Impact of AC Distortion and Noise on Audio Equipment Fidelity

[@ScottGrammer]

Well done, sir. Years ago, I started answering questions asked of me by audiophiles about such things as $1,000 AC cords and power conditioners, "Shun Mook" disks, and other such snake oil, by saying, "If someone told me that painting my car yellow would make it go faster, I would not have to paint it to know that it's not true." It is good to see that you're willing to "paint the car to know it's not true," and show the results to the world. The only problem is that when you're dealing with true believers, you're not dealing with rational people, and your logic and science will not be appreciated or accepted.

[@AudioScienceReview]

Thanks. True believers won't believe. But there are so many people joining them anew that we can impact them. As best I can tell, people are responding to data which is great.

[@chrisvinicombe9947]

Everone knows red ones go faster 😀

[@homerjones3291]

@@chrisvinicombe9947 Yep. And insurance companies charge more for red cars, and police have monthly quotas for writing speeding tickets.

[@66rabidmonkey]

@@homerjones3291 not true, urban legend. Only the DMV knows the color of your vehicle. insurance companies don't use vehicle colors to determine rates. They'll use odometer, year, make, model, sub-model, and VIN, and safety/security features.

[@Burevestnik9M730]

The only thing that remains to be debunked are ben Duncan's measurements from 1995. These were time domain measurements. Any device based on FFT (all measuring devices) are integrators, that's what frequency domain is. Duncan considered all cables to be energy storages where signals travel back and forth. Now, these patterns could theoretically be different while all showing the same frequency domain measurements.

[@jagkahlon]

Amir by doing this you have helped the audiophile community by helping them avoid falling prey to marketing and throwing hard earned $$$s down the drain. BTW keep the videos going, learning a lot.

[@AudioScienceReview]

Thank you. Will do.

[@RennieAsh]

It helps some, but many will still believe and buy these random devices :)

[@vdochev]

@@RennieAsh This may help someone who is just getting into the hobby. Try explaining this to someone who is hardcore in with their conditioners and mono blocks and whatever snake cables and cryogenic cable raisers that they paid a fortune for - not gonna happen. However, these videos do help those who listen and are not hypnotized.

[@christopherkent6512]

Folks are still going to buy them because they believe what they are told by the manufacturers/sellers.

[@danielgeiger7739]

Superb! The dirty power generator is a stroke of genius. Even my VERY limited electronics comprehension can see that a 4-diode Graetz circuit with some capacitors can flatten the dirtiest AC. Thanks. ooops, you did again!

[@firuzpulatov7750]

wow, what a subject! All these years I was thinking of buying/building some kind of power conditioner to improve my system. Looks like I was waiting for a proof whether it would be useful, and now I see that it is better to spend money on something else but power conditioning. Thanks to Amir for saving not only my money.

[@whippetgas]

I needed more sockets once so I built a flashy "Hifi Size" box with a shedload of backlit ammeters on the front and some cheapy chineseum power filters inside just for the sake of it...A Colleague of mine spotted it and asked me to build him one, he reckons it "really opens up the soundstage" whatever the hell that means. I just smiled and took his money.

[@Burevestnik9M730]

The only use case is to have protection and to have all switches on a single box as many boxes have switches at their backs, which are hard to access

[@alanross3661]

This confirms what I always thought. Thank goodness I saved a ton of money over the years not investing in useless giant boxes.

[@beetleburper9440]

Just jumped into the audio world of dacs and amps it was actually your review that made me pick the topping e50/l50 perfect and now youve just answered another question i had. Thank you so much for taking your time to do this for everyone.

[@fwabble]

What Amir is doing is changing the lives of audiophiles for the better - the ones willing to accept there are people with FAR FAR more knowledge and in depth understanding of electronics and how we hear, those, like myself, appreciate Amir beyond words.

[@DiegoooTech]

Groundbreaking video for those who want to see ofc... Thx Amir as always.

[@AudioScienceReview]

Thank you. I am glad you found it of value.

[@andrewm1894]

Once again my audio setup sounds better each time I watch one of your videos. Thanks!

[@SLCVideoProductions]

Another well done video! The incandescent dimmer mode of the 9801 is a great tool for this. Your have a gift for presenting technical topics- thanks!

[@l_jin]

Bravo!!! This test results really tells something to all of us. Just buy a good gear!

[@leekumiega4919]

love your video's and this one confirmed what I already knew because years ago I bought a Carver "magnetic field coil " amplifier where the input of a rather small power transformer ( the magnetic field coil ) was the output of a triac that kept the voltage of his power rails constant and at low volume only a fraction of a chopped sine wave fed the transformer but the output when when rectified and filtered made no difference as his amplifiers measured and sounded good .

[@MiDnYTe25]

I'm a simple man. I see Amir, I like the video.

[@freak-zd4wm]

Great test👍 Thank you for your time and work!

[@MrAnddre]

Thanks for your input, Amir. Best Regards

[@AudioScienceReview]

Thank you Andre.

[@audioreinforcementconcepts3537]

Very interesting test, that proves well what I always felt, and that these AC conditioning equipment does'nt make any relevant effect on sound, even is AC power is very distorted. In some country in Europe the mains plug can be reversed in the AC socket and some advocates this as "in phase" or "out of phase" mains connection. It will be interesting to hear from you about it with some measurement. Thank you.

