Thank you, AmirM, for all these videos and the Audio Science Review -forum. I hope you understand how much all this means to us, who can appreciate all this information. Youre my hero. Thank your for your time.
Very interesting video on AC noise filtering Amir. Unless one is an experienced electronics engineer, it's difficult for most audiophiles to put these things into perspective. Some of these AC noise filtering, isolation transformers or regeneration products can cost an arm an a leg. You can spend way more money on some of these on a SOTA amplifier like a Benchmark AHB2. This video is a much needed warning.
Thanks for the informative video! I like this time format (which makes me watch more videos that in the end probably would sum up to more than a 20 min video that I would've considered too long to watch)
As for audio related topic, the main benefit of these EMI filters is to drastically reduce the COMMON MODE noise coming from our mains to our system, which in the end can poison our sensitive audio input. Adding some extra common mode filter is not detrimental and can be beneficial. Manufacturers may not be that kind to implement decently sized components. A 2 mH choke will give LX/2 or only 6.28 Ohm of impendence (resistance) at 1 KHz for common mode noise, at 100Hz it will be only 0.63Ohm. Usually the chokes of values ranging from 1 - 20 mH are used. They virtually should not create any resistance other than resistive to differential mode. These EMI filters at the PSU entry have a great role to do two things. 1. To reduce the noise generated by our device to the mains. What ever it is, the switching PSU, or all the rest, as a power consumer. 2. To reduse both the common mode and differential noise coming from mains to our device. Differential can be neglacted as it is easier to be reduced, but te most important is the reduction of common mode noise which can in the end poison the input of our amplifier and we get that hum noise in our speakers. Any current choke used for filtering can easily go into saturation at relatively low currents, it can be common mode current or a difference between neutral and live (difference in differential). That why is good to have a choke rated for higher current for reserve. Here the current for which they are usually rated can be 5 or 10A for example, but in reality a difference just in few milliamperes cam saturate the ferrite core.
Wow! The first video to actually answer the question! This shouldn't be a hard question, but instead of doing a simple A/ B comparision or tear down, everyone else defaults to describing highly questionable "experiences", giving long lists of things they bought, describing how those purchases made them feel, etc.
Same here BitterBuffalo! Suffice to say, Amir might be more into analytical sound while I look for a warmer tonality. True story: I often rely on Amir's reviews to go in the opposite direction, removing from my shopping lists items that "measure perfectly"!
@@AudioScienceReview Would be interesting with "Things to spend money on" and "What not to spend on". It's hard for consumers. Eg Hans Beekhuyzen on youtube is a HUGE promoter of better linear PSU for DACs. And to my understanding, you are of the opposite as we hear the sound and not power graphs. That said, he is no Electrical Engineer nor Developer, so I tend to trust ASR ´:)
Two truths that seem obvious but need to be said are 1.) never ask the person who is selling something whether you need it or not, and (not so related) 2.) don’t ask the person who you’re trying to sell something to how much they think that something’s worth.
I use AC filter because of 2 reasons: 1. to offer my gear best possible current so it can work as best as possible. 2. surge protection (reason alone good enough for me to have it). Adding AC filter won't impove sound as lots of naively expect and manufacturers falsely suggest, but it will help audio device to perform in a way it is designed to. Nothing more, wich is impossible and nothing less then products specifications. I also must emphase when we speak about internal noise how that noise is less variable (if at all) and more predictible than one that is in wall current wich one depends on gazzillion factors. Components inside audio devices have defined specs and behaviour, including noise and that can be much easier to deal with in terms of filtering. On the other hand, current comming out wall with noise is hugely variable during hour, day or week. I don't see any problem adding noise filter as long as those filters are in reasonable price level. The problem is that some companies sell those for thousands of $ or € and here I'm on your side.
I've said this many times on forums and BookFace groups: If you need an external line filter device to make your amp sound decent, YOU NEED A BETTER AMP! Great stuff as always, thank you so much for what you do, Amir!
@@AudioScienceReview Amirn, when you done the test on the trinnov altitude can you please throw it in the cat litter box for the scam that trinnov , dolby labs atmos is thank you.
@Jon Beck Hi Jon, I agree there are some usability issues with the layout (and it regularly does not display text properly on my trusted PC and slow reaction time of "tableau" when filtering) and subjective bias issues (have seen Amir will not recommend a product whose appearance he doesn't like, or which is costly but which performs acceptably). Unfortunately he puts a lot of trust in sine waves at 0dB but doesn't use extended listening tests with music. ASR is a useful additional review source but I wouldn't rely solely on it. Best, Rob
Yep, switching power supplies are noisier than most AC lines ever were. I worked in places with conditioned power for medical devices and other things. We used Isobars on the office computers not because the computers needed it, but to keep all the computer gear from back-feeding the AC line and messing with the conditioned outlets. Our station's transmitters were connected to copper waveguides that went straight to the tower-mounted antenna on top of a tall building that got struck by lightning often. We had to make it so lightning strikes didn't knock us off the air, or electrocute any people in the transmitter room. Not an impossible task, though more costly than the average homeowner is willing to spend.
What we can run into issues with is, if power conditioners/regenerators aren’t worth the money, many of us are still in meed of a quality power strip with multiple outlets - 8-10. So what’s a good solution for that?
This is a great video, as the other ones, but I feel maybe it is dumbed down a little too much (at least for my taste). Would have been great to have a little more details on the filters and what are they composed of, their effects... Maybe a future video? Please please please keep up doing what you do
I was thinking about getting this amp to add amos channels to my avr-X3700h, but after reading your review I won't be, what affordable two channel speaker amp would you recommend?
Thank you, this is one of the things I've argued with people on you tube about when telling them how stupid a multi hundred dollar power cord is and how the power at the end of a 1000 dollar cord is the same as the molded cord that comes with most products. They just look fancy. Most are so stiff they couldn't do any good for the power jack.
Can you make a video about distortion measures of speakers? These are never published because the numbers are in excess of 10%. How would this measurement be conducted?
Hi thank you very much for the very valuable video. I have to describe my experience. I have a cheap amp from Auna using a smps. I have noticed that on Sundays it sounds quite better (i.e. cleaner and more powerful). I live in an industrial district. And on Sunday the factories are almost all closed. Therefore i have concluded that smps are not that good at filtering noise coming from the external power distribution city grid. Speaking of linear psu instead i have the impression that EI transformers are much better than toroids at suppressing mains noise. But i have no instrument to check unfortunately. Thanks again and kind regards, gino
If your utility company will provide one, or get one yourself, monitor your mains voltage levels. Your industrial area weekday problems might be low voltage not extra noise.
@@glenncurry3041 Hi yes it could be that indeed. Lower voltage. I have seen around some distribution bar with digital display of the mains voltage. That could be very handy. Still i think that noise can play an important role. There are a lot of AC generator for audio purpose that promise to provide a very clean sine wave AC but they are usually very expensive, the good ones. Thanks again. Kind regards, gino
Safety compliant, or noise pollution compliant is not same as being audio compliant. It can conform to standards but still leak a lot of common mode noise into your device, where even with the Comon Mode Rejection and all the filtering can be insufficient to reduse it to desired levels. Take as an example a MacBook which has a well designed PSU but not connected to electrical ground the common mode noise can be higher than 20V, I can even feel it with the reverse side of my palm, or you can use an electrical live wire detector.
Unfortunately not all the things are well designed, I have found many flaws in the PS of the Topping A90 amplifier. The answer is not that simple, these filters protect your device from common mode noise, differential is way easier to filter.
@Jon Beck It's discernable by the tell-tale 60hz hum you'll get. Most audio equipment ("prosumer" or better, and maybe below) have a grounding screw on the back, You wire each together so that they are all at a common ground.
I have a problem with the air conditioner, when it´s working my studio monitors make a constant high pitch electrical noise, would a filter (like an EMI filter) help me with that?
There are some that are series surge protectors. These can cause current limiting. So if you have powerful amplifiers, you may not want to plug them into these. Otherwise, I can't think of a scenario that causes degradation in normal operational mode.
Do you believe in high quality ‘audio grade’ parts for example resistors, capacitors that measures the same but other materials were used to build them. Do you think this will influence the sound ? For example tonality..
