PS Audio Noise Harvester Review (AC Filter)

[@ggroch]

I actually like the Noise Harvester. For only $99 you get a genuine PSAudio accessory that does nothing audible, but it blinks and makes you feel better about your system. Most PSAudio accessories like power cords do nothing, cost many times more, and do not blink. Its a bargain!

[@MrMftech]

Blink is Bliss !

[@ChristianGoergen]

Over there in Boulder they appreciate such approach.

[@Antoon55]

I must admit I have 2 of their power cords and I have the courage to admit I hear a difference. I don't believe in Magical Voodoo gadgets but sometimes something works and in my case that's those cables :)

[@PapaWheelie1]

@@Antoon55 how tiny were the wire in the cable you swapped them out for? I can’t imagine there are mains cables that are so thin they would starve a home stereo amp.

[@-dubu]

@@Antoon55 I believe you that you hear a difference :) That does not mean there is a difference, though

[@Audioholics]

Amir dropping the Hammer on the Snake Oil. Time for a tag team my friend ;)

[@ggroch]

Great idea. I'd like to see you guys discuss in clear terms how cognitive biases work, and how they impact what we hear, the audio industry, and audio reviews.

[@vintageflanker7096]

Hi Gene, He already responded there: www.audiosciencereview.com/forum/index.php?threads/rf-interference-in-speaker-cables-video.20520/page-6#post-679038 😉

[@JesusMartinez-mk6fc]

You drop plenty of Hammers on Snake Oil yourself my friend. Yes a video collaboration between you and Amir will be great and a highly anticipated event by audio enthusiasts that seek scientific and empiric based reviews.

[@ericharrelson2045]

You two together would be quite the spectacle.

[@iowaudioreviews]

Please do. YOU HAVE THE POWER Gene-Man....LOL.

[@59seank]

Thanks, Amir. I like how you explain things.

[@AudioScienceReview]

Appreciate the feedback. The video format allows me to expand a lot on what I do in written reviews.

[@MassimoFantinato]

@@AudioScienceReview Another plus compared to the written reviews is the "emotion" or "human" factor that effect especially those who trip on snake oil stuff. A face and a warm calm voice does more for those people than 100000+ graphs. That's also why Paul from PS audio has a lot of followers even if he tell a lot of salesmen bullshit.

[@cau8365]

@@AudioScienceReview Thank you, your channel is making waves...keep'em coming.

[@jf542]

this channel is such a breath of fresh air!

[@AudioScienceReview]

:)

[@danielgeiger7739]

Wonderful! recently watched Paul discuss this item. I should have picked up on the LED's energy capacity (next to nil) as opposed to some major disco flashgun. Thanks also for the explanation re filtering in HV AC vs LV DC. Make a lot of sense.

[@cryptout]

Wow Amir, you really sunk you teeth in producing videos! I’m loving it, keep it up!

[@BuzzardSalve]

One of Amir's videos is more enlightening than one hundred of Mcgowans videos which are all about drumming up business for himself !

[@-aexc-]

i thought these products were jokes that no one believed until i found your channel

[@aerofart]

While everyone who knows Amir and the work he does appreciates his contribution to sanity and our pocketbooks, it really makes me sad to think that he is only one of maybe a handful of heroes out there. Maybe the only one. We are very fortunate to have you on our side, Amir. Thank you.

[@alainsanmiguel6827]

You Sir is the Man, The Legend. No Bullshit review just science and facts.

[@danryan4272]

Technically this is a BS review... BS Audio that is.

[@mysock351C]

And to think that people spend thousands of dollars to buy a PS Audio power plants to make pure, harmonic free AC. The pure AC is then put through a bridge rectifier and turned into noisy pulsed DC only to be filtered again inside the amplifier. Or even worse, charge up some capacitors in a switch mode power supply, which itself is probably one of the largest sources of noise in the audiophiles listening room.

[@AudioScienceReview]

Very good point. I actually have one of their older AC generators. Will do a test and review of it in the future.

[@mysock351C]

@@AudioScienceReview That would be cool! Any chance to get a peek inside during the vid? Curious to see how they work.

[@H-77]

Assuming it does what they say it does (and I have no reason to believe it doesn't), those Power Plants could be fairly useful where line noise and distortion does cause an issue. If they made a 2u or 3u rackmount version (even with cooling fans) for a less insane price I'd probably buy one for my lab. That idea isn't completely moronic, but most amplifiers these days shouldn't really care too much about the AC line that's coming in.

[@mysock351C]

@@H-77 It would be quite handy for use with something like single-ended triode amps (if your into that sort of thing) or other equipment that does not reject line noise/variations very well. Most commercial solid state amplifiers will have little issue handling variations, though. I've had some linears that will happily play through brown-outs that even take out the lights. The immense loop feedback just compensates for the loss of line voltage. On top of this, most linear class-B amplifiers have unregulated linear supplies, so they don't really care to begin with. I agree it can have its uses, but its massively oversold by Paul and PS Audio for what it can do.