[@mikegoddard7354]

We love Amir, and "they" hate Amir. "BUT YOU CANT MEASURE WHAT'S HAPPENING WE DONT HAVE THE TECHNOLOGY!" Maybe that's why company's like Audio quest justify not posting any measurements, at least finally they'll have something to say which is honest and truthful.

[@shean-koklim4197]

I knew it! just that I dont have the financials to purchase the test equipment to prove it. Thanks for debunking the dirty power myth.

[@bigherb]

Yay more interesting stuff for me to watch 😊

[@IsmaelMartinezPR]

Power conditioners are a great profit center for brands and dealers. They are simple to make -in theory- and are good to pay the bills. A guy with spending cash goes to the High end audio store, the dealers tell the un-informed client."You mean to tell me you are buying $9K in amps and you are not going to get the $900 - $1,500 power conditioner". They also say "careful with brown outs", and "the AC mains do you trust them with your new amps", BOOM sold. They may even throw in a discount so you feel even better. At 50% profit that's $700 bucks to the bottom line. Now you have it home, you show to your friends, say "hear that difference, see Darko was right after all". Cycle repeats. Now comes ASR and debunks Thousands if not Millions of $$ in gear sales of these un-needed equipment of what we have suspected for years, they don't do squat. They only empty your wallet. Jajaja Amir M is going to be really popular with McGowan.

[@AudioScienceReview]

Exactly right. The margin in the thing you are buying could even be negative and he make up for it with these boxes, cables and extended warranty.

[@MadAudiofficial]

Crazy, AC with so much noise and no Impact!!! Great video u answer to a big doubt that I had, there is really no need to use power regeneration to convert AC to DC to AC and than again to DC with our equipment!thx Amir

[@johnsmith1474]

Brilliant! The truth in the face of endless obfuscation is so refreshing. Love the upbeat tone and light heart too.

[@SteelBlueVision]

Amir: No one has power distortion this bad! 1000W Halogen Family Room lighting with a conventional efficient TRIAC based wall dimmer switch: Hold my *buzz*eer, I'll show you real world dimmer noise on your mains 6.5A shop vacuum has left the chat...

[@luca12957]

As expected. I'd like to see the same experiment done with an usb powered dac very much. The A90 has an internal power suppy, instead the dac relies on something else to provide the conversion to 5v dc, so maybe a good power supplier works better then a cheap usb charger, although i suspect the changes will be just slightly less noise, well under threshold of hearing.

[@amirkessner8184]

Hello!! Thank you for sharing the tests. It seems that only one aspect of AC distortion -- harmonic -- has been tested, but with a constant amplitude/voltage. Can you please test also what happens with significant volume fluctuations?

[@michaelamorello3348]

A 60hz AC signal already has alternating current, and therefore alternating voltage.

[@amirkessner8184]

@@michaelamorello3348 -- As we're discussing alternating current, "voltage" is used in AC terms, which refers to the amplitude of the current waves, which, in the case of the tests that have been performed, was constant.

[@moshet842]

@@amirkessner8184 That's because we are measuring RMS which is what matters

[@amirkessner8184]

@@moshet842 -- this is undoubtedly an important part of what is relevant, but arguably not all. In real life, AC fluctuations are not limited to adding harmonic distortion to constant amplitude and frequency. The amplitude can vary too, and theoretically even the frequency, but I'd assume the latter is rare

[@jefierro]

Very insightful and clear, the idea of cleaning ac lines reminds me of the 60s, when ac to dc converters realy where not good. Nice to see you back Amir.

[@JesusMartinez-mk6fc]

Bravo once more Amir! This video backed by simple and clear empirical evidence is a landmark demonstration for this category of audio gear. I've never seen a review that tackled this subject from an objective and scientific electrical engineering perspective like you just did. I was considering purchasing very expesive power regeneration gear a few years ago but I decided to delay the purchase sometime in the future due to the high cost. You've just saved me and hopefully many others a lot of money that can be better spent. Thank's a million! 👍😀

[@AudioScienceReview]

Thank you Jesus. This was an idea I had years ago and should have done it earlier. The concept of an AC generator is so alluring that it is hard to resist without hard data.

[@beardedgaming1337]

the most frequent issue i find with audio equipment (more average consumer stuff) is noise through the output/input stages when not using preamps. so having a surround receiver and adding an external amp (maybe for sub or fronts) and the new amp (or other electric device like a air conditioner or sump pump in the house) will cause buzzing or popping on the speakers. ive also seen mouse movements on a PC that is connected to such equipment cause rapid clicking/popping in speaker systems.

[@JurajHatina]

Thanks again Amir! Well done and explained.⚡️

[@AudioScienceReview]

My pleasure. Thanks for watching.

[@dfknyc78]

Amir, awesome awesome experiment. My only feedback is that, there is one power issue that I know of which does legitimately warrants a power conditioner and that's DC offset. I have it once and it caused the transformer in my amp to physically buzz, though no effect on sound quality. BUT, these silly filters won't work to block DC offset, you would need something like the humdinger or an Emotiva CMX-2 (which both costs less than $150) or an isolation transformer or a quality double conversion (rectifier to inverter like the PS Audio regenerator or a much cheaper version, a double conversion UPS).