Most domestic AC lines are not horrible. They are not wonderful but they are not disasters either, so in general some kind of line filtering isn't going to have a positive audible impact. But- there are probably some scenarios where a line filter would be useful. Running off a small portable generator maybe, or sharing a power line with a welding shop. But for most domestic audio gear I've ever bought, if the manufacturer didn't put enough into the design of the power supply to keep line noise out of the audio, I would return the thing and ask for my money back.
I would love to see tests on these "Power re generators" which some folks claim "dramatically" improve the sound of their systems. They seem to be very profitable "snake oil" .
Probably, AC filtering not required for precision audio devices, like modern DAC, power/pre amps with perfect filtering. But, on studio and live musicians using vintage style guitar/bass tube amps with really sensitive to AC noise due to its high gain. However, I do not know of examples of really good power filters or regenerators that can produce a perfect sine wave. It's easy to detect and reproduce AC noise in guitar tube amps - just toggle main power switch on amp, capacitors have enough power to keep the amplifier running for a couple of seconds, and listen/measure noise floor.
I recently added adam hall “power conditioner” that basically have some filters (not really a conditioner - just the name of the product) and I’ve noticed a change in sound. More bass, more details etc. So my equipment have internal filters also. Maybe the filters inside are not sufficient?
No. Nothing protects against a real lightning strike. It has so much energy that it will bust through these as if they do nothing. Best protection against that is an insurance policy for your home. And to some extent, a surge protector installed in your meter or at your service entrance. For the former, ask the power company. They are pretty cheap to put in (I have one and cost $320).
@@AudioScienceReview Great, I have already a HPFI protection. I imagine that the best protection is to pull out all your plugs when lightning is going on. :-)
How about a huge cordial core transformer and DC overlay on mains generated by all the switching power supplies? I've got a Harman Kardon 2.1 which is humming because of it. Do you have experiences with DC blockers?
Toroidal transformers are not the magic solution that they are sometimes said to be, at least not the ones that are installed in most consumer audio devices. To be proper, a toroidal transformer needs a very narrow core slot to prevent core saturation. This is expensive and somewhat difficult to do, and adds to the price, so (to my knowledge) it is almost never done. Unslotted toroidal transformer cores will saturate easily with small amounts of DC offset of the AC wave, and buzz like crazy. It's just the nature of the thing.
How does this Amazon amp prevent the Hf noise from the SMPS from “disturbing” the components inside the box? The filtering only prevents them from disturbing the AC line outside the box. They should at least shield the SMPS from the rest of the components in the box.
Internally, it is pretty easy to mitigate smps noise, because the switch mode frequency (and harmonics) are well known and clearly defined. Various methods can be used to get the switch mode noise down to a level that it cannot be heard at the speakers, such as using differential amplifiers (and exploiting common mode rejection) and notch filters. It varies from device to device, but there are many ways to do this. To be clear, the switch mode noise content only has to be reduced so that it is below -120dB or so.
@@tomterrific9459 I did not say it is not possible to shield the SMPS from the rest of the components, I just saw from the pictures that in this case the Amazon amp’s SMPS does not seem to be shielded from the other components. The most obvious method to mitigate the noise (but not the only method) is to put a box around the SMPS.
Great video !! , Question : We all know that there is different quality levels of Audio components , A $10000 MacIntosh isn't a $70 a basic Fosi Audio TB10A Stereo Audio Amplifier for example. So external noise and surge filtering devices also have different quality levels and it possible / worth to add a High End filter instead of a basic filter build in ??
Just no. The power supply in your audio gear runs on DC and that mandates filtering that is far more effective than anything done in mains. Mains filtering is almost always at high frequencies that you can't hear and at any rate, is trivial to filter inside the machine. And much cheaper too because internal voltages are much lower than mains.
I've seen CD player mods in the past where they remove the AC filters. I think the claim was that noise can end up stuck in a loop between the filter and the power transformer primary winding? Any merit to this theory? People claim this can reduce dynamics...but I've never seen it measured.
@Douglas Blake lol......as you know, there are a lot of "theories". Many of these theories are formed by people without a real understanding of how electricity/electronics even works, and consequently some pretty outlandish claims are made. There is typically a lot of "expectation bias" involved in most of these claims.
Thanks for your responses guys. I think the idea came from the famous Marantz CD63/67 mod thread on DIYAudio. The person in question had a write up of it on his website along with articles about how to optimise basic voltage regulators etc. I think he was an electrical engineer? See if I can find it...
@Douglas Blake haha I too am an engineer...a mechanical one though. Audio electronics are my hobby. I always follow the science though; hence being an ASR fan!
Hmm, I managed an auditorium PA for over 30 years and did the maintenance and some basic repair myself, though I did outsource more major repairs. Obviously I have heard and read a lot of arguments on various topics and investigated a few controversies for myself along the way. I never did anything truly audiophile out there but I did for example play around with speaker cable gauge and have come around to the opinion that the answer to whether things make an audible difference or not is often " well it depends". I do have a technical/sciences based education and interests. Among this I happen to know the theory of errors for systems. This is a statistical approach to defining and analyzing errors and it yields some interesting perspectives on the diverse opinions re often come across. Errors can be expressed as 95% of results are within +- a measurable tolerance. each system step can be expressed in this way. The total system error is the square root of the sum of each step squared. Total Error = (S1^2 + S2^2 + S3^2 + ....... + Sn^2 )^0.5. If we look at fixing errors in systems where the errors are spread differently, we get different results in terms of the effectiveness of our actions. Let's say each case is a 10 step system. Case 1: most steps have small errors with tolerance, a few are slightly higher but only one is a much larger error. The only action that makes any substantial difference is fixing the largest error. This leads to the conclusion that the only difference you perceive is when you attend to the largest error. I have certainly hear this comment in audio. Case 2: Most steps have a large error of about the same size, the rest are small, within tolerance. Attending to any 1 of the larger errors, even the largest one has little effect on the system overall. As we attend to the 2nd and 3rd errors we get slightly more improvement but still not much at all. It is only when the last remaining major error is dealt with that the whole system improves substantially. Now this is interesting because we made some real and substantial improvements to several steps that were majorly failing but experienced no real system improvements. Perhaps, this is like swapping out speaker cables and saying that doesn't matter. Well, I have to say that eventually after trying this for myself, my experience is that it can very much matter but to put it into perspective I didn't go ridiculously over the top with this, but enough to satisfy myself that the usual cable gauge charts appear to be woefully inadequate. What I did do though was go for a cable that was 2% of load impedance. Thinking that through some more, I suspect that a better approach may be to base the cable impedance of the amps output impedance so that a high damping factor amp retains good precision over the speakers. (assuming other amp properties are also good of course). However if the signal is getting messed up before the amp, it's still not going to make much difference. In my particular case, it was the must major thing the turned the PA from average to true sound reinforcement clarity and tonality. So on this particular topic on filtering, I see comments that it makes a very noticeable improvement and others like this. Personally I have not ever used anything other than simple surge protection either in PA or HiFi, so I'll sit on the fence but I do know that observed results in any system are very dependent on the spread of errors in the specific system. So, I tend to be of the opinion that maybe it depends on other factors. It's like, in the perfect theory, ground reference is the same everywhere. In practice though, the earth system is a network & not a ground plane. In the network, there are impedance anomalies and differences in potentials and current and spikes bouncing around. The ground plane theory just isn't reality which is one reason for balanced cables and ground lift. We don't want all the RFI EMI infecting signal reference etc. If someone says they put in a power regeneration and it makes a big difference for their $4000 audio system, I'm going to give then the benefit of the doubt on that. Like my engineer dad said, the theory only gives you a the initial system from which the applied science of engineering begins to optimize that system. That's the difference between a technician and an engineer.
Can you make a video analyzing exorbitant pricing of devices like dCS Bartok etc. costing more than $15,000? I.e. where those 1000s of dollars come from?