[@H-77]

@@mysock351C True, but some solid-state amps are actually quite sensitive to the incoming AC line. During the early 1990s, Quested used amplifiers from a company called Omniphonics, and these were really bad in this regard. They didn't have enough input filtering and they use a toroidal power transformer that has a fairly high bandwidth. They're also really sensitive to grounding issues. They are a good example of an amplifier that would probably benefit from something like the PS Audio power plant. It's all well and good to say that an amplifier shouldn't have those issues, but the fact is that there are plenty of very good amplifiers from an era when line noise wasn't the issue it is today. Of all the audiphile products to market, power regenerators aren't completely stupid (assuming they do what they claim they do). They're not for everyone- it depends on how nasty the line noise is in your area and what equipment you're using. They aren't going to make things sound "more musical" or anything like that, rather, I see them as more of a way to fix problems. Some vintage outboard gear can be sensitive to this as well. It already sounds very "musical" (because it adds so much distortion), but noise can be a real pain to get rid of. If I were PS audio, I'd market them to the recording studio crowd.

[@young_padawan]

The first time I came across ASR was after googling a review for an amplifier. Before that day, I'd always get swayed by the latest hi-fi review with words like tight bass, airy treble, bright, forward midrange, honey-like, etc. Most audiophiles fantasize about an end game system - as would I. But I'd always be confused, should it be a Yamaha amplifier? Or a primaluna? Or maybe Cary audio?... Tubes? MOSFETs? And what about the speaker? Klipsch? Focal? And dac? Oh my the DAC! R2R? Delta-sigma? Not to mention the power conditioner, the hi-fi stand (to avoid microphonics). And oh oh! Would I also need an upsampler? A reclocker perhaps? Let's not even going to vinyl vs digital... I still remember when I first visited ASR to read a review on the schiit aegir, and saw the amplifier ranking graph. Now, my dream system is - benchmark pre and power amp, some neutral speaker, and perhaps a decent dac from the likes of matrix audio. I'm no longer swayed by the audiophile reviews on KZbin - though I still do watch them for laughs or entertainment. This was a long comment but you ought to know the significant impact ASR brings to budding audiophiles! Much love!

[@young_padawan]

PS - I fell out of love with traditional hi-fi reviewers the day I auditioned the Klipsch RP 600M back in 2019. To think I was almost about to buy it blind based on the unanimous praise everyone showered on it! And then I auditioned it at the dealer and it was 🤮🤢!! It just didn't sound right! Later I read the review of the same on ASR and could completely relate to your conclusions - the speaker design is broken! That's the day I decided to trust numbers over opinions. ❤️

[@jusjash]

Young padwan you have outlined what I have concluded from my vantage point. Your comment should be posted on ALL audio site.

[@young_padawan]

@@pkdude5334 completely agree! The cabinet resonance was also a big no for me.

[@curtgozaydin922]

Amir, your engineering talent and explanations are much appreciated. I hate the “snake oil” and over-bearing mystical gizmo/sounds better/audio has more shine/has more width and “air” type non-measurable stupid crap being touted by the “high-end” purveyors in the audio industry these days. You are shining a light on this nonsense! 👏🏻

[@jblesser]

Once again, thank you for your extremely knowledgeable, low key approach to investigating these devices

[@Leeloo102007]

Thank you Amir for enlightening us all with your wisdom! I’ve spent so much money and time with tweaks in the past... Most won’t work, especially when dealing with solid state gear. It’s easy to be seduced by an idea and insist on believing in it...

[@avgeek8810]

I’ve been waiting for you to do KZbin videos. Thank your and regards from Sweden. Also if possible a review on the Furman 210 “power conditioner” would be interesting to see a review on.

[@scottm1953]

Thank you for making these videos Amir. Love this channel. Clear explanations with no nonsense. I head over to the Hans Beekhuyzen Channel when I want to laugh at some audio voodoo.

[@AudioScienceReview]

:) Thanks for watching Scott and commenting.

[@philbarone4603]

I’ve been involved with audio stuff for about three years now so that’s not very long but I’ve been making instruments for over forty years and let me tell you, SO much of this stuff that we talk about is psychological which is why I like Amir. He has no problem tearing down a product because he’s not profiting from it. In my opinion, there is absolutely no reason why we should trust people doing reviews when there’s something to gain from it like Steve Guttenburg, or Andrew Robinson or a few other guys. Just the fact that they’re getting gear to review without any outlay and nothing to lose taints the review and favors it. I’d like to see Amir make some of his own products because I’d feel safe buying them and I’ve bought a few things based on some chucklehead telling me to buy it. Just bought a power cord and I probably don’t need to tell you my results and I’ll just add that my wife has a Masters in technology and she studied how cables and wires work and she says that you’ll only get a positive result up to a certain level provided that the cable, wire or whatever is of reasonable build quality.