[@AudioScienceReview]

Yes, that can indeed happen. As I mentioned in the video, if you have a real AC problem, then some AC solution may be appropriate. The problem is that 99% of the people buy these things when they don't have any audible problems.

[@dfknyc78]

@@AudioScienceReview Totally agree, the con man preys on the ignorant. Much much appreciate your campaign to educate the unknowing (myself included). We, the community, bestow the title of Snake Oil Slayer on you! In all seriousness, I once used to be an audiophool and spent money on cables, hard lesson learned. But your forum and channel has really helped.

[@sviktor4]

I think Amir should have tested at least one equipment with transformer in it, switching PSU shouldn't have problem with dirty power, you can feed them AC or DC they should produce the same output. The buzzing sound is annoying, but also can loosen up the coil, generate more heat and drops the efficiency of the transformer, so you loose performance, if someone using a smaller Power Amplifier (20-60W) near the maximum output he can loose base performance under 100Hz in the EU and 120Hz in the US, not to mentioned cause buzzing sound especially in cass A amp, but it really depends on the amp design. I don't think 300-500W amplifiers are impacted much beside the transformer buzzing. A couple years ago there was a nearby constraction and every day about 11 am. my amp transformer horribly started buzzing, so I just simply turned it off.

[@adrianmorrish8494]

what you say makes complete sense even without your testing, thank you and my wallet thanks you, so this would also apply to and not to pick in them the ifi devices then, which is strange because some people say they caused the sound to degrade which again isn't possible.

[@garganega]

Any difference between fiber optic/residential 5G/coaxial on streaming quality?

[@josephreynolds6844]

Was just in an online discussion, on a hi-fi forum, with a gentleman who claims great benefits from changing out his power cables, with an esoteric power cable brand. It's parallel to banging my head on my desk.

[@SwirlingDragonMist]

Powerful and eye opening, So glad you did these tests. I would like to request a follow up that looks at ultrasonic spectra when these power filters are introduced. Sorry if that seems like an annoying request, I really wish I had the gear to look myself. Thanks either way.

[@Benvos]

The question about power also comes in the form of dedicated power lines - does this make a difference to audio performance?

[@FOH3663]

Yes, it can. A dedicated circuit can make a difference in high power, high demand scenarios whereby voltage drop is encountered. For high performance audio systems, best practices include a dedicated circuit with an isolated neutral and ground all the way to the panelboard. A dedicated circuit simply means that the breaker feeding that outlet is solely supplying that outlet. This avoids potential voltage drop choke-point scenario of a high amperage dynamic swing atop the circuit's baseline load, thus exceeding the branch circuit's wire ampacity ... eliciting I²R losses or voltage drop. Given the option, always up-size the wire AWG supplying the dedicated outlet feeding a high performance audio system. It's best if the Neutral isn't shared either ... proceeding unbroken all the way to the panelboard (an intermittent open neutral can be catastrophic to equipment, allowing 240v across any loads plugged in). With any ground wire, it's best to possess a dedicated, low impedance path to ground. Thus; an up-sized, dedicated home-run, unbroken all the way to the panelboard is best.

[@ebarbie5016]

It's actually 35 out of 180 degrees. Dimmers uses Diac based AC control (delayed firing angle). The waveform looks more distorted than it should be

[@johnsmith1474]

Your avatar image looks like a distorted mind.

[@samhalsey5051]

The home I’m moving to, I believe is near a transformer and apparently the power almost never goes out when most of the rest of the town does. Will that possibly mean the power may be cleaner, than normal?

[@jimomertz]

I would have expected you to test the Audio Quest Niagara with the dimmer AC signal. It should give minimal reduction in high frequency noise, even though it won’t make any difference ultimately.

[@MrSmokingsanta]

Do you have any measurements on the California Audio Labs Sigma DAC? It is my first DAC that I bought in 1995, and I still have it today. It sounds very different from any other DAC that I've owned, and the difference seems to be larger than what the specs, published measurements, and distortion figures would suggest. The user's manual quotes very flat FR and low distortion, and I believe Stereophile had also published the measurements back in the day, but it sounds night and day different from my Topping D90 and Emotiva DACs that I've done numerous A/B on before. I've always been curious why that's the case.

[@MrSmokingsanta]

By the way, the output is around 3 dB higher than most DACs I've compared with, but even after adjusting for the output level, the CAL Sigma II still sounds very "thick", which made me suspect that it is loaded with distortion, but the distortion you showed in the video is still quite low compared to many state-of-the-art power amps.

[@AudioScienceReview]

I do not beyond what you saw there. One channel started to fail after that testing so I just put it aside. When I have time I will see if I can repair and test it.

[@thisrocks]

The only noise I’ve ever had is when I plugged my amplifier into the same circuit as a PowerLine adapter. I first thought the unit was faulty but trying it in the store resulted in no noise, then I was sold expensive cables and still the noise was there but I had no idea what the culprit was. Then I eventually got a UPS to isolate the amp to its own circuit and it fixed it, doing that gave me the aha moment confirming the PowerLine adapter to be the cause. As a benefit I finally had an excuse to own a UPS and have enjoyed no LAN drop outs and a “black background” (lol) ever since when listening to music.