@@notthatperson8179 ASR Spectrum measurements at the DAC output show there is no difference between expensive DAC like dCS and cheap one like Allo Boss2
jovan jelic Demo a bartok for a couple of weeks then switch to one of these other dacs. The bartok is a bit of a good value to me. It includes a streamer and a headphone amp for $17k. They’re all built in the UK which has a high labor cost. They’re only sold by small specialist shops that provide service as part of the price. The cost to run a hifi shop is very high and even with the generous margins on dCS I doubt anybody is getting rich in the process.
@@notthatperson8179 On the contrary, profits are huge. Everybody wants as much cake as possible. For that reason, some vendors like Antipodes switched to direct sales. Bartok was $14k thing. As in the old saying, there is no impression like the first impression. Plenty of profit. But then the greed took over. Many vendors got greedy like that. For example, speakers with a hefty profit, Wilson Sophia 3, were selling for $16k to the delight of the owner, late Dave. But then overnight it jumped in price to $22k. Nothing materially changed on that day. Except greed took over. And what propelled the greed was the fact that stock market went straight up from March 2009 till now. I, couch potato investor, bought Microsoft at $26.50 and Apple at $20. I earned around $80k on those two stocks. If I were younger I would have probably bought Vivaldi or Rossini. But I know the black day is coming. There is no way I'm gonna plunge 1000s on something that gets obsolete in matter of days. What I would like to see is side by side measurements of Bartok vs Denafrips in both frequency and time domain and only then see if the difference in price is justified. Unfortunately, ASR only measures in frequency domain and basically that is measurement of averages.
jovan jelic I started with Conrad Johnson DAC then Naim V-1 followed by Chord Hugo finally a Berkeley Alpha. I wasn’t really in the market for a new dac just a streamer. My neighbor is a dCS dealer and he let me demo the bartok for a week after I demoed an Aurender server. It was just so much better than anything else I’d ever listened to that I bought one. In fact I told him I wasn’t returning the demo unit until I received mine. I’m not really an audiophile I just like listening to music.
Its not "exactly what youre going to find" on other surge protectors. It MIGHT be what you find, it might be better or worse. An audiophile grade filter (Furutech, for example) may be designed in such a way to further refine things for audio applications above and beyond what the FCC requires, or what you may or may not already have in your system.
Great content Amir, As a related topic, I would really like to know how much of an effect (if any) the "perfectness" of the incoming AC voltage waveform has on the audio produced by an amplifier. I don't know if this has ever been covered at ASR, but I would be interested to see this tested, ie, % thd+noise produced by an amplifier being fed less than perfect AC power vs % thd+noise produced by an amplifier being fed minimally distorted AC power.
@@AudioScienceReview Very good Amir, I would love to see the results of that. As you know, there are people that go to great lengths and expense to ensure that the AC voltage waveform coming into their amplifiers is as "perfect" as it can be, without any real evidence that small distortions on the AC voltage waveform can cause audible distortion problems on the audio output of the amplifier.
OK, but you forgot to answer the the real problematic parts. Those filters are there to "defend" the mains getting noisy because of high freq. switching. They must to do that because of FFC (US) and CE (EU) regulations, no choice, it's a rule. The PS would pollute the mains anyway, and your neighbours couldn't watch TV when you switch on the amplifier. What, if your power-amplifier has conventional PS, a big toroidal transformator with big buffer capacitors and rectifiers, and then maybe some DC voltage regulators. No high frequencies to get rid of. And then you can buy some Audiophile Grade HiFi powerstrips for $1000 and similar Hifi AC power cords, (that is almost free for $200). They look fancy and cool indeed, high quality no doubt. They are recommended because allegedly they can filter out every evil noises (the strip contains surge protection, overcurrent protection and filters) from the mains, the cable is shielded with braid copper like a network FTP cable. And it's made from AWG10 wire, just like your home welding apparatus' power cord. They say it's better if thicker. This was the real snake oil question to answer. Audiophile professionals make listening seances and they state that Audiophile Power Strip and Cord is much much better, you'll get defenitely more bass, airy mid and wide soundstage, less high frequency distortions. And this is a fact, they say so.
@@Obinjess I wouldn't be one to knock him. But I would have to agree most people dont want to spend crap on audio, we[americans] live in a country where every is virtually taken from us and it's a constant uphill battle. At least he has the luxury to buy something which helps him make money on the side while trying to grow a community most people are really unaware of or partake in with todays bluetooth this and that. A lot of the equipment he has is sent in for review, it does not belong to him. I take no sides, but I appreciate what he does even though measurements dont really give you the big picture. At least someone is trying and like Audioholics, which is where I come from and I dont want to say too much on that topic at least try to stop people from wasting money and provide some type of direction. But I am pretty sure this unit is Pyle producing for amazon with some extra investment cause pyle is a pyle of crap or they just decided to use the same case XD
I would rather a conditioner blow first not my equipment and more filtering may be needed depending on the amount of dirty current in your space and some of us have thousands of dollars invested and I for one want the extra security and I have very good conditioning that does not limit my playback
"more filtering may be needed depending on the amount of dirty current in your space" Do you know of any measurements that confirm that "dirty current" causes amplifiers to actually produce compromised audio?
You would be relying on luck in that situation. The surge protection devices are voltage rated. The one with the lower voltage will clamp before the higher voltage one. So for all you know, the one inside the amp may clamp first leaving the external one useless.
@@tomterrific9459 It's very simple. Take a portable player with build in speakers and listen on power from batery and next plug in a charger. Difference is pretty obvious. U may use a smartphone and blutooth speaker, but dont forget plug in charger to phone also. If it possible use a cable conection beetwen devices not a blutooth, cause wireless is also a partial filter of the noise. Sound powered from batery is less nervous and more smooth and clean.
Power quality varies widely and expecting any device to protect itself from this is pretty much a crap shoot. The consumer is fed all manner of marketing hype and lies about this. A real review about what is coming in to your house would at least give the audience some perspective. You will give it an honest perception as few others will!
Sir, you have extolled your hearing and the precision with which you can distinguish attributes of sound. You would have been a true PIA to ever sell 'Manager's Specials' to. It does cause me to want to remark about all the rest of us. Nearly everybody can run a mile with a bit of training. But only a few will run it in less than four minutes. Those folks deserve the BEST of equipment, coaches, etc. to better themselves. While the rest would perhaps get SOME benefit with intensive investments, the degree of the return on effort would be less and for most MUCH less, than for the small band of swifties or Golden Heels. plebeians
@@tomterrific9459 It is unlikely that we all require the absolute bestest ever stuff. You are biologically and therefore inherently unqualified to appreciate it. Your 'betters' may. I know I'm not in that class. Therefore I pay for what I CAN use. It's my recommendation for anyone.
I am easy to sell to actually. When they push that I buy this and that cable, I tell them if they drop the price and include them for free, I would. Two thirds of the time they do! That is how I own a bunch of high-end transparent cables and such. :) Sales people are incentivized to sell these high margin products so they happily drop the price on the main unit to make more commissions. I have even done this when buying mattresses. Negotiated a price and then the guy wanted to sell me insurance. After telling me that was the best price they could give me on the mattress, the salesman happily took the price down enough to include the extended warranty!
@Douglas Blake One of the weirdest physiological facts about ears, we can hear (well, SOME) the thermal noise of the ambient air. This article isn't killer technical but explains why, once you wrap your head around it, the entire audio industry is a mess. It's because hearing is so very much individualized and therefore independently subjective. Every consumer presents an unique challenge. We are not buying dish washers.
My challenge to anyone on ASR, is to show me that you understand what the following means… ”man has such a predilection for systems and abstract deductions that he is ready to distort the truth intentionally, he is ready to ignore the evidence of his senses only to justify his logic.” Dostoevsky
Once again you are absolutely right but you don't paint all the picture. You should tell the people that as with anything in life comes with a price. You didn't buy a 100k system just because you have the money to blow. Tell us how it is better than the average 1000 or 10 000 system. What are the measurements that makes the difference ? Because it sounds too much like a 100$ dac is all someone need. Same thing with audioholics : the guy preach cables are no important but uses Kimber kables. As a principal he should use zip cords. (In a proper gage ;) The ones that preach the most on measurements have the best gears in general and the people with entry level systems believes that what you guys are talking about apply to them. I would like to have a real correlation between the sound we are experiencing and the quality of the gear.