[@noliyoshida7486]

So awesome having Amir on KZbin! I'm a long time lurker on ASR

[@JesusMartinez-mk6fc]

Brilliant Amir, a great choice to present on YT from your ASR archives. This reminds me that some years ago, I had purchased a Nordost QRT Qv2 AC Line Harmonizer in the Nordost room at the Montreal audio expo. After listening at the demo of the device by Nordost and been persuated that I could hear a notable improvement in SQ, like most other folks at the demo, and with a 30-day money back risk-free guarantee if you didn't like it in your home setup, I figured what the heck. These Nordost cable demos are so dubious, specially with that German sounding guy performing the demo and telling you that what you need to improve the sound in your audio setup is not a better amplifier or preamp but better cables, Nordost cables of course. You always seem to hear an improvement at those demos and in retrospect, one wonders if there's any monkey business going on behind the scenes. Anyways, I connected the gizmo into my AC audio distribution bar as directed and after repeated and thorough testing, I couldn't hear any improvement whatsoever. So back it went for a full refund, thank you.

[@AudioScienceReview]

Thanks Jesus. As you, I too can "hear the improvement" in those demos. I find that if I don't listen to their pitch however, I no longer do!

[@stopthefomo]

You clearly have very clean power - maybe you need to live in the Bronx? Another great review my friend!

[@nostro1001]

I love that..."just because it filters some things...", that was gold. Excellent review of a pile of junk. "Harvester."..somebody has a clever mind for marketing to the misinformed. Thanks!

[@danryan4272]

they're harvesting something... but its green and it doesn't make noise.

[@idray986]

Like and subscribe fellow audiophiles, we need Amir to rid the Audio world of snakes!

[@bobe2933]

I love this channel. I bet money that some of these manufacturers don't like you now :D Thanks for saving me money! :D

[@AudioScienceReview]

Yeh, it is not a good way to make friends in some parts of the industry. At least before I did videos, they didn't know what I looked like! I am not sure how I can go to any audio show anymore....

[@vitalii1372]

@@AudioScienceReview That was a brave coming out. I’m pretty sure you will also meet many fans on audio shows. Prepare to be famous!

[@danryan4272]

@Douglas Blake The best video ever would be Amir walking around to all these vendors at a big show. LOL. 'Here is the Audioquest booth... I reviewed one of their RCA cables..."

[@drdelewded]

@@AudioScienceReview If they are in Toronto, Ill have your back.. Non of these old coots would step to you with my 350 lb biker looking 6 foot 1 mass next to you haha.

[@chriswithall2518]

Another GREAT bit of engineers analysis Thanks Amir.

[@thenetpagan]

Amir, I'm so thankful to have you in this platform producing content, very valuable and needed for our hobby.

[@squidcaps4308]

I have talked with MacGurkin, i mean MacGowan. The man is a charlatan and he knows it. He is a competent engineer, which in this case means he has designed the filter to be high enough so it doesn't actually do anything to filter to 50/60Hz.. as that would mean it has to actually do something. But, as it is only affecting >500Hz... it isn't really doing anything to mains noise, it is those first harmonic spikes that are the worst problems. But those are expensive to fix. edit: heh, of course it is said at the end of the video.. The moment i saw that it affects >500Hz i knew why: because it doesn't do anything, no good but also, no harm and will be safer.. and cheaper to make. That is exactly how i would do it. Paul MacGowan is a charlatan and a scammer and HE KNOWS IT.

[@BogdanWeiss]

@SquidCaps I have to call you out on calling MacGurkin a “competent engineer” the guy can not draw an elementary circuit diagram !!! Lookup the Poo S Audio video on “biwiring” - it’s a parody of blatant incompetence & Paul Poo S Audio completely misses the point of “biwiring” in an “explainer” video on the very topic - it’s hilarious BUT also tragic that people can’t see the obvious BS

[@herrtrigger7220]

@@BogdanWeiss Paul is a classic case of the emperor's new clothes. Who is going to challenge him at his own company?

[@BogdanWeiss]

@@herrtrigger7220 They also delete comments pointing out obvious nonsense - they can't take constructive criticism & Paul can't draw an elementary circuit diagram....pathetic...

[@geoff37s38]

@@BogdanWeiss also look up videos on audio fuses, elevated speaker cables,phase distortion etc. etc. he is a dishonest smooth talking salesman with superficial engineering knowledge.

[@chrisulmer3925]

Damn glad you're producing these videos.

[@peterlundskow4061]

Thank you so much I was about to go down this rabbit hole & appreciated the section where you discuss difference between AC filtering & DC filtering, etc.. Saved me both time & likely money. I had been considering this as well of other products from this company but will now look elsewhere. Their audio equipment may be fine but I am not interested in a company that is not completely ethical about everything it makes & sells.