[@AudioScienceReview]

Yeh, those adapters can be noisy.

[@quananginh9446]

But doesn't the amplifier filters out AC noise with its power supply filter? How come the noise from a different device get into the signal path?

[@thisrocks]

@@quananginh9446 it definitely doesn’t. Whenever I use my mac, or my iPhone or my projector, anything plugged in to the wall, with headphones or when loud enough through its own speakers you can hear the noise. Put the device on a UPS and noise gone

[@quananginh9446]

@@thisrocks I guess the problem is about grounding. Your amplifier probably uses unbalanced audio inputs and its power cord has a 3-pin plug.

[@thisrocks]

@@quananginh9446 I have had devices like my PC plugged in with grounded power cables and when I plug my headphones into it, the same noise. It’s not a grounding issue. If you would like to help solve it, please feel free to buy some Ethernet over power adapters, and mess around. If you come up with a solution you can sell it to me.

[@hdmoviesource]

Great video. Now the big question is... Does PS Audios Power Regenerators, the P15 or P20 PowerPlant have any impact? Because I believe that produces the absolute cleanest power you can get. You could say, where do we stop, but if the P20 Powerplant has no effect then I'm 100% on-board with this idea that they have zero effect.

[@andrewskaterrr]

The tests he did were more extreme than the potential tiniest difference between his AC unit and the P20. If there was going to be a difference, you would’ve seen it here.

[@hdmoviesource]

@@andrewskaterrr I think you're right, it just my kind wants to test everything 😂

[@DescartesRenegade]

He covered your question at the end of video. The device itself converts AC to DC, in doing so, it removes all noise. Essentially, doesn't care about quality of power at all

[@bahathir_]

Why not just use battery. :) No mor large AC power filtering or complex AC to DC rectifiers. AC from main inlet is very convenient, but are there any modern Hifi devices which are run on DC power only? Any thoughts or opinions are welcomed. Thank you.

[@RennieAsh]

I guess you could run some of those class D modules off of a battery system, and it would last well due to the efficiency. Send audio from a portable player , full battery powered system :)

[@garynichols1502]

Great video and test!

[@steabert]

What is that AC spike above 50kHz?

[@davidschultz3585]

The type of distortion used seems almost designed to not do anything. Why? Your typical power supply uses a bridge rectifier and filter caps. This draws current from the line only when the diodes are forward biased. Usually only near the peak of AC cycle. (Causing noticeable distortion in the AC waveform.) So those triac switching steps vanish. Better would be to insert noise/distortion at the peak of the cycle. A consequence of this is that if AC line noise/distortion were a problem, the effects would have a very strong 120Hz component simply because of this switching action from the diodes. On the other hand, there is one device which is more sensitive to AC line problems and that is the belt drive turntable. But even that has a significant low pass filter in the form of the drive belt and platter mass.

[@jeffs.2752]

Thank you. I was hoping you would do this test.

[@xavierng3109]

What if the ac generator feeds into an amp with switching power supply?

[@michaelmuetstege2965]

Nice video Amir! I have a question, when I turn my TL light on in my mancave I hear Some cracking noice from my speakers What shape does that voltage have? And why do I hear it in my speakers?

[@topalofff]

Hello. Low frequency noise can be easily filtered by capacitors and linear PSUs. But what about high frequency noise about hundreds of kilohertz coming from loaded cheap switching PSUs without internal filters? Or inverter welding machine in near? I played with Topping D50s, which is sensitive to power quality and noticed that clean and good isolated from mains power supply can make an audible improvement. Unfortunately, i haven`t good equipment to measure.

[@MrXyzasdf]

A properly engineered product will account for a "dirty" power source. Furthermore, an excellently engineered product will have cascading power supplies. Switching power supply > low noise linear power supply > ultra low noise linear power supply.

[@topalofff]

@@MrXyzasdf, for example, I've tested Soncoz La-qxd1 with different power supplies and noticed, that DAC has lower noise floor with linear power supply. Besides, in terms of noise resistance it is horrible, despite LDOs and other goodies on the board. I don't know yet, how PSU noise can influence DAC. I'll post some measurements in ASR forum later. That test means, that it is better to use linear power supply rather than switch PSUs. Because you don't know how resistant your DAC to PSU noise.

[@scottgordon1721]

Amir, I have a question if an amp advertises that it is capable of eliminating jitter and noise are they important features to have or just marketing hype? Also I asked the site Audio Adviser if THD of .5 is bad as so many amps have THD stats of .oooX the response was there were THD wars in the1980 that resulted in poor sounding amps. So how important to musical sound is low THD and is .5 THD too much,a warning sign of to much distortion to sound good? As you can tell I'm new to all this but the THD stat is perhaps the one universal stat. that manufacturer's list on their spec. sheet. Regards and thank you for your very informative show it does the average audio Joe a great service.Thank you

[@frankiep8262]

“A fact’s a fact from Rome to Nome, boy.” (Rush, “Hold the Bones.”) Couldn’t resist. ;-)

[@cxmxc]

In your hd58x review why is there a peak around 5-6khz on the right Chanel and on the left channel looks like the drop measurement?