@Douglas Blake Well.. Are you saying that Amir's 100K system is to found a cottage industry ? He put non of his wisdom into his buying process ? It is all an eye candy ? This fight between the "ears believer" and the "mesurements proselytes" is twisting reality so much that people are starting their own reality. Snake oil aside between two product well engineered the one who cost more generally/always offers more. Specially on a scale of 1 to 10. You just have to see the equipement the man is using for mesuments. It doesn't come cheap. I'm not saying that a 1k system can't be amazing for the price but common man you gotta know deep inside that's not the top. I'm not an elitist at all but real quality never comes cheap.
@Douglas Blake No worth for you but let's not play with absolut. It is worth something for another guy and please let's not shame that person because of his preference and taste. The same could be say with wine, cars, house, food,... When you go to a fine restaurant you pay for the experience. And building a system doesn't come cheap. I've done it too countless times. You have to invest in equipements that cost a lot of money to be able to design something at least good technically. It may cost 1K in parts but the labor, the experience, the craftmanship,.. all that is impossible to assess. So saying to newbies well with a 1k system you can beat a 10k system in the market should come with an BIG *. I don't have ill intent. I just don't like when people uses specific examples and build rules with it like it's the absolut truth. This is what fuel unnecessary arguments, the lack of nuances and no context.
@Douglas Blake and man i'm a DIY guy myself but i don't pretend that my creations can compete with the creations of real experts, real engineers specialize in the domain doing real research and pushing bounderies. That's another problem with audio. The lack of figures of authority. Everybody thinking they know everything because they have assemble a kit or succed in building a simple single ended amp or a pushpull or a class a/ ab. It's like building a computer from parts and then thinking you are an IT engineer. You sure sound like a clever guy and you may have cracked 90% of the system but the last 10% are doing real work and bringing a value that enthousiast people value and pay for it. The first one being Amir !
@Douglas Blake And i totally agree with you. Really all the way ! Higher prices doesn't mean nothing by it's own. There are a lot of overprice stuff in the market. But we should never generalize to the point of thinking it's the rule. Appreciation start first with preference which is subjective. Specially in audio some like class A, other tubes, other this and that....But performance is quantifiable and can be mesured. Wether it is appreciated or not is irrelevant when it comes to it in my opinion. The best build, higher quality materials, low level of distortions, linearity, all the thing we can mesures and that prooves that the product is developped to the highest standard brings directly value regardless of what we personnally think about the product. And those things cost a lot of money. I've listend to the Crown amp you are talking about. It is amazing and powerfull but personnaly i don't like the sound it produces. a small A/B amp like the Atoll IN30 suits better my taste. Or a Hegel H95 or even a small amp like a taga harmony hta 700b with electro harmonix tubes and better caps in the input signal and coupling. This is my personal preferences but the argument could be made by saying are they better developped ? No ! But we are comparing Apple and Oranges here. To be more specific we should compare all the crown amps and see if there is no benefits going from their entry level amp to the top level. That is all i'm saying, context is very important.
I do not know for more than 500 USD, but for most audio equipment under 500 the PSU is not that well designed, many will not have any filtering at all. most switching PSU do not have any output filtering other than capacitive.
Not one single mention of how this noise can be easily picked up by those of us who have other hobbies such as ham radio. Sorry Amir but not all of us are just audiophiles. We have other hobbies too which need clean power and no RF interference.
The required filtering on the AC line of all devices should keep the noise inside the case. Do you find adding supplemental filtering further lowers the noise being pushed out the AC line?
@@tomterrific9459 yes. Some switch mode power supplies are so electrically noisy that they turn power cords into transmission lines for RFI. This is one of the reasons why some audiophiles turn to upgraded linear power supplies which are not as noisy in the RF band. If you would like more information the ARRL has a great section on their site dealing with EMI and RFI mitigation. Companies like Palomar make filters designed to mitigate this interference. MFJ Enterprises makes RFI sniffers. The biggest culprits are the cheap switch mode power supplies and the poorly designed power supplies in cheap audio gear. You can hear them on ham radio gear and see the interference on a SDR spectrum sweep. I hope this was helpful to you.
If you got to $100K with these tweaks, you have my sympathy! If on the other hand if you spent it on speakers, proper amplification and such, not at all. My own system costs that much and you don't see me complaining about that. :)
Audio Science Review tests components for how they measure and do not offer subjective evaluation of the sound signature of components. This is not to say that a Krell sound the same as a Rowland which sounds the same as a Denon or Yamaha or Marantz. ASR is Julian Hirach revisited. The reviews are interesting and to be read alongside subjective reviews. Components may measure the same given the current state of our knowledge of measuring electronics but may sound different for reasons that cannot be accurately measured or repeated. ASR reviews are not to be taken as Gospel but as one facet of the component’s performance. Just like subject reviews cannot be taken as Gospel as they depend so much of the impressions of the reviewer (system, room, associated components). Let’s put it this way, at least you won’t spend money on Peter Belt type tweaks or maybe you spend your money of other areas like room treatment that might offer better ROI than these tweets.
@@navinadv Most ASR reviews do in fact include a subjective listening test towards the end of each review. For instance, in headphone amp reviews, a number of common headphones are tested listening to several recordings, often comparing the sound signature to other similar products.
You are funny. You buy cheap , basically junk measure it and tell us noise filters are useless. I have to laugh at some of your posts. Sadly some of the followers actually think you know what your doing.
I find it kind of funny that you think one cap across the AC line in is all you need for filtering the AC in. I guess you never listen to really detailed systems or have done any testing on detailed systems. Next you'll tell people they don't use any ac line filters in recording studios either. Come on, if you're going to do these kinds of videos tell some truth.
@@MrsZambezi no, but I do have proper REAL filters. Conditioner, haha, fancy word for these manufacturers to use so suckers who think they are audiophiles or have golden ears will buy them.
Thank you, AmirM, for all these videos and the Audio Science Review -forum. I hope you understand how much all this means to us, who can appreciate all this information. Youre my hero. Thank your for your time.
Very interesting video on AC noise filtering Amir. Unless one is an experienced electronics engineer, it's difficult for most audiophiles to put these things into perspective. Some of these AC noise filtering, isolation transformers or regeneration products can cost an arm an a leg. You can spend way more money on some of these on a SOTA amplifier like a Benchmark AHB2. This video is a much needed warning.
Thanks for the informative video! I like this time format (which makes me watch more videos that in the end probably would sum up to more than a 20 min video that I would've considered too long to watch)
As for audio related topic, the main benefit of these EMI filters is to drastically reduce the COMMON MODE noise coming from our mains to our system, which in the end can poison our sensitive audio input. Adding some extra common mode filter is not detrimental and can be beneficial. Manufacturers may not be that kind to implement decently sized components.
A 2 mH choke will give LX/2 or only 6.28 Ohm of impendence (resistance) at 1 KHz for common mode noise, at 100Hz it will be only 0.63Ohm. Usually the chokes of values ranging from 1 - 20 mH are used. They virtually should not create any resistance other than resistive to differential mode.
These EMI filters at the PSU entry have a great role to do two things.
1. To reduce the noise generated by our device to the mains. What ever it is, the switching PSU, or all the rest, as a power consumer.
2. To reduse both the common mode and differential noise coming from mains to our device. Differential can be neglacted as it is easier to be reduced, but te most important is the reduction of common mode noise which can in the end poison the input of our amplifier and we get that hum noise in our speakers.
Any current choke used for filtering can easily go into saturation at relatively low currents, it can be common mode current or a difference between neutral and live (difference in differential). That why is good to have a choke rated for higher current for reserve. Here the current for which they are usually rated can be 5 or 10A for example, but in reality a difference just in few milliamperes cam saturate the ferrite core.
Wow! The first video to actually answer the question! This shouldn't be a hard question, but instead of doing a simple A/ B comparision or tear down, everyone else defaults to describing highly questionable "experiences", giving long lists of things they bought, describing how those purchases made them feel, etc.
I am regularly delighted by how much I learn from your videos. Thank you for continuing to educate us.
Amir I think we got different taste in what we like out of audiosources, but this video is very helpful. thanks!