[@StewartMarkley]

Great job on this Amir. I'm looking forward to your reviews on power line EMI filters, both when filtering the AC main and when placed at the output of several power amplifiers, ideally class AB and D. I want to see if you can measure any difference on the speaker end of a speaker cable with and without the filter. Also in addition to your usual FFT analysis, can you show us a scope display of a 1kHz square wave with and without the filter? I am interested in if EMI noise can somehow change the waveform, and thus potentially the sound of a signal. And please use various common sources of EMI such as a SMPS, a computer, a monitor, an in use cellphone, a fluorescent light, etc. to see if you can induce any measurable differences and especially the sound and if EMI filters will help. Danny from GR Research claims that EMI somehow affects the soundstage and detail of music. As these qualities are associated with phase and group delay, if EMI can measurably affect the waveform of a square wave at a speaker's terminals, I want to see that. Thanks for the great work.

[@Nonamehere1]

Excelent ideia!

[@TonicofSonic]

I hope everyone understands the significance of this video. This marks the golden age of Hi Fi, as snake oil has never been harder to pass off onto consumers and technology has brought us some truely amazing speakers, so long as you take inflation into account and spend more than a night out on the town on your speakers.

[@carlosoliveira-rc2xt]

Why don't you get him to prove quantum effects?

[@johnolson4977]

I have ears ,what a great line .....another great example.

[@shean-koklim4197]

Thanks for the insight Amir, appreciated.

[@AudioScienceReview]

My pleasure. Thanks for watching.

[@andysummersthxcinemaandmyc7748]

So it's a PS audio Snake harvester Oil and it's not even 1st April yet. 17:08 There is a place here in UK called Harvester where you go and eat. So what is inside the PSnake audiOil harvester? A few resistors and a capacitor that charges up with a blinking LED.

[@robertkjeldsen1611]

Amir. Really enjoying your videos! Keep up the very important work! Our community of music and gearlovers are all better for it! Thanks!

[@williammay8413]

Glad someone can say it cuz I have been on my own about cords and power conditions and spending lots of things that don’t make any improvement

[@Mrch33ky]

I think you hit the nail on the head right at the end - the dopamine high - that people get when they believe its doing something. Similar to the way F4ce book was designed to constantly hit the pleasure centers of the brain to keep you coming back for more screen time.

[@jungtarcph]

Love to see Paul respond.

[@axbarker]

Amir, I think your videos are fantastic. I am an audiophile, an enthusiast, but I also have a PhD in Power Engineering and have always worried about "quality connectors" and the like. I would be very interested if you you have looked at the impact of power conditioners and regenerators on the quality of DAC analogue output? Do they actually make a measurable difference? On your testing process - it seems to be essentially "steady state" ie measuring total distortion and jitter improvement or the lack there of for a constant steady single frequency input. Question, the likes of Chord focus a lot on dynamic and transient response to enhance listening quality. Could your test process be extended to see if any of these devices change (good or bad) the impulse or step response of DAC outputs? I appreciate you utilise AB blind listening tests as the ultimate comparison, but in terms of measuring is a dynamic test worth demonstrating that these various devices add nothing in steady state or dynamically. Great stuff keep up the good work - looking forward to a review where something actually does what it says on the tin

[@RillenReiner]

Thank you for your review! Very helpfull. I own several of the PS Audio Noise Harvester and I have to admit that I thought when I had put them in all in at the same time, that their was a more black background (listening to music with my headphones via a Meier Audio Daccord and Classic and Sennheiser HD800). But I agree with you that when doing A/B blind, there would be no way that I could tell if they are running or not. Would lover to see your measurements of the iFi AC Purifier who claim to be active noise canceling.

[@njm1971nyc]

Oh man, with those several hundred dollars you could have bought something useful 😕 Instead, Paul McGowan is spending YOUR money on a filet mignon & a nice vintage Bordeaux. I'd sue him!!

[@CyberBeep_kenshi]

Love these clips So my question is, is there something we SHOULD buy for this perceived problem? If it even is a problem. I currently have a brennenstuhl block, with a regular fuse and apparently a netfilter in it. Costs 40 euros. It is mainly for convenience and surge protection. And no audible difference whatsoever. Curious about your opinion. Txs

[@MachielGroeneveld]

Hope Amir will look at the power cords and power conditioning from companies like isotek

[@garthhowe297]

That was well thought through. It is odd that a device designed to clean up your 60 Hz AC, only filters above 500 Hz, I believe you said.

[@pomonabill220]

I would LOVE a teardown of this snake oil product! Also, the mains stepdown transformer in audio gear, assuming a linear power supply, cannot pass high frequency, so it is acting like a low pass filter just by design, and not passing noise from the AC line. WOW! The amount of false advertising and snake oil that is pushed boggles the mind!

[@paulweston1106]

Reminds me of those devices that are supposed to cut your electricity bills or those devices you add to the fuel line on your car to save fuel; which of course don't work.

[@geoff37s38]

I had four of those fuel saving devices fitted to my car. I had to remove them because the fuel tank kept overflowing.