[@AudioScienceReview]

Hard to know. Often is due to alignment not perfectly matching on the test fixture. Or the drivers are slightly different. Headphone measurements are approximations so best to adopt a high level view of them. I certainly don't try to correct for such differences.

[@cxmxc]

@@AudioScienceReview oh 👍 thank you for the response.

[@Soundfreeek]

Thanks Amir ! Just decided to sell my PS Audio P10 after watching this video ! 😂😂😂 As always, awesome video !

[@toneysunny9283]

will isolation transformer cut down some ac noise

[@AudioScienceReview]

I will be testing one soon. For now, they can filter higher frequencies but that tends to not usually be the problem.

[@albertyeh9793]

@@AudioScienceReview Partcularlly the differential power transformer that generates +55v & -55v to cancel the common noise?

[@Joseph-Lau]

Thank for such interesting experiment. But how about some dirty AC power which has noise from power line Ethernet?

[@Edwinvangent]

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

[@AudioScienceReview]

In general yes. With USB the DAC clock is in charge and PC is slave to it. As such, there is a lot less sources of jitter. With S/PDIF, it is the master clock and the DAC has to chase it. In addition, USB supports much higher sample rates than S/PDIF. There is a case where S/PDIF is superior and that is when it is optical (Toslink). You get full electrical isolation which eliminates ground loops if you run into that.

[@Edwinvangent]

@@AudioScienceReview Wow, first of all, thank you very much. most questions never get answered, and this is already the second answer I get in a few days, thx !! And I do have an optical SPdif and switch from on to the other, that about the clock is good to know (will never forget that) so when it's optical it's the better choice because of the ground loops. If I may once I heard from (also) a tech guy (radio recordings etc) who said, if you have balanced the whole chain it is the best choice, but if there is change from balanced to RCA (and perhaps back to balanced, you will lose 6 DB of ....... the last part I forgot what he meant to say. do you recognized what he was trying to say and is he right about the conversion to RCA to/and back? And therefore don't do it and when source is RCA stay on RCA.. thank you again :-)

[@Edwinvangent]

there is another guy you should check him out, you will be friends I am sure. on youtube his channel is called " goldensound " or link kzbin.info/door/J0oW8D5z_IiFc7w46JJEuA

[@prateeksamuel8603]

Capacitors do really well with cleaning the power. And yeh rectification helps too. Wow great video sir eye opening for me and will be for many people aswell. 👍👍👍👍👍👍👍👍👍😲😲😲😲😲😲😲😲😲😲😲😲

[@fjchiu7489]

Now I can see how important the capacitors are. Will multiple capacitors better than twin? How about use dual rectifier bridges? is it better than use one bridge only, Mr. Amir?

[@DavidMoonWainwright]

I'm curious if reducing the voltage down to 110 or lower (brown out) would affect the audio signal?

[@AudioScienceReview]

That will only impact class A/AB amplifiers with unregulated output voltage. There, the lower voltage will reduce total available power. For everything else, the voltage is regulated and would not care at all.

[@petertreyde3212]

Thanks for clarifying that. Another excellent presentation. I live off grid and, according to the manufacturers of the inverters used to generate AC for the house, I have cleaner AC power than most people get who are grid connected. I was feeling smug about that. But actually I am quite relieved to know it makes no difference, and I need not go chasing any further AC power cleaning solutions.

[@shayan-gg]

i hear a pop noise on my zen dac when my mains devices are turned on or off, even my doorbell. Any cheap solution?

[@AudioScienceReview]

The only cheap solution would be trying a different DAC. Troubleshooting these kind of problems is very, very hard.

[@stefanthuering6456]

Yeah, I wish the test would also have been done with spikes on the mains.. do those go through to dacs or amps.. ?

[@mariorinaldi7612]

Thanks for this video Amir! Just one question, as I am completely new to this topic. Do these results apply to linear power supplies? Are they non affecting our gear in any way compared to the normal switch power supplies?

[@bluelithium9808]

Thirty years after Julian Hirsch came to the same conclusion, this seems to be news again to the current crop of golden eared ones.

[@AudioScienceReview]

The pendulum has swung so far to the other extreme that nothing needs to follow the laws of engineering, science or anything for that matter. If they can imagine it, it must be true. We can tell them this is wrong but they don't listen. Hopefully data like this convinces people to not join them.

[@IsmaelMartinezPR]

I sometimes feel that Amir M is the Julian Hirsch of our time. Keep it up.

[@fredw61]

@@IsmaelMartinezPR And that is a good thing?

[@IsmaelMartinezPR]

@@fredw61 Absolutely, always testing before his opinion. that's why.

[@skargardsdoktorn6137]

To paraphrase Mr Chow: "But did you die?" In this audiophile case: did you listen? Measured distortion is one part, listening is the other. You could, if you wanna, compare a hifi amplifier to a car engine. Pick 4 different engines with pretty similar torque & hp. They should perform more or less exactly like each other, right? Wrong. So many other parameters make up the result. They for sure perform different and sound different. I have a very nice hifi-system, I don't have a power conditioner, but I still do believe that they could be worth the sometimes high cost (Shunyata/Audioquest/IsoTek etc).