Same here BitterBuffalo! Suffice to say, Amir might be more into analytical sound while I look for a warmer tonality. True story: I often rely on Amir's reviews to go in the opposite direction, removing from my shopping lists items that "measure perfectly"!
Can you do a video about which are the most important things to spend on for a hifi system?
Could do. Thanks for the suggestion.
@@AudioScienceReview And please put in a joke about TOSLINK cables with gold plated terminals! :D
@@AudioScienceReview Would be interesting with "Things to spend money on" and "What not to spend on". It's hard for consumers. Eg Hans Beekhuyzen on youtube is a HUGE promoter of better linear PSU for DACs. And to my understanding, you are of the opposite as we hear the sound and not power graphs. That said, he is no Electrical Engineer nor Developer, so I tend to trust ASR ´:)
@@jungtarcph He’s also a big fan of incredibly expensive cabling.
Two truths that seem obvious but need to be said are 1.) never ask the person who is selling something whether you need it or not, and (not so related) 2.) don’t ask the person who you’re trying to sell something to how much they think that something’s worth.
I use AC filter because of 2 reasons:
1. to offer my gear best possible current so it can work as best as possible.
2. surge protection (reason alone good enough for me to have it).
Adding AC filter won't impove sound as lots of naively expect and manufacturers falsely suggest, but it will help audio device to perform in a way it is designed to. Nothing more, wich is impossible and nothing less then products specifications.
I also must emphase when we speak about internal noise how that noise is less variable (if at all) and more predictible than one that is in wall current wich one depends on gazzillion factors. Components inside audio devices have defined specs and behaviour, including noise and that can be much easier to deal with in terms of filtering.
On the other hand, current comming out wall with noise is hugely variable during hour, day or week.
I don't see any problem adding noise filter as long as those filters are in reasonable price level. The problem is that some companies sell those for thousands of $ or € and here I'm on your side.
I've said this many times on forums and BookFace groups: If you need an external line filter device to make your amp sound decent, YOU NEED A BETTER AMP!
Great stuff as always, thank you so much for what you do, Amir!
Much appreciated. Thanks for watching.
Can you make a video about hybrid power supplies and whether there are any advantages?
Long time reader at your forum, first time viewer. You look nothing like in your picture.
:) My disguise is blown!
Yeah... i thought Amir is Chinese...
@@AudioScienceReview Amirn, when you done the test on the trinnov altitude can you please throw it in the cat litter box for the scam that trinnov , dolby labs atmos is thank you.
@Jon Beck I look up measurement and discussion on products that are of interest to me. Also 'long time' is relative.
@Jon Beck Hi Jon, I agree there are some usability issues with the layout (and it regularly does not display text properly on my trusted PC and slow reaction time of "tableau" when filtering) and subjective bias issues (have seen Amir will not recommend a product whose appearance he doesn't like, or which is costly but which performs acceptably). Unfortunately he puts a lot of trust in sine waves at 0dB but doesn't use extended listening tests with music. ASR is a useful additional review source but I wouldn't rely solely on it. Best, Rob
Yep, switching power supplies are noisier than most AC lines ever were. I worked in places with conditioned power for medical devices and other things. We used Isobars on the office computers not because the computers needed it, but to keep all the computer gear from back-feeding the AC line and messing with the conditioned outlets. Our station's transmitters were connected to copper waveguides that went straight to the tower-mounted antenna on top of a tall building that got struck by lightning often. We had to make it so lightning strikes didn't knock us off the air, or electrocute any people in the transmitter room. Not an impossible task, though more costly than the average homeowner is willing to spend.
What we can run into issues with is, if power conditioners/regenerators aren’t worth the money, many of us are still in meed of a quality power strip with multiple outlets - 8-10. So what’s a good solution for that?
This is a great video, as the other ones, but I feel maybe it is dumbed down a little too much (at least for my taste). Would have been great to have a little more details on the filters and what are they composed of, their effects... Maybe a future video?
Please please please keep up doing what you do
I was thinking about getting this amp to add amos channels to my avr-X3700h, but after reading your review I won't be, what affordable two channel speaker amp would you recommend?
Thank you, this is one of the things I've argued with people on you tube about when telling them how stupid a multi hundred dollar power cord is and how the power at the end of a 1000 dollar cord is the same as the molded cord that comes with most products. They just look fancy. Most are so stiff they couldn't do any good for the power jack.
Nice video, very pragmatic...
Thank you!
Can you make a video about distortion measures of speakers? These are never published because the numbers are in excess of 10%. How would this measurement be conducted?
Actually modern speaker designs can have significantly less distortion, less than 1% in many cases.
Thanks
Hi thank you very much for the very valuable video. I have to describe my experience. I have a cheap amp from Auna using a smps. I have noticed that on Sundays it sounds quite better (i.e. cleaner and more powerful). I live in an industrial district. And on Sunday the factories are almost all closed. Therefore i have concluded that smps are not that good at filtering noise coming from the external power distribution city grid.
Speaking of linear psu instead i have the impression that EI transformers are much better than toroids at suppressing mains noise. But i have no instrument to check unfortunately. Thanks again and kind regards, gino
If your utility company will provide one, or get one yourself, monitor your mains voltage levels. Your industrial area weekday problems might be low voltage not extra noise.
@@glenncurry3041 Hi yes it could be that indeed. Lower voltage. I have seen around some distribution bar with digital display of the mains voltage. That could be very handy. Still i think that noise can play an important role. There are a lot of AC generator for audio purpose that promise to provide a very clean sine wave AC but they are usually very expensive, the good ones.
Thanks again. Kind regards, gino
Safety compliant, or noise pollution compliant is not same as being audio compliant. It can conform to standards but still leak a lot of common mode noise into your device, where even with the Comon Mode Rejection and all the filtering can be insufficient to reduse it to desired levels. Take as an example a MacBook which has a well designed PSU but not connected to electrical ground the common mode noise can be higher than 20V, I can even feel it with the reverse side of my palm, or you can use an electrical live wire detector.
Good video. I'm so fed up with people telling others that they need expensive power supply filters to protect their "investment".
Unfortunately not all the things are well designed, I have found many flaws in the PS of the Topping A90 amplifier. The answer is not that simple, these filters protect your device from common mode noise, differential is way easier to filter.
Great review as always, could you please suggest a AC noise filter for a tube amplifier, thanks
Most audio issues people blame on line noise is probably due to lack of ground-loop isolation.
@Jon Beck It's discernable by the tell-tale 60hz hum you'll get. Most audio equipment ("prosumer" or better, and maybe below) have a grounding screw on the back, You wire each together so that they are all at a common ground.
I have a problem with the air conditioner, when it´s working my studio monitors make a constant high pitch electrical noise, would a filter (like an EMI filter) help me with that?
Can a line filter negatively affect operation of a power amplifier?
There are some that are series surge protectors. These can cause current limiting. So if you have powerful amplifiers, you may not want to plug them into these. Otherwise, I can't think of a scenario that causes degradation in normal operational mode.
Do you believe in high quality ‘audio grade’ parts for example resistors, capacitors that measures the same but other materials were used to build them. Do you think this will influence the sound ? For example tonality..
Components will measure differently as temperature changes. Some components are more stable to temperature changes compared to others.
Yes they are different and they actually measure different, but you do not need to sale your kidney as the benefits are questionable sometimes.
Most domestic AC lines are not horrible. They are not wonderful but they are not disasters either, so in general some kind of line filtering isn't going to have a positive audible impact. But- there are probably some scenarios where a line filter would be useful. Running off a small portable generator maybe, or sharing a power line with a welding shop. But for most domestic audio gear I've ever bought, if the manufacturer didn't put enough into the design of the power supply to keep line noise out of the audio, I would return the thing and ask for my money back.
I would love to see tests on these "Power re generators" which some folks claim "dramatically" improve the sound of their systems. They seem to be very profitable "snake oil" .
Probably, AC filtering not required for precision audio devices, like modern DAC, power/pre amps with perfect filtering. But, on studio and live musicians using vintage style guitar/bass tube amps with really sensitive to AC noise due to its high gain. However, I do not know of examples of really good power filters or regenerators that can produce a perfect sine wave.
