Let me start by saying I like watching Amir from ASR, so please let’s not get harsh or the thread will be deleted. Many times, Amir has noted that when we’re inserting a new component in our system, our brains go into (to paraphrase) “analytical mode” and we start hearing imaginary improvements. He has reiterated this many times, saying that when he switched to an expensive cable he heard improvements, but when he switched back to the cheap one, he also heard improvements because the brain switches from “music enjoyment mode” to “analytical mode.” Following this logic, which I agree with, wouldn’t blind testing, or any A/B testing be compromised because our brains are always in analytical mode and therefore feeding us inaccurate data? Seems to me you need to relax for a few hours at least and listen to a variety of music before your brain can accurately assess whether something is an actual improvement. Perhaps A/B testing is a strawman argument, because the human brain is not a spectrum analyzer. We are too affected by our biases to come up with any valid data. Maybe.
What I take as Amir's main point seems to be lost among the personal attacks on him, most of which appear sadly mis-informed. What I hear him saying to the manufacturers of equipment which does poorly in his tests is "show us your data." Or conversely, "admit that you have no data." That's it. Simple. Then consumers can decide.
What we see from some of the worst offenders is a lot of technical sounding talk which suggests a technical underpinning to their claims but zero data. Did they design their product with no measurements? Perhaps. Then tell us that.
I picture a cable maker for instance that soaks his wires in vinegar then declares they sound better to him. Well more power to you buddy! But if you want me to buy it you don't have to divulge your proprietary secret, just give me something more than techno mumble jumble. If indeed the improvement cannot be measured with current technology (a possibility I am willing to concede) and the manufacturer is not willing to foot the expense of well conducted, objectively fair listening tests to support their claim then I guess it is a true "audiophile grade" product. Does it makes things sound better? Depends on who is doing the listening and what they ate for breakfast and whether they tripped over the dog while leaving the house this morning, I guess.
Oh, the latest PS Audio YouTube is missing the objection to the device they aren't measuring the HC outlets. It's more smoke and mirrors from PS Audio for their fanbois.
I'm not sure where this notion that audio precision is sceptical of their products ability to measure. Are they looking to improve their products? Certainly what company isn't. But if this idea has come about from a YouTube circulating from an engineer from AP then you need to watch it again. He isn't saying their device is lacking in measuring but that some companies cherry pick measurements performed by an AP device so consumers need to be wary when looking at company advertised SPECs which are not the measurements.
1) why do some other independent measurements differ from those of ASR?
2) What happens to the dacs etc when they have been tested.
Re 1) I suspect that certain manufacturers send cherry picked equipment, and Re 2 I do not hink the dacs get returned. Amir needs to make a living after all.
Someone can be anti-science using some scientific tools at his disposal...science is also about conceptual tools linking some field to another field...
Especially in audio where acoustic and his relation to psycho-acoustic is no less a science than electronical technology when we try to UNDERSTODD listening experience...
Audio science is no more fetichism of the tool than fetichism of the gear......
Objective measure are not only around the gear they can be around the speakers/ears/room serving the subjective perception of the timbre experience for example ....
This possibility seems to escape "our si called scientists" here....
I’m ready glad that audio precision doesn’t think like the objectivists on this forum, they actually think there is more or better measurements that can be performed in the future to better understand what we are hearing.
So you are against the idea of searching for a better and more reliable understanding of what we are hearing?
That sounds like flat-out anti-science.
I’m glad there are people out there trying to investigate these things, rather than
being happy with our current state of understanding.
I'm ready glad that audio precision doesn't think like the objectivists on this forum, they actually think there is more or better measurements that can be performed in the future to better understand what we are hearing.
So you are against the idea of searching for a better and more reliable understanding of what we are hearing?
That sounds like flat-out anti-science.
I'm glad there are people out there trying to investigate these things, rather than
being happy with our current state of understanding.
This is the problem I mentioned earlier. I do not believe that either Amir or the folks at PS Audio know exactly how all possible distortions (and time delays, phase changes, noise patterns, filter slopes, audible effects that change with frequency, etc.) interact to affect the sound quality the human brain hears and interprets. Thus, SQ cannot be assessed using measurements alone. Listening must be part of the assessment.
Great post indeed! thanks very much....
And particularly these 2 lines...
I do not believe that the folks at ASR are omniscient, and I also do not believe that the folks at PS Audio are trying to rip-off their customers.
Amirm is coming to the question with knowledge about what type of distortion is possible, and what type of distortion is audible (given known thresholds of hearing).