[@kilroyamer2352]

Bad analogy. Indeed 4 different engines with the same power specs may indeed produce 4 different results. The results is influenced by the engines designs, how it’s tuned, and its associated components such as transmission, climate control, etc. The closest analogy here is feeding the same engine with fuel from different stations. I would expect if my car has a well maintained fuel filtration system, I can expect the same performance with the same octane rating and well maintained service station (ie no water or crud in the fuel).

[@luisdemoraisecastrosimaole380]

And from a 12v, 100ah, lithium battery with a booster / regulator? can you make a coment? thanks in advance.

[@hugobloemers4425]

The audio emperor has no clothes, what a surprise ;)

[@johnshaw359]

I’ve found that improving the mains has improved the space/time aspect of my system, not so much better bass or treble tonality, after sorting out the mains noise using some motor run caps, bleed resistors and one of those mains sniffer devices along with 5kva isolation transformer I no longer feel the need to upgrade. I have deluded myself out of upgrading, that's a good thing.

[@mofarshchi]

Just this morning I was thinking that someone should run a test how a very dirty AC input would affect the audio signal. Thanks Amir jan

[@AudioScienceReview]

Great minds think alike! Thanks for watching it.

[@elvisburgerking8675]

I had a friend that was a HiFi nut, he considered switch mode power supplies to be the work of the devil and would often smash them with a hammer. he did the same thing to Televisions and managed to avoid ever owning or watching one. with HiFi he went to extreme lengths including building several pairs of concrete speakers , mounted on concrete pillars that went through the floor , not touching it, and were set in the ground, separate from the foundations for the walls. the turntable would also be mounted on a concrete pillar and layered stone/elastomer plinth also not touching the floor but going through it to concrete block in the ground. big enough to be able to experiment with up 18 inch long arms. and an airtight lid on it that must have weighed 20-25 Kg, . and you couldn't accidentally drop the lid either as it was hydraulically damped so closed quickly but very gently on its own. There was even scope for bettering the design, all you would need is to create a vacuum. and we did have a silent design thought out that didn't require a pump, it was never made but would have used very heavy lead weighted pistons in cylinders to create the vacuum. that's something HiFi nuts today can learn, i've never seen or heard of any sealed turntable designs ever since, and for obvious reasons makes a massive difference. He even built a home made Reel to Reel that took 15 inch reels and 4 tracks, 6 heads, made from 2 Revox machines mounted on a half inch thick aluminium plate, for recording live 3 hour concerts back in the late 1960s, 1970s and 1980s on to a single tape. before he started using Naks. He had a van to take it around to concerts. The tapes were not spliced either, he had a source of free 1 inch tape from an engineer at Ferranti who made mainframe computers, the tape would be cut into 2 reels of half inch tape, with beautiful aluminium handmade spools, using a winding machine fitted with a razor blade. we later tried something similar cutting high quality VHS and Betacam tape into smaller widths. he died happy of old age about 20 years ago, but anyway here is the point : he lived in a quarry well away from civilisation, without mains electricity, he had a huge rotatable aerial array on a tall mast on top of one hill and he had a wind generator on top of a second hill which constantly charged 2V deep cycle cells taken from fork lift trucks. a lot of them actually, as each bank had to supply + and - 90v DC from memory multitaped for every 2V, to make everything work. and he had 2 banks of these batteries, one bank would be getting charged while the other was in use, he would then swap the banks around each night. so all the HiFi equipment he had, and he had a lot of good stuff, was converted to pure DC operation, he would disconnect but leave the original power supplies inside the equipment and add extra sockets on the back for each DC voltage a particular piece of equipment required. cursing Japanese HiFi that needed upteen different voltages required to work. It would be a lot of effort for most people, but he didn't have much choice being so far away from the grid. and I'm telling you, everything sounded superb, even more so after dark. I would go there as often as I could, many others did so too, he had too many people wanting to be his friends. apart from music the only other sounds would be the birds, the wind and the rain, and the occasional sound of a cigarette lighter, otherwise it was eerily absolutely silent. and another thing, even when not listening to music, it was ultra peaceful not being surrounded by everyday electromagnetic fields. something you don't realise unless you've tried wilderness camping,. you can carry a guitar or even a saxophone, but would be hard to take you HiFi in a rucksack though.

[@homerjones3291]

Great video. Regenerators if nothing else give you a whole lot of outlets to plug your equipment in and give surge protection - did you do any tests on simple power strips that can connect 10 or so devices up to? Will the long black metal power strips that you can find at Home Depot or on Amazon do the trick?

[@AudioScienceReview]

Hard to know without testing them. They will only make an impact with higher power amplifiers though. For source devices, yes, any power strip should be good enough from fidelity point of view. Whether they are a safe design, that is another matter. I do plan on testing some UPS boxes.

[@patrickmeylemans9627]

Which amp do you use, speaking of power enough…

[@1Aquadon]

thanks Amir!!!

[@phildaintree2794]

What about dirty DC?.... high quality gear mostly has a nice linear PSU built in, but conventional wisdom is critical of cheap "wall-wart" switching PSUs. PCs using switching PSUs often criticised as streaming devices due to dirty DC.

