend suppossedly has a power conditioner that does the job. How about asking him to bring it over to your place for a trial on your system?
If it works to your satisfaction then you can get one like his and call it a done deal.

I am trying to satisfy the OCD in me to do the best within my capability to get the best I could from my AV. I am not even exactly sure unfiltered, if I could audibly hear them noises. However the OCD in me tells me, that his story makes system better. I couldn't exactly afford his power conditioner. But if his meter is the " one " to test if a conditioner can make any difference, I would get that meter and guide my future purchases.

He won't bring his conditioner as well, as for him, it's expensive to carry out and it's rather huge as well.

Originally Posted by Kingrex

Willy, your in for a long uncomfortable ride. In a general sense you can't hear the noise yourself. The problem is your equipment is affected by it and it responds by performing poorly. That is what people mean by harmful. Poorly may mean you hear buzzing from speakers or you hear buzzing mechanically emanating from transformers inside of your amplifiers or other associated equipment. It may also manifest itself as a hazy glaze over the overall presentation in your music. It may manifest itself as a reduction in the decay of notes causing a truncated or abrupt sound. It may manifest itself as etched fatiguing presentation.



Getting rid of noise is difficult. One of the biggest problems is many times you can hear the filtering device itself harming the music. The trade-off is, does that device do more good than harm making it a benefit in your system overall.

If you have radio interference good shielding may help. Good shielding could mean a run of MC cable from your panel to a metal box in the wall containing your receptacles. All of your cables from your receptacles would be shielded as well as all your interconnects. This in itself can cause some compression of the musical sound itself. And it may not get rid of your radio interference noise.

You can try a filter more specifically designed to clear noises in the radio frequency range at the distribution point where your cables distribute to your gear, then use shielded cables from there into your equipment. However a filter is just that, it is filtering frequencies and that may in itself distort the sound of the music more than the distortion the radio frequency is putting into your power lines or interconnect wires.

I have tried to resolve these type of issues myself. I have talked to many many people. I have never met or heard of a single person who knows how to put scopes on to a power line or into a audio system, hone down on specific frequencies of noise and distortion, then apply accurate filters to clean just those issues.

It's not only the noise on the power lines or what is received through your interconnects. It's the very specific amplifiers, preamps, servers etc in your particular system and how they are responding to that noise and or the filter put in front of them. Worded another way, a class D amplifier will react much differently to a filter than will a tube bass amplifier or a Class A / a b solid-state amp.

All dealers seem to have their favorite filter for whatever their reasons. Don't be too surprised if none of them work for you. Then again you may be incredibly pleased with the results from some of them. If there is any way you can try different filters in your system, that is probably the best way to know if they will actually benefit you in any way.

The only positive no harm done practice I have seen applied to the power in your system is better grounding of your panels, better wire from your panel to your receptacles, better receptacles, better power cords. All of that will help your overall stereo system to sing better. It however may do absolutely nothing to get rid of noise.

I have heard two stereos that are absolutely dead quiet. One has a very large equitech power conditioner feeding everything in the system. The house is in the mountains far away from any commercial facilities. The other system has absolutely no power conditioning and is located in a large residential community. Go figure?

If you have noise that is truly impacting your system and bothering you, I'm sorry to hear it. As I stated in my opening, you're in for a long uncomfortable ride.

Hi Kingrex,

Thanks for taking time to respond.

1. I am not hearing buzz from my system. Thankfully it isn't a severe problem.

It's basically my OCD. Its a case of, oh wow, somebody tells me only their system can give me a closer to perfect sound while mine, are way inferior. Brings up the OCD in me to find out,

1. If that statement is true
2. If that meter is really that reliable and accurate.
3. If that meter is really the benchmark into getting a dead quiet sound.
4. If I need to make my future purchases using that meter.

I am fine with my system right now, but always wondering, how could I make it any better, if there is anymore headroom for it.