[@MrCat-rk9ir]

So true. I bought one just for the heck of it. It does nothing. Psaufio even believes in those very expensive speaker cables.

[@berkut6313]

By Amir’s Hammer, what a savings (you made us do).

[@tonykindred520]

Thanks Amir.

[@DrLoveQc]

Amir I love your channel. Such fresh air in an audiofool world full of gimmick where cables are more important then the gears hehe. For the test I wonder if the transformer used for the test could have filter some noise? Dont get me wrong Im not into snake oil suff at all. But using a resistors voltage divider instead to lower it for the scope would be great to see if the results stay the same. I had issue in past with noise and a low impedance xfo was able to filter it so thats why Im asking. Maybe adding noise in the AC line with good old ballast and LED lights could show even more if its working or not.

[@FluxCondenser]

You’re talking my language about debunking magical thinking in the audio world. Fantastic stuff. Subscribed.

[@NinJa-yg7kh]

i love the blinking light... im a sucker for blinking lights.. im buying one... i love your channel

[@darthbubba866]

Might be interesting to measure the effects of AC mains filters on equipment with plain old linear power supplies. My local power company leases them to you to clean up powerline interference for the whole house (meaning that they are admitting to supplying dirty power.) This is separate from the line spike and surge protectors they also lease to customers.

[@johnreed6495]

Lovely work Amir. It is no wonder why the guys at PS Audio have an issue with you and furthered your nomination as the Most Hated Man in Hi-Fi. Can't you let them fool some of the people, some of the time? That little box you debunked turned a lovely profit.

[@Zazpi_Zezenak]

Hello Amir, stunning channel. I was so glad to find you on youtube, i read a lot of your review on your website. I was wondering I it was possible/interesting to make a noise comparison on USB power supply. 1) Switching PS (phone charger) 2) Power bank 3) Linear PS thanks again Amir for the time and effort you put in our education!

[@shiningpath3430]

What is surprising is that it is some of the "reputed" brands that are manufacturing and promoting such devices. This casts serious doubt on their ethics and thereby quality of their other products!

[@AudioScienceReview]

Yeh, I was talking to another company that makes stuff like this and other bits that work. I tried to emphasize how bad it makes them look even with respect to their valid products. The person did not want to hear it.

[@travis1240]

The trouble for audiophile companies is that they need (or think they need) very high profit margins. You can only get to those profit margins by going well past the point of diminishing returns. Once you do that it's only a slight hop over to make products that are pure bunk in pursuit of the same profits.

[@indopleaser]

when i saw this for the 1st time was blown away.

[@vitalii1372]

Any company who sell such devices treat their customers as idiots. So all PS Audio products should be ignored even if some of them measures well.

[@RealHIFIHelp]

You can have 10x products that measures like this. But if that one same product is a PSaudio, and it then sounds better, then I would still buy it. But I usually find that Gigawatt and Audioquest and especially Isol 8 sounds much better. But I agree, these small products usually don't work, they actually make the sound worse.

[@vitalii1372]

@@RealHIFIHelp oh Jesus! Ok, I’m glad those tech makes you feel better. But you missed the point what Amir talked about

[@ggroch]

@@RealHIFIHelp It matters to me (and Vitalii) if a company is willing lie to sell its products. Many HiFi companies do not lie. I can find great products that fill my needs without purchasing from companies that I already know are dishonest.

[@RealHIFIHelp]

@@vitalii1372 I did not miss the point. This particular product is bad, and so are so many small gimmicky products. You need earth as a minimum on stuff like this, and then a proper powercoupling which you cannot do here because of the design. And if those things are achieved, then it has a chance of actually sounding good. But I am not even going to try products like this, because they are just built badly. The stuff I am comparing it to is 10x better, but also a very different price. And yes to some degree all of this crappy level of gear does change the sound. But not for the better.

[@RealHIFIHelp]

@@ggroch I agree. But sadly that is the standard. Most companies with an investor based model, has to do this type of thing to document progress. I can only assume that a lot of companies making bad products are based on that. Having talked to a lot of audio brand owners. It's a global thing not just an audio world thing.

[@hoschi4202]

Oh, one thing I'm curious to see tested: the claim that you should connect your gear with respect to the phase of the mains outlet. You know, the 'polarity' of the AC Plug if you will. Sounds like nonesense to me, but maybe you could check this out some day... cheers

[@AudioScienceReview]

If the plug is not polarized, sometimes one direction induces less mains noise than the other. I sometimes see this in measurements. The difference though, is not usually audible.

[@venkatagirikotte4019]

More of such awesome snake oil debunking videos, please

[@PapaWheelie1]

We should build a KZbin BS filter. It would blink and light up when watching PS Audio videos

[@mattbastable1942]

Thank you Amir for another great de-bunking video. Would you consider adding teardown analysis to your reviews? I was really hoping for a 'Big Clive' moment on this one :o)

[@AudioScienceReview]

I do teardowns often but devices like this that I don't own, and are glued together, don't allow that.