[@ZombieLincoln666]

I have usb powered audio gear (a synthesizer and mixer) and the noise is a big issue. Easiest solution is just to use battery packs

[@BotraxDiaz]

I want to see tests on those shielded SATA cables. :)

[@daleromney6062]

Love this video. I have been telling people this for a long time, but it is nice to see you actually tested it and can show the normal DC conversion in audio devices cleans up the AC issues. I do use a conditioner, but for a different function. My power sometimes gets brown outs or huge surges (TX grid) and when the power exceeds about a 10 percent fluctuation my conditioner shuts off the power.

[@Thoughtflux]

Which conditioner are you using? I was thinking about a diy project using industrial grade filters like schaffner. Do you think it's a good idea?

[@daleromney6062]

@@Thoughtflux I use a Furman conditioner

[@whippetgas]

Cheers Amir, that was really interesting. I was just wondering if you noticed any increased buzzing or Humming physically coming from the D.U.T. when you applied the "Dimmer" AC? Asking because my understanding is that any dc component or ac offset bias causes inductors/transformers to operate inefficiently, and In my own experience I've noticed my isolation transformer audibly hums if I have a lot of high current loads on the same mains AC circuit. I guess SMPS is whole other kettle of fish but probably a lot less vulnerable considering their mode d'emploi ?

[@AudioScienceReview]

I did not but I do expect more substantial transformers groan and complain with such AC profile.

[@DalKangh]

Hi Amir. Interesting video. Forgive me if this a stupid question as I’m no engineer. Are you saying that no matter how dirty the AC is the DC is the same?

[@AudioScienceReview]

In a nutshell, yes.

[@victoraguirre2799]

Audio Science Review Hello. So my understanding is that noise in the lines and the quality of the electrical wiring in your house does not affect sound quality. But what about wireless devices, phones, Wifi routers, etc. Does all that radiation in the air penetrate your devices and degrade sound quality? I ask because I sometimes notice more sibilance in the sound and just over all a weaker sounding signal. Thank you!

[@RennieAsh]

Maybe if you put your phone right next to an unshielded low signal cable. I find I notice more silibance or harshness based on my mood. Just don't want to hear music occasionally

[@deemownskee]

@@RennieAsh Ok thanks. I noticed turning down the Wifi router transmit power helps. In assuming because the weaker the signal the less it interferes and you don’t always need it set to maximum. Something with wireless devices and routers degrades sound quality. Anyway thanks again

[@guyboisvert66]

You just have a bad component in the chain... When designing an audio component (and power supply), you know power won't be clean, there will be EMI, etc.

[@timt1406]

Very nice analysis. I have questions of a related nature. Is it possible to test power distortion effects on the life and degradation of power components…low quality capacitors vs high quality, etc.? If the answer is yes that could be a reason for power conditioning. I’m guessing most people interested in these topics have had to replace the power capacitors in their amps at some point. Also, I have a Dual turntable that has an AC/AC transformer and the speed control logic uses power frequency/Hz to derive 33RPM. is this a scenario for power conditioning? Thanks for your excellent videos.

[@alexsoo2390]

Great video.... Exactly what I have been hoping to see! Saves me thousands of dollars on not needing another box

[@AudioScienceReview]

I am glad you liked it.

[@garrardzero1]

This will probably also apply to Ethernet noise. An Ethernet connection has a 1 to 1 transformer for galvanic isolation, but does it also filter noise? And also if noise comes in via ethernet will this have a negative effect on the sound? I'm leaning towards probably not.

[@AudioScienceReview]

I have tested various Ethernet regenerators and as you suspect, they do absolutely nothing.

[@TheLkdude]

Wow, @Amir .. Still waters run deep! .. this could be the only documented history of this topic really proving the theory and practice! Thank you very much for the two fantastic videos!

[@dustinh845]

Doesn't some Schiit devices use straight AC? Or maybe I'm wrong.

[@AudioScienceReview]

That is only the external box that is an AC transformer. Internally that is used to generate positive and negative DC that is regulated so wouldn't get impacted either.

[@Iove-mm3dr]

You just saved me $6000.00 as I was going to buy a regenerator to replace my PowerPlant Premier. How about looking into power cable break-in? That's another audiophile holy grail...

[@nikosidis]

My amp goes to 11. It is 1 louder ;) Thanks for great info.

[@wightmanshawnk.3821]

LOL; love your videos! Audiophiles and their over-the-top systems get debunked again; seriously, AC distortion? Give me a break...

[@jaakanshorter]

I had a feeling about this 15 to 20 ago years. I have ran in to Some bad devices that made things not function correctly or didn't make a difference sound wise at all. I always thought if your ac power is ok you don't need some power device that cost as much as a cheap used car.

[@jabezhane]

I use all my audio mains filters and exotic power cables on my PC gear now (well it's sitting around may as well). Its odd. I work as a PC support guy and I get machines in that collapse all the time and I plug them into my 'clean' mains and they work fine. Customer takes them home...crashes and crashes. I then ask if they are plugged directly into the wall. They are. I tell them to get a simple APC surge/mains filter extension and bingo...crashes stop. Had that a few times.

[@markphilpot8734]

You can’t fight the truth. Too many snake oil peddlers selling crap that doesn’t work to neurotics who don’t know better. Oh well, so much for that. Clarity in a world full of hoo do is refreshing. Go Arin. Hope I spelt that correctly.