The dinali is a well made for the purpose product
it filters and does not limit power although same say it does anyway.
It works on audio and video devices. I use a few methods to evailuate noise.
Hum is just bad and there really is no acceptable allowance but it's extremely hard to completely remove. Grounding of the equipment is needed but it does not remove line noise.
The type of psu used inside our products maybe effected or not depending on the design and care while being made.
Our front ends be it digital or Anolog is effected line noise and grounding
A bigger issue for amps or even transformer based power condtitioners is signwave distortion called dc on the mains. Transformers below 400 watts are much less effected by it due to the windings wire gauge. Now larger ones get hurt and anyone in the states of they can should wire there amps at 230 volt not 125 why is complex. Now any iso that is made to use 230 input and has a bal 125 output yields best results and this method lowers common mode noise. The dinali does this and more to a level we can hear. A combo is best for all front end where gain is high. But if one had to pic one to try try a dinali. Lastly we don't need a line mouse meter to know there is noise. All power has noise and our homes or even systems make it there.
An IEC socket has by code a part in it to lower noise being Pitney back onto the power lines.
Some feel it hurts there own setup.

Ps I don't sell any product but do know some really work.

Can this be done more accurately with a digital oscilloscope? Seems like plenty of options in the $200-$300 range on Amazon.

Yes it can but one must know what to look for
The Denali is a simple effective device.
Consider this. I don't make or sell products
And I make all of my own line noise filers.
Try one used it works
In fact since I'll bet they read this they or a dealer might consider a demo one that gets shared among the groups here.
I am willing to bet many would end up buying one.
Next level is Miguel tri point stuff he is the real deal too.
And a great guy too.

Originally Posted by Alrainbow

Yes it can but one must know what to look for
The Denali is a simple effective device.
Consider this. I don't make or sell products
And I make all of my own line noise filers.
Try one used it works
In fact since I'll bet they read this they or a dealer might consider a demo one that gets shared among the groups here.
I am willing to bet many would end up buying one.
Next level is Miguel tri point stuff he is the real deal too.
And a great guy too.

I'm just curious if a noise issue I have now is related to my power. I need 95VAC output for Japanese electronics.

If you live in the continental states it's too high at 115 to 130.
So I'm not sure what your question is

Originally Posted by Alrainbow

If you live in the continental states it's too high at 115 to 130.
So I'm not sure what your question is

Yes, I live in the USA but am using Japanese 95VAC electronics via a step down transformer. I seem to have a noise issue and I would like to see if that is on my AC main, is due to the transformer, or possibly something else?

Ok if ok let me ask you a question
What type of transformer is it ? A pic and make and model also what device are you using with it. More than one ?

Originally Posted by vortrex

Can this be done more accurately with a digital oscilloscope? Seems like plenty of options in the $200-$300 range on Amazon.

Yes it can, but only if you have the technical knowledge to use equipment like this on an AC power line. In the R&D lab we would hide the good O-scope probes from the techs. They often made hook-up mistakes and wasted the probe.

It's much better to measure the signal-to-noise ratio at the audio output of your hi-fi system. All this requires is a sensitive DMM.

Well designed hi-fi components can deal with a lot of AC power line noise (that's because they generate a lot of the line noise).

While measuring the output of devices can show noise it does not lend itself to why or where it starts
If we measure at the line or both line and psu dc output the given data is more conclusive reg power.
Lastly to Measure at the output is far more complex too.

Originally Posted by Alrainbow

While measuring the output of devices can show noise it does not lend itself to why or where it starts
If we measure at the line or both line and psu dc output the given data is more conclusive reg power.
Lastly to Measure at the output is far more complex too.

That's all completely backwards.

I recently purchased the Trifield EMI (Dirty Electricity) Line meter and its measurements say my expensive power conditioner doesn't filter any line noise. In fact, with some of my home's outlets the Trifield's readings say the conditioner actually increases noise. I've been told that this information is inaccurate because the Trifield measures the wrong frequencies for audio(phile) purposes. What's your opinion?

First, with well designed audio equipment power line noise is not a big problem despite the exaggerated claims of some.
But for the most part, the noise that audio equipment has to deal with is (lower frequency)noise and leakage currents flowing thru the wires.
the Trifield EMI meter measures (higher frequency) noise voltage fields in the air.

With regards to noise, the only meaningful measurement is the signal-to-noise ratio at the audio output of your component or system.

The more myself and some friends play with power, the more we are finding proper grounding, proper lacing in panels, proper distribution have a massive impact on noise. Even how many circuits you run has a significant impact. Your whole house was probably wired as a home, not as a performance audio/video playback location. Its NEC compliant, to a degree, but that is not always enough to make an environment optimized for noise reduction and audio playback.

In short, your power conditioner can not fix certain kinds of issues. I don't think there is near the noise in peoples houses as they think. Its mostly non optimum wiring. You may even have faulty audio gear. Who knows. It goes way deeper than "but I have 10 awg romex to my rack".