[@MrAnddre]

Amir, thanks for the video. I have one doubt: What are your impressions/tests done on power regenerators. Do they improve the ac main - meaning do they help having a "cleaner" source for the downstream components or do they add other issues (noise?) into the equation? Best Regards,

[@AudioScienceReview]

I have a PS Audio power regen. Let me formally test it before commenting.

[@MrAnddre]

@@AudioScienceReview fair enough. Looking forward this review. If possible, after the measurements/evaluation procedures, could you please test if the power regen with a phono preamp? The reason I am asking this, and correct me if I am in the wrong path, is that the phono preamp might have a higher gain and should amplify "potential noises". BR

[@isettech]

There are several varieties of AC noise filters. Some actually make the problems worse. Some AC power filters use capacitors to attenuate voltage spikes on the AC line. If they are connected between line an neutral, this is very effective at reducing differential noise, but does nothing to reduce common mode noise. A traditional powerline filter also has capacitors from line and neutral to ground. This does shunt the common mode noise to ground, but here is the kicker, it puts the harmonic noise current into the ground system, which in a sound system is a very bad move as now not all components are plugged into the same ground reference voltage. Ground for a sound system needs to be a voltage reference, and not a current carrying conductor. For more information on the subject, refer the the National Electrical Code under grounding and bonding. There is a section on Isolated Ground for sensitive equipment, such as hospitals. Often referred to as Hospital Ground, the important thing is you do not plug in any device with high ground current from a noise filter into a hospital ground. This includes VFD motor drives, Desktop computers, etc. To properly review AC power filters, the amount of coupling into the ground needs monitored too. When sweeping the filter to test it, test each leg referenced to ground, and test the differential mode of the filter between line and neutral. A good filter contains the following.. MOV between Line, Neutral, and Ground. Input capacitor between Line and Neutral only, a bifilar transformer, and an output capacitor between Line and Neutral. Industrial equipment has additional capacitors to ground, and are used for RFI, EMI reduction at the source, but is not to be used on the same circuits as sensitive equipment. The VFD drive on your CNC belongs in the garage/shop on it's own circuit, not on the same circuit as your sound system. A proper noise filter is always a pass through device with a bifilar coil in line with the equipment, not a stand alone plug in module. A proper noise filter is as shown here. forum.arduino.cc/index.php?topic=119313.0 They can be purchased as part of the AC socket for your equipment. www.alibaba.com/product-detail/IEC-Socket-Type-Single-Phase-AC_60477587273.html

[@TheLkdude]

Thanks, Amir !!!! another great video, I was wondering about these types of filters like IFI AC Purifier / Greenwave .. I believe these could be similar.

[@Gnao_fuzz]

I have always thought that it is much easier to filter the DC well after the power supply than to insert large and bulky filters on the AC side ... what do you think?

[@mobilemcsmarty1466]

thanks for the detailed confirmation of what we suspect! and when it comes to audio, suspicion is your friend. I'm surprised PSA would damage what reputation they have by putting out such a trinket. similar bunk devices are seen around the Interwebs, maybe claiming greater efficiency for your refrigerator or A/C. when I heard "gets warm," I'd like to add that it must be drawing power beyond blinking the LED. that's power that you will pay for too at the meter every year that you're foolish enough to set this mini-heater and forget it.

[@Antoon55]

Oops, I bought a PS-Audio powerplant last year. This makes me wonder how that would measure..

[@AudioScienceReview]

I have one of his older units which I plan to evaluate.

[@hello-pq5pj]

The power plant is a completely different beast in how it works. That will definitely filter out those nasty frequencies. Don't be worried. You have a good power filter

[@geoff37s38]

@@hello-pq5pj but does it improve sound quality? This is the only relevant question.

[@hello-pq5pj]

@@geoff37s38 I'd say it's a high end treatment and would need a very good System that had a dirty power supply to hear a difference. I know a guy who listens to his stereo a 2am because he believes the power line has less noise at that time of night and his system sounds better at that time.

[@geoff37s38]

@@hello-pq5pj I too think my system sounds better at night. But I know this is a psychological effect. Low lights, more relaxed, no traffic noise, no barking dogs or chirping birds or other distractions to mess with concentration.

[@cornerliston]

Thing is, I'm not sure if this is valid for USA, but in some countries (all of EU I believe) if a company is claiming a product benefit and it does not deliver you have the right to send it back with full refund no questions asked. It's part of marketing regulations I think. Now problem for many of these kind of products is that they don't show us any data. Therefore they can claim all is working as it should. Although I still believe that if you claim anything you should be obliged to show data proof. Unfortunately this is still to be regulated.

[@glenncurry3041]

You mention using a step down transformer to measure the mains noise? Was this an AC transformer like one used in an amp PS? An iron I/E core? Toroidal? Most standard I/E step downs would be band pass filters. Many even worn that for a 60hz unit 50hz can cause overheating because of internal eddy currents from nontuned frequencies. You are not looking at the actual AC from the mains. You are looking at an isolated output based strictly on the magnetic coupling between windings. So one has to wonder where all the harmonics and other signals are being generated from?