[@AudioScienceReview]

You didn't but it is fine. :) It is Amir.

[@markphilpot8734]

@@AudioScienceReview, thank you Amir for the correction. Would you please do a video on why some gear has a lower noise floor and have you seen or read anything about O Ring Transformers? They are supposed to be quieter than other types. The first piece I saw them in was a Denafrips DAC. The name is obvious from the look. More round than a toroidal core transformer. Enjoyed the AC distortion and noise video. Some designs are quieter than others. What does a piece of gear’s topology have to do with how it sounds? As I understand it, it refers to the bandwidth of the gear.

[@Andyuk911]

Fascinating - So as an example, a Mytek Brooklyn DAC using the AC mains inlet, will be far better than using the 12v input and a cheap SMPS, or indeed the same as spending an extra £400 on a linear 'Audio PS'.

[@pnaubry]

Happy to see back... the results are not surprising but it won’t stop the pseudo-science gurus and their disciples; nevertheless it is essential that scientific demonstrations like yours continue to be published... thank you Amir for all you do.

[@welderfixer]

Skip any chance of AC input problems and bypass the internal power supply with a battery bank.

[@peterlarkin762]

Ah sounds so simple doesn't it. Even battery packs need regulation and good charge/ protection circuitry.

[@DonutsReview]

When I turn on my Air Conditioner, my lamp light dims a little. Yet I hear no difference on my planar headphones. 😇

[@alcamacho1844]

Amir, a serious question. Your a measurement guru, I really like your talent and I am learning from you. Ok... if you had a power conditioner the size of a small shoe box and audio cables of all sorts, and they all measured strangely but truly transformed the music to a much higher positive level. Would you be surprised by the measuremment results? Question why this is possible? Surprised? Etc... (reason for my question, i have a new patent pending technology)

[@Thoughtflux]

Do you think power conditioners make a difference? I hear most audiophiles say it does but the measurements in this video doesn't support that claim. For some reason i think i hear interconnects of different metals sound different. I'm holding off my plans to buy a schaffner filter.. Do you think they work well for audio?

[@alcamacho1844]

@@Thoughtflux Mine makes a huge diffrence, currently searching for investors to launch.

[@Thoughtflux]

@@alcamacho1844 that's great! Are you trying to get your power conditioner patented?

[@alcamacho1844]

@@Thoughtflux Well, i got the technology and enjoy it to the fullest! Awesomeness, not only filtering but several other devices. However, to launch it its tricky, ill probably get allot if opposition. I need to get a partner with larger income sources, because I will have to UL list etc... Expensive matter to do it right.

[@Thoughtflux]

@@alcamacho1844 if you have measurements and approval of SQ by audiophiles.. Then your product has a chance. Not all good products become successful. Btw, have you checked out power conditioners from China? They are really good and really cheap! I'm evaluating a few Chinese products and will buy one in the near future.

[@Phos9]

So what I've never even seen attempted is an explanation as to why tiny distortions are a problem but the very high amplitude 60Hz signal is not.

[@Shoaibexpert]

Wow! Thanks for clarifying that and thanks for saving people tons of money. How do Linear PSUs compare to SMPSs in terms of distortion or sound quality?

[@prateeksamuel8603]

Hello Sir Amir. Hope your doing well. 😁😁😁😁😁👍👍👍👍👍

[@AudioScienceReview]

Hello and I am well thank you. Hope the same is true for you.

[@prateeksamuel8603]

@@AudioScienceReview haha life is like a sine wave just riding the wave 🤠🤠🤠🤠

[@prateeksamuel8603]

@@AudioScienceReview but yeah doing well. Thanks Sir!! 😊😊 Got me a few new vintage amps happy about that. 😁😁

[@jamieirwin6333]

Well done Amir, thanks for shedding some light on a shady practice.

[@mengshilim7364]

It is a problem if we don't have more voices/videos like Amir's.

[@edgar9651]

Thanks Amir! I am not surprised that they don't make a difference with devices like you tested which use only very little power. But how about power amplifiers? As far as I know the power supply part in power amps is expensive. In a very good power amp I wouldn't expect much of a difference. But with cheap power amps I guess clean AC power will make them better. Maybe you can test and show that one. Thanks!

[@rusedgin]

Like Amir pointed out, it's preferable to spend your money on a better equipment...

[@AudioScienceReview]

Power amplifiers are usually not hooked up to such gadgets as they reduce the available energy available to the amplifier. I did recently test the Equitech balanced power with an amplifier and showed that performance dropped a bit with it. See: www.audiosciencereview.com/forum/index.php?threads/equitech-1-5rq-balanced-power-review.24948/

[@homerjones3291]

It’s not recommended to plug amplifiers into these things, at least not into an outlet that does filtering. PS Audio regenerators usually have a bank of outlets where no filtering goes on. I plug my amp directly into the wall.

[@edgar9651]

@@AudioScienceReview Thanks Amir. PS Audio offers the PowerPlant 20 with 2000 VA output and I am pretty sure it's made for power amplifiers...

[@Boorock70]

Amir, blowing the snake oil products & myths ! Thanks.