It's easy to detect and reproduce AC noise in guitar tube amps - just toggle main power switch on amp, capacitors have enough power to keep the amplifier running for a couple of seconds, and listen/measure noise floor.
I recently added adam hall “power conditioner” that basically have some filters (not really a conditioner - just the name of the product) and I’ve noticed a change in sound. More bass, more details etc. So my equipment have internal filters also. Maybe the filters inside are not sufficient?
Love your channel and have been subscribed for nearly a week now. :-)
May I please ask you if these products also have a lightning protection?
No. Nothing protects against a real lightning strike. It has so much energy that it will bust through these as if they do nothing. Best protection against that is an insurance policy for your home. And to some extent, a surge protector installed in your meter or at your service entrance. For the former, ask the power company. They are pretty cheap to put in (I have one and cost $320).
@@AudioScienceReview Great, I have already a HPFI protection.
I imagine that the best protection is to pull out all your plugs when lightning is going on. :-)
How about a huge cordial core transformer and DC overlay on mains generated by all the switching power supplies? I've got a Harman Kardon 2.1 which is humming because of it. Do you have experiences with DC blockers?
Mechanical buzzing/hum can indeed be annoying. Standard surge protectors don't do anything for them either.
Toroidal transformers are not the magic solution that they are sometimes said to be, at least not the ones that are installed in most consumer audio devices. To be proper, a toroidal transformer needs a very narrow core slot to prevent core saturation. This is expensive and somewhat difficult to do, and adds to the price, so (to my knowledge) it is almost never done. Unslotted toroidal transformer cores will saturate easily with small amounts of DC offset of the AC wave, and buzz like crazy. It's just the nature of the thing.
@Douglas Blakeits humming without signal or speaker attached. It is the transformer.
@Douglas Blake Unslotted toroidal transformers can hum like crazy if the AC is non-symmetrical.
How does this Amazon amp prevent the Hf noise from the SMPS from “disturbing” the components inside the box? The filtering only prevents them from disturbing the AC line outside the box. They should at least shield the SMPS from the rest of the components in the box.
It has good bit of physical distance to the amplifier board. But sure there may be some noise bleeding into the amp.
Internally, it is pretty easy to mitigate smps noise, because the switch mode frequency (and harmonics) are well known and clearly defined. Various methods can be used to get the switch mode noise down to a level that it cannot be heard at the speakers, such as using differential amplifiers (and exploiting common mode rejection) and notch filters. It varies from device to device, but there are many ways to do this. To be clear, the switch mode noise content only has to be reduced so that it is below -120dB or so.
@@tomterrific9459 I did not say it is not possible to shield the SMPS from the rest of the components, I just saw from the pictures that in this case the Amazon amp’s SMPS does not seem to be shielded from the other components. The most obvious method to mitigate the noise (but not the only method) is to put a box around the SMPS.
Amir, you’ve said Audio VIDEO Review site in last part of video)
Maybe I should go buy out that domain before it is too late!!! :)
Great video !! , Question : We all know that there is different quality levels of Audio components , A $10000 MacIntosh isn't a $70 a basic Fosi Audio TB10A Stereo Audio Amplifier for example. So external noise and surge filtering devices also have different quality levels and it possible / worth to add a High End filter instead of a basic filter build in ??
Just no. The power supply in your audio gear runs on DC and that mandates filtering that is far more effective than anything done in mains. Mains filtering is almost always at high frequencies that you can't hear and at any rate, is trivial to filter inside the machine. And much cheaper too because internal voltages are much lower than mains.
I've seen CD player mods in the past where they remove the AC filters. I think the claim was that noise can end up stuck in a loop between the filter and the power transformer primary winding? Any merit to this theory? People claim this can reduce dynamics...but I've never seen it measured.
@Douglas Blake lol......as you know, there are a lot of "theories". Many of these theories are formed by people without a real understanding of how electricity/electronics even works, and consequently some pretty outlandish claims are made. There is typically a lot of "expectation bias" involved in most of these claims.
@Douglas Blake Yes, I agree. That statement was probably originally made by somebody not experienced in electricity/electronics
Sounds like something from the GR Research forum...lol.
Thanks for your responses guys. I think the idea came from the famous Marantz CD63/67 mod thread on DIYAudio. The person in question had a write up of it on his website along with articles about how to optimise basic voltage regulators etc. I think he was an electrical engineer? See if I can find it...
@Douglas Blake haha I too am an engineer...a mechanical one though. Audio electronics are my hobby. I always follow the science though; hence being an ASR fan!
Can emi filter improve audio quality?
Amir, did you just establish new portal: "Audio Video Review"? @5:05 ;-)
Ah, you heard that? :) You can see the lazy side of me not to want to redo the video just for that.
@@AudioScienceReview About time you do some work on video as well?
@@grisgriz85 I wish I have the time. As you may know, my career and experience also span video.
And many devices have a traditional power supply which doesn't generate the noise that a switching supply does.
We must protect Amir at all costs! 🙏
Very informative. Thanks.
Hmm, I managed an auditorium PA for over 30 years and did the maintenance and some basic repair myself, though I did outsource more major repairs. Obviously I have heard and read a lot of arguments on various topics and investigated a few controversies for myself along the way. I never did anything truly audiophile out there but I did for example play around with speaker cable gauge and have come around to the opinion that the answer to whether things make an audible difference or not is often " well it depends". I do have a technical/sciences based education and interests. Among this I happen to know the theory of errors for systems. This is a statistical approach to defining and analyzing errors and it yields some interesting perspectives on the diverse opinions re often come across. Errors can be expressed as 95% of results are within +- a measurable tolerance. each system step can be expressed in this way. The total system error is the square root of the sum of each step squared. Total Error = (S1^2 + S2^2 + S3^2 + ....... + Sn^2 )^0.5.
If we look at fixing errors in systems where the errors are spread differently, we get different results in terms of the effectiveness of our actions. Let's say each case is a 10 step system.
Case 1: most steps have small errors with tolerance, a few are slightly higher but only one is a much larger error.
The only action that makes any substantial difference is fixing the largest error.
This leads to the conclusion that the only difference you perceive is when you attend to the largest error.
I have certainly hear this comment in audio.
Case 2: Most steps have a large error of about the same size, the rest are small, within tolerance.
Attending to any 1 of the larger errors, even the largest one has little effect on the system overall.
As we attend to the 2nd and 3rd errors we get slightly more improvement but still not much at all.
It is only when the last remaining major error is dealt with that the whole system improves substantially.
Now this is interesting because we made some real and substantial improvements to several steps that were majorly failing but experienced no real system improvements. Perhaps, this is like swapping out speaker cables and saying that doesn't matter. Well, I have to say that eventually after trying this for myself, my experience is that it can very much matter but to put it into perspective I didn't go ridiculously over the top with this, but enough to satisfy myself that the usual cable gauge charts appear to be woefully inadequate. What I did do though was go for a cable that was 2% of load impedance. Thinking that through some more, I suspect that a better approach may be to base the cable impedance of the amps output impedance so that a high damping factor amp retains good precision over the speakers. (assuming other amp properties are also good of course). However if the signal is getting messed up before the amp, it's still not going to make much difference. In my particular case, it was the must major thing the turned the PA from average to true sound reinforcement clarity and tonality.
So on this particular topic on filtering, I see comments that it makes a very noticeable improvement and others like this. Personally I have not ever used anything other than simple surge protection either in PA or HiFi, so I'll sit on the fence but I do know that observed results in any system are very dependent on the spread of errors in the specific system. So, I tend to be of the opinion that maybe it depends on other factors. It's like, in the perfect theory, ground reference is the same everywhere. In practice though, the earth system is a network & not a ground plane. In the network, there are impedance anomalies and differences in potentials and current and spikes bouncing around. The ground plane theory just isn't reality which is one reason for balanced cables and ground lift. We don't want all the RFI EMI infecting signal reference etc.
If someone says they put in a power regeneration and it makes a big difference for their $4000 audio system, I'm going to give then the benefit of the doubt on that. Like my engineer dad said, the theory only gives you a the initial system from which the applied science of engineering begins to optimize that system. That's the difference between a technician and an engineer.