[@skip1835]

Interesting test Amir - I'll say up front that no, I wouldn't, nor have I tried a Noise Harvester in my own system - I'm wondering about your explanation regarding "cleaning up" AC - which is really not what the harvester is about, at least as I understand it - and as you pointed out, to actually clean up AC one would have to drag out some heavy artillery, which, as most of us know is also offered by PS Audio but in a much higher price bracket, to put it mildly - - my take on the Harvester is that it might be capable of taking some of the RF noise out of an AC feed, not somehow change for the better the AC waveform itself and it's harmonics - and in that realm, for sure results would vary - I know your response would probably be that we can't hear RF so how can it degrade the sound - I wouldn't debate that because I don't actually know of my own knowledge, but it does make some common sense that RF noise probably does make it's way into the system and so my common sense tells me that a system would be better off just processing musical signal alone, that is, sans at least some of the RF. I appreciate and like that you offered up a listening test - - that's great and it immediately grabbed my attention - - but I was left a bit disappointed in that, beside the "professional DAC" you didn't describe your other playback items - - I can speak from my own experience that a 300 dollar headphone is not reference and I'm guessing you're not using a reference headphone with a 1K DAC and if that's the case, I wouldn't expect you or me to be able to hear a lot of differences, even in similarly priced playback gear let alone an add on item going for a 100 bucks - - regardless, I appreciate you offering the listening test with your measuring, please continue to include that test - although I would like to know that your using at least entrance level reference playback gear - however, it wouldn't surprise me if you'd want to claim or measure that reference gear is a myth too. You can delete my comment - my passion is that I feel like your giving a lot of new audiophiles the wrong idea and to "poo poo" someone that claims an improvement with the Harvester is unfair and unwarranted. And - - - the expression: "getting it right 10 times of 10" is stupid - if I changed out your "professional DAC" with another one that's comparable 10 times do you think you would get it right 10 times? Never, so come on my friend, that kind of a test doesn't mean that perhaps your "professional DAC" isn't better, it only proves that you can be fooled and so can all of us - doesn't mean that there are no differences, with some of those differences for the better - regardless of my criticisms I really do like and appreciate that you goal is to shed light on "over-hype", I'm good with that and will continue to watch your channel - - thanks for letting me express my opinion.

[@montynorth3009]

RF interference won't get into your equipment via the mains plug, just consider the choking of the mains transformer coils and shunt capacitors.

[@skip1835]

@@montynorth3009 thanks Monty - I appreciate you pointing that out

[@Phos9]

So the light blinks when it’s hooked up to a power strip with nothing else connected? What I want to see is compare its level of blinkyness when connected to mains to a 60hz signal coming out of the audio precision analyzer. My money’s on this just being a box that rapidly blinks an LED

[@bluev2srt]

I use it to determine when I have a bunch of noise in my power. When the microwave is used and other devices is blinks like crazy. One dissapointing thing is the unit blinks more in my expensive furman power conditioner then just power from the outlet...

[@cameronwilson8561]

Great review, I’d love you to pop the cover open to see what’s actually inside

[@mikebeacom4883]

I’m thinking I’d see more improvement with $1000 of acoustic treatment than $1000 of harvesters and cables.

[@SqueamishPuppet]

Thanks almost bought one to try it. Glad I didn't.

[@JohSno]

Thank you for sharing.

[@herrtrigger7220]

PS Audio admits they 'voice' new gear on their one-of-a- kind Infinity speakers with equally unrealistic and impractical amps. It's like the Emperor's New Clothes over in Boulder.

[@njm1971nyc]

Paul McGowan seems like an affable kind of guy in his videos, but basically he's fleecing thousands of wealthy idiots for all he can get. In some ways I can't blame him... Audiophools need to feed their expensive habit somehow. Personally, I'm too honest to sell BS products, I couldn't live with myself, but McGowan, Darko, Beekhuyzen, et al. are a different breed. Earning a living from the stupidity of others.

[@andydelle4509]

Well the science behind this product is solid. Yes an LED being powered off a circuit tuned to a specific frequency band will consume some of that energy. And another fact, if someone threw a handful of file folders out of WTC#1, that reduction of weight did in fact delay the collapse. See the issue here?

[@lucianp87]

This is so entertaining!

[@chrisharper2658]

Ah, very good Amir. In the not too distant past, Ask Paul brought up the so called issue of having DC on your AC line and how this some how effects your sound because the believers think that this must saturate your power supply transformer. Paul said they use to make a device to fix this but no longer do. I Googled it a found someone who had one posting on an audiophile message board. Turns out, the same PS Audio filter had been resold at least three times on the same thread. I think the device originally sold for $500. It was like a hot potato. Initially, each person thought it helped but after a while they determined that it didn't and wanted to recoup there loss. And there seems to always be another sucker willing to give it a try. I have no idea what they're trying of fix. I posted about it on Ask Paul's video and someone actually said in response that 'DC on the AC line is an actual thing'. I find it unfortunate, when looking into the belief of 'DC being a problem with AC power', that it may have started with Nelson Pass. I found the circuit on-line somewhere that is supposed to 'fix' the problem. Its total nonsense. Keep up the good work!