Can you make a video analyzing exorbitant pricing of devices like dCS Bartok etc. costing more than $15,000? I.e. where those 1000s of dollars come from?
I have a bartok and it’s the best money I ever spent. 40% goes to retailer.
@@notthatperson8179 ASR Spectrum measurements at the DAC output show there is no difference between expensive DAC like dCS and cheap one like Allo Boss2
jovan jelic Demo a bartok for a couple of weeks then switch to one of these other dacs. The bartok is a bit of a good value to me. It includes a streamer and a headphone amp for $17k. They’re all built in the UK which has a high labor cost. They’re only sold by small specialist shops that provide service as part of the price. The cost to run a hifi shop is very high and even with the generous margins on dCS I doubt anybody is getting rich in the process.
@@notthatperson8179 On the contrary, profits are huge. Everybody wants as much cake as possible. For that reason, some vendors like Antipodes switched to direct sales. Bartok was $14k thing. As in the old saying, there is no impression like the first impression. Plenty of profit. But then the greed took over. Many vendors got greedy like that. For example, speakers with a hefty profit, Wilson Sophia 3, were selling for $16k to the delight of the owner, late Dave. But then overnight it jumped in price to $22k. Nothing materially changed on that day. Except greed took over. And what propelled the greed was the fact that stock market went straight up from March 2009 till now. I, couch potato investor, bought Microsoft at $26.50 and Apple at $20. I earned around $80k on those two stocks. If I were younger I would have probably bought Vivaldi or Rossini. But I know the black day is coming. There is no way I'm gonna plunge 1000s on something that gets obsolete in matter of days. What I would like to see is side by side measurements of Bartok vs Denafrips in both frequency and time domain and only then see if the difference in price is justified. Unfortunately, ASR only measures in frequency domain and basically that is measurement of averages.
jovan jelic I started with Conrad Johnson DAC then Naim V-1 followed by Chord Hugo finally a Berkeley Alpha. I wasn’t really in the market for a new dac just a streamer. My neighbor is a dCS dealer and he let me demo the bartok for a week after I demoed an Aurender server. It was just so much better than anything else I’d ever listened to that I bought one. In fact I told him I wasn’t returning the demo unit until I received mine. I’m not really an audiophile I just like listening to music.
Its not "exactly what youre going to find" on other surge protectors. It MIGHT be what you find, it might be better or worse. An audiophile grade filter (Furutech, for example) may be designed in such a way to further refine things for audio applications above and beyond what the FCC requires, or what you may or may not already have in your system.
Oh lawd... ALL amplifiers have input filtering. This discussion is unwarranted.
Great content Amir,
As a related topic, I would really like to know how much of an effect (if any) the "perfectness" of the incoming AC voltage waveform has on the audio produced by an amplifier. I don't know if this has ever been covered at ASR, but I would be interested to see this tested, ie, % thd+noise produced by an amplifier being fed less than perfect AC power vs % thd+noise produced by an amplifier being fed minimally distorted AC power.
@Douglas Blake Hi Douglas,
Yes, I completely agree with you 100%.
I would just like to see some measurements sometime that would confirm this.
Lee
I plan to do some testing and videos on lab generated clean AC so stay tuned! I will also do the reverse by distorting the power even more.
@@AudioScienceReview Thanks Amir. That would be great.
@Douglas Blake Yes, that would be a very good way to measure the AC riding on the rails.
@@AudioScienceReview Very good Amir, I would love to see the results of that. As you know, there are people that go to great lengths and expense to ensure that the AC voltage waveform coming into their amplifiers is as "perfect" as it can be, without any real evidence that small distortions on the AC voltage waveform can cause audible distortion problems on the audio output of the amplifier.
Absolutely right!
This goes against my experience. Have you ever considered that the AC filtering within components may not (and almost certainly isnt) be perfect??
OK, but you forgot to answer the the real problematic parts. Those filters are there to "defend" the mains getting noisy because of high freq. switching. They must to do that because of FFC (US) and CE (EU) regulations, no choice, it's a rule. The PS would pollute the mains anyway, and your neighbours couldn't watch TV when you switch on the amplifier.
What, if your power-amplifier has conventional PS, a big toroidal transformator with big buffer capacitors and rectifiers, and then maybe some DC voltage regulators. No high frequencies to get rid of. And then you can buy some Audiophile Grade HiFi powerstrips for $1000 and similar Hifi AC power cords, (that is almost free for $200). They look fancy and cool indeed, high quality no doubt. They are recommended because allegedly they can filter out every evil noises (the strip contains surge protection, overcurrent protection and filters) from the mains, the cable is shielded with braid copper like a network FTP cable. And it's made from AWG10 wire, just like your home welding apparatus' power cord. They say it's better if thicker.
This was the real snake oil question to answer. Audiophile professionals make listening seances and they state that Audiophile Power Strip and Cord is much much better, you'll get defenitely more bass, airy mid and wide soundstage, less high frequency distortions. And this is a fact, they say so.
isn't that unit a pyle? looks exactly like a pyle unit lol
He spent all his money on test gear so he can't afford good equipment to test.
@@Obinjess I wouldn't be one to knock him. But I would have to agree most people dont want to spend crap on audio, we[americans] live in a country where every is virtually taken from us and it's a constant uphill battle. At least he has the luxury to buy something which helps him make money on the side while trying to grow a community most people are really unaware of or partake in with todays bluetooth this and that.
A lot of the equipment he has is sent in for review, it does not belong to him.
I take no sides, but I appreciate what he does even though measurements dont really give you the big picture. At least someone is trying and like Audioholics, which is where I come from and I dont want to say too much on that topic at least try to stop people from wasting money and provide some type of direction.
But I am pretty sure this unit is Pyle producing for amazon with some extra investment cause pyle is a pyle of crap or they just decided to use the same case XD
I would rather a conditioner blow first not my equipment and more filtering may be needed depending on the amount of dirty current in your space and some of us have thousands of dollars invested and I for one want the extra security and I have very good conditioning that does not limit my playback
"more filtering may be needed depending on the amount of dirty current in your space"
Do you know of any measurements that confirm that "dirty current" causes amplifiers to actually produce compromised audio?
You would be relying on luck in that situation. The surge protection devices are voltage rated. The one with the lower voltage will clamp before the higher voltage one. So for all you know, the one inside the amp may clamp first leaving the external one useless.
@@tomterrific9459
It's very simple. Take a portable player with build in speakers and listen on power from batery and next plug in a charger. Difference is pretty obvious.
U may use a smartphone and blutooth speaker, but dont forget plug in charger to phone also. If it possible use a cable conection beetwen devices not a blutooth, cause wireless is also a partial filter of the noise.
Sound powered from batery is less nervous and more smooth and clean.
Power quality varies widely and expecting any device to protect itself from this is pretty much a crap shoot. The consumer is fed all manner of marketing hype and lies about this. A real review about what is coming in to your house would at least give the audience some perspective. You will give it an honest perception as few others will!
Thanks for the trust. More videos on power/power quality will be coming.
Sir, you have extolled your hearing and the precision with which you can distinguish attributes of sound. You would have been a true PIA to ever sell 'Manager's Specials' to. It does cause me to want to remark about all the rest of us.
Nearly everybody can run a mile with a bit of training. But only a few will run it in less than four minutes. Those folks deserve the BEST of equipment, coaches, etc. to better themselves. While the rest would perhaps get SOME benefit with intensive investments, the degree of the return on effort would be less and for most MUCH less, than for the small band of swifties or Golden Heels.
plebeians
I guess I am missing your point here...........???
@@tomterrific9459 It is unlikely that we all require the absolute bestest ever stuff. You are biologically and therefore inherently unqualified to appreciate it.
Your 'betters' may. I know I'm not in that class. Therefore I pay for what I CAN use. It's my recommendation for anyone.
I am easy to sell to actually. When they push that I buy this and that cable, I tell them if they drop the price and include them for free, I would. Two thirds of the time they do! That is how I own a bunch of high-end transparent cables and such. :) Sales people are incentivized to sell these high margin products so they happily drop the price on the main unit to make more commissions.