[@chrisharper2658]

@Douglas Blake I know that and you know that but the Paul followers just blindly follow. When trying to understand what the heck they were claiming, they seemed to be misrepresenting some distortion of the AC sinewave. I know that the input power supply just filters that out and it would have to be awfully bad just to make a transformer run a little bit warmer but that's not what they are claiming, they're saying DC. The impedance of a pole transformer is way too low for that even being a possibility. Cheap appliances with half wave rectifiers are one claimed source of such imbalances. That would mean that these 'experts' can hear a few millivolts of non-symmetrical AC on their stereos. Boy are they good.

[@lapetitemortbis]

I would be really curious to see a review from you of stein music products/tweaks.

[@kilgoretrout4461]

Keep up the good work buddy!

[@kevinwest1607]

I'm ready for some of these butigue speaker brand vs $500 speaker's comparison.

[@phantomplastics6582]

Cheap to buy an Entech Powerline and EMI Noise Analyzer which allows you to hear the AC line contamination. Makes it simple to hear if your filter is working or if your cables are giving off a signal.

[@johnsweda2999]

I wanted if the isotek is any better? they make one of those. just use a 1uF safety cap do most of your filtering for you

[@kuronekosan2830]

I have a question As u said harmonics filter for dc is dirt cheap So i was wondering Firstly ofc if i use ac to dc to power up the board then use dc to ac pure sine wave inverter which was sockets on it..can i connect my automatic voltage regulator to that then connect my av reiever to it ? Will the filter work ? Or should i eleminate the avr and directly connect my reciecer to the inverter ?

[@byondo]

the 500Hz filter actually makes something: it feeds a pleasant "visual" signal to the LED 😉

[@Gersberms]

If you absolutely must remove AC noise, won't a rotary phase converter be the final answer? Mechanically creating clean AC from dirty AC, I think that may be something audiophiles can appreciate!

[@elacombe75]

These videos are great, keep them up! I.would be curious to get your thoughts on power conditioners in general, or having dedicated lines to your system. To your point, the ac/ dc conversion and filtering in audio devices would also render these moot as well?

[@AudioScienceReview]

Thanks. Have a power conditioner video coming up soon.

[@Benvos]

Do you have any recommendations of products that do positively improve audio systems? I enjoy finding out about what doesn’t work so it’d be good to know what does.

[@AudioScienceReview]

Nothing I have tested in this category provides useful value for audio.

[@ZeroDividesByYOU]

This reply is pretty late, but legitimately the only things you can do to improve your audio quality are such (in order of priority): 1. Good-measuring speakers and/or headphones 2. Amplification/converters that suite your playback system (proper amount of power for high/low impedance headphones) 3. Quality (not overpriced) cabling especially if you are in a very noisy RF environment. Balanced connections (XLR mono channels for example) will help remove noise from longer cable runs to speakers or headphones. That's pretty much all you can do.

[@fwabble]

Fantastic as always

[@thomaswipf7986]

Please do the PS Audio Power Plant. I'm considering buying Power Plant.

[@herrtrigger7220]

Wow, McGowan's Noise Harvester video is right next to this one. Delicious.

[@nicksundby]

Outstanding video, what a superb channel

[@pfcompany885]

What about ISOTEK EVO3 ISOPLUG? Same snake OIL?

[@ssl3883]

please help review ifi ac purifier also

[@SkeledroMan]

You tried the iFi iPower X? Seems like it haw some nice technology but who knows if it actually does anything.

[@SkeledroMan]

It would be interesting to see if it can do anything better than an iPhone power supply or a linear power supply like the topping p50

[@AudioScienceReview]

I have tested the previous generation. It actually added some mains noise versus not using it! And it did nothing to improve the output of audio products I tested with it.

[@SkeledroMan]

@@AudioScienceReview can't find the results on ASR. What thread are they in?

[@SkeledroMan]

I can find the measurements of the DC iPurifier but not of the actual power supply, the iPower or iPower X

[@ebarbie5016]

Please do a video review of their Direct$hit DAC

[@ron521]

FWIW It gives you a visual indicator of the presence of electrical noise in your home.

[@kurb1980]

If you think this is bad see Amir review if the PS DS DAC it’s so noisey it looks like dirty mains 😩

[@AudioScienceReview]

:) I should do a video on that.

[@ericharrelson2045]

@@AudioScienceReview I'm actually waiting with much anticipation for this one.

[@jean-paulschweitzer6211]

Do you don´t need a LISN for the measurements?