I have even done this when buying mattresses. Negotiated a price and then the guy wanted to sell me insurance. After telling me that was the best price they could give me on the mattress, the salesman happily took the price down enough to include the extended warranty!
@@AudioScienceReview I did sell audio and yes we did. When the big box stores came about, our boutiques died and I got a real job....eventually.
@Douglas Blake One of the weirdest physiological facts about ears, we can hear (well, SOME) the thermal noise of the ambient air. This article isn't killer technical but explains why, once you wrap your head around it, the entire audio industry is a mess. It's because hearing is so very much individualized and therefore independently subjective. Every consumer presents an unique challenge. We are not buying dish washers.
My challenge to anyone on ASR, is to show me that you understand what the following means…
”man has such a predilection for systems and abstract deductions that he is ready to distort the truth intentionally, he is ready to ignore the evidence of his senses only to justify his logic.” Dostoevsky
♥
I started sensing so called golden ears reviewers a bit nervous. Read an article on the Twittering Machines, lol!
#600
Once again you are absolutely right but you don't paint all the picture.
You should tell the people that as with anything in life comes with a price.
You didn't buy a 100k system just because you have the money to blow.
Tell us how it is better than the average 1000 or 10 000 system. What are the measurements that makes the difference ?
Because it sounds too much like a 100$ dac is all someone need.
Same thing with audioholics : the guy preach cables are no important but uses Kimber kables. As a principal he should use zip cords. (In a proper gage ;)
The ones that preach the most on measurements have the best gears in general and the people with entry level systems believes that what you guys are talking about apply to them.
I would like to have a real correlation between the sound we are experiencing and the quality of the gear.
@Douglas Blake I agree 100%.
Where are you in Canada, Douglas? I am in southern Ontario.
@Douglas Blake Well.. Are you saying that Amir's 100K system is to found a cottage industry ? He put non of his wisdom into his buying process ? It is all an eye candy ?
This fight between the "ears believer" and the "mesurements proselytes" is twisting reality so much that people are starting their own reality. Snake oil aside between two product well engineered the one who cost more generally/always offers more. Specially on a scale of 1 to 10.
You just have to see the equipement the man is using for mesuments. It doesn't come cheap.
I'm not saying that a 1k system can't be amazing for the price but common man you gotta know deep inside that's not the top.
I'm not an elitist at all but real quality never comes cheap.
@Douglas Blake No worth for you but let's not play with absolut. It is worth something for another guy and please let's not shame that person because of his preference and taste. The same could be say with wine, cars, house, food,...
When you go to a fine restaurant you pay for the experience.
And building a system doesn't come cheap. I've done it too countless times. You have to invest in equipements that cost a lot of money to be able to design something at least good technically. It may cost 1K in parts but the labor, the experience, the craftmanship,.. all that is impossible to assess. So saying to newbies well with a 1k system you can beat a 10k system in the market should come with an BIG *.
I don't have ill intent. I just don't like when people uses specific examples and build rules with it like it's the absolut truth. This is what fuel unnecessary arguments, the lack of nuances and no context.
@Douglas Blake and man i'm a DIY guy myself but i don't pretend that my creations can compete with the creations of real experts, real engineers specialize in the domain doing real research and pushing bounderies.
That's another problem with audio. The lack of figures of authority. Everybody thinking they know everything because they have assemble a kit or succed in building a simple single ended amp or a pushpull or a class a/ ab.
It's like building a computer from parts and then thinking you are an IT engineer.
You sure sound like a clever guy and you may have cracked 90% of the system but the last 10% are doing real work and bringing a value that enthousiast people value and pay for it. The first one being Amir !
@Douglas Blake And i totally agree with you. Really all the way !
Higher prices doesn't mean nothing by it's own. There are a lot of overprice stuff in the market.
But we should never generalize to the point of thinking it's the rule.
Appreciation start first with preference which is subjective. Specially in audio some like class A, other tubes, other this and that....But performance is quantifiable and can be mesured. Wether it is appreciated or not is irrelevant when it comes to it in my opinion.
The best build, higher quality materials, low level of distortions, linearity, all the thing we can mesures and that prooves that the product is developped to the highest standard brings directly value regardless of what we personnally think about the product. And those things cost a lot of money.
I've listend to the Crown amp you are talking about. It is amazing and powerfull but personnaly i don't like the sound it produces. a small A/B amp like the Atoll IN30 suits better my taste. Or a Hegel H95 or even a small amp like a taga harmony hta 700b with electro harmonix tubes and better caps in the input signal and coupling.
This is my personal preferences but the argument could be made by saying are they better developped ? No ! But we are comparing Apple and Oranges here.
To be more specific we should compare all the crown amps and see if there is no benefits going from their entry level amp to the top level.
That is all i'm saying, context is very important.
Without even watching the video: NO. Unless you have a very, very badly designed audio device. But VERY badly...
I do not know for more than 500 USD, but for most audio equipment under 500 the PSU is not that well designed, many will not have any filtering at all. most switching PSU do not have any output filtering other than capacitive.
Not one single mention of how this noise can be easily picked up by those of us who have other hobbies such as ham radio. Sorry Amir but not all of us are just audiophiles. We have other hobbies too which need clean power and no RF interference.
The required filtering on the AC line of all devices should keep the noise inside the case. Do you find adding supplemental filtering further lowers the noise being pushed out the AC line?
@@tomterrific9459 yes. Some switch mode power supplies are so electrically noisy that they turn power cords into transmission lines for RFI. This is one of the reasons why some audiophiles turn to upgraded linear power supplies which are not as noisy in the RF band. If you would like more information the ARRL has a great section on their site dealing with EMI and RFI mitigation. Companies like Palomar make filters designed to mitigate this interference. MFJ Enterprises makes RFI sniffers. The biggest culprits are the cheap switch mode power supplies and the poorly designed power supplies in cheap audio gear. You can hear them on ham radio gear and see the interference on a SDR spectrum sweep. I hope this was helpful to you.
oh, if you don't believe the 10 gauge power cord, you're a flat earther
Danny is that you?
This channel makes you believe $1K systems sound as good as $100K system lol
If you got to $100K with these tweaks, you have my sympathy! If on the other hand if you spent it on speakers, proper amplification and such, not at all. My own system costs that much and you don't see me complaining about that. :)
Audio Science Review tests components for how they measure and do not offer subjective evaluation of the sound signature of components. This is not to say that a Krell sound the same as a Rowland which sounds the same as a Denon or Yamaha or Marantz. ASR is Julian Hirach revisited. The reviews are interesting and to be read alongside subjective reviews.
Components may measure the same given the current state of our knowledge of measuring electronics but may sound different for reasons that cannot be accurately measured or repeated.
ASR reviews are not to be taken as Gospel but as one facet of the component’s performance. Just like subject reviews cannot be taken as Gospel as they depend so much of the impressions of the reviewer (system, room, associated components).
Let’s put it this way, at least you won’t spend money on Peter Belt type tweaks or maybe you spend your money of other areas like room treatment that might offer better ROI than these tweets.
@@AudioScienceReview Holy shit Amir I wasn't aware you were a mega baller, damn dude good goin'!
@@navinadv Most ASR reviews do in fact include a subjective listening test towards the end of each review. For instance, in headphone amp reviews, a number of common headphones are tested listening to several recordings, often comparing the sound signature to other similar products.
@@ngtflyer oh ok. I have only read their DAC reviews. That too only a few like the Gustad X16.
HI, Amir, we have sent your email, can reply?
You are funny. You buy cheap , basically junk measure it and tell us noise filters are useless. I have to laugh at some of your posts. Sadly some of the followers actually think you know what your doing.
I find it kind of funny that you think one cap across the AC line in is all you need for filtering the AC in. I guess you never listen to really detailed systems or have done any testing on detailed systems. Next you'll tell people they don't use any ac line filters in recording studios either. Come on, if you're going to do these kinds of videos tell some truth.
You wasted your money on a conditioner, right?
@@MrsZambezi no, but I do have proper REAL filters. Conditioner, haha, fancy word for these manufacturers to use so suckers who think they are audiophiles or have golden ears will buy them.
4:49 ...it probably was soldered well, you likely used too much force pushing it, it was not designed to be man-handled