If there is some OTHER form of distortion Amirm is not measuring for that would be audible...what would that be?
This is the problem I mentioned earlier. I do not believe that either Amir or the folks at PS Audio know exactly how all possible distortions (and time delays, phase changes, noise patterns, filter slopes, audible effects that change with frequency, etc.) interact to affect the sound quality the human brain hears and interprets. Thus, SQ cannot be assessed using measurements alone. Listening must be part of the assessment.
My summary of the P12 review on ASR is that Amir agrees that the P12 cleans up the waveform, as PS Audio intended, but that he can't measure any changes that he believes could improve the SQ when an amp is hooked up to the P12. Of course, Amir doesn't think listening is needed because he thinks his measurements tell the whole story. In contrast, PS Audio has measured and listened to the P12 during development of the product, and most users report hearing major improvements in SQ when using the P12, especially when there are significant problems with the power being supplied to the P12.
I do not believe that the folks at ASR are omniscient, and I also do not believe that the folks at PS Audio are trying to rip-off their customers.
I'm ready glad that audio precision doesn't think like the objectivists on this forum, they actually think there is more or better measurements that can be performed in the future to better understand what we are hearing.
If there is some OTHER form of distortion Amirm is not measuring for that would be audible...what would that be?
I am pleased to inform you that the distortions coming from the room geometry, topology and acoustic content pairing with a specfic audio system is very powerful impediment to S.Q.... More powerful than comparison between relatively good electronic design subtelties measured by Amirm tools..
"Gear brand name subjective fetichist" like "tool objective measuring fetichist" ignore acoustic and psycho-acoustic and take the ears/ room to be unimportant way less than a decimal in THD+N amplifier specs for example...
This is called losing sight of the tree looking for an ant....
Yes it is useful to see an ant on a tree....But it is foolishness to never pay attention to the tree..
Distortions is not an electronical notion "per se" it is first and last a psycho-acoustical notion...Electronical design distortions concept come from the measured hearing human range perception and qualitative evaluation and subjective judgment guiding necessity ...
No piece of gear sound the same in different rooms...
An anechoic chamber is an experimetal room not a listening room..
There is no STANDARD room, all small room are different and own different acoustic positive and negative potential..
Then evaluation of an audio product not only is relative to human ears "specific" innate distortive potential working and history but related to specific room negative and yes, unbeknownst to most, sometimes to the positive effect of some distortions when they are controlled in some range and timing ratio for psycho-acoustic reason and experiment...
Acoustic is at least at the same level of complexity than basic electronic ...
I dont speak about common rule of placing acoustic panels on a wall here when i speak about acoustic... 😁😊I speak about something a bit more complex to say the least...Physical acoustic and psycho-acoustic of small room is not less complex than amphiteater acoustic architecture but in fact perhaps more complex because it must be designed for a specific audio system only and for the singular pair of ears of the owner room......
« Look at the tree on the back of the walking ant »-Anonymus Zen monk
Prof, with all due respect, Amir’s approach still assumes that he is measuring everything that matters in terms of ultimate sound quality. I think that is unlikely to be a valid assumption. If Amir’s assumption of perfect measurements is invalid, then the importance of human listening cannot be excluded from any evaluation of a product designed to improve the sound quality of reproduced music.
Amirm is coming to the question with knowledge about what type of distortion is possible, and what type of distortion is audible (given known thresholds of hearing).
If there is some OTHER form of distortion Amirm is not measuring for that would be audible...what would that be?
Shouldn’t PS Audio have identified just what that distortion was...if they even came up with a solution for it?
Yet PS Audio isn’t telling us they’ve identified some unknown type of distortion. They are saying their product fixes the AC power in standard ways that any engineer can understand...and test for! Which Amirm did. Amirm tested the effects of the regeneration on the power AND the effects with an amp hooked up.
What else could he possibly test? Simply waving at Some Mysterious Yet To Be Discovered thing no more helps PS Audio claims than it does anything at all.
As to Amirm not performing blind tests, I agree those would be a nice addition.
But given the objective evidence already showed distortion differences known to be inaudible, there isn’t any good reason to presume they’d be audible in blind tests.
PS Audio could, of course, always show otherwise. But we know they won’t. (The best inference being: because they couldn’t demonstrate any mysterious unmeasured audible distortion).
I too appreciated Amir effort and journey with his tools and investigations...
I went on his site and even try to participate few years ago...
But i guess i did not appreciate the ideology of his vast court of disciples attitudes toward listening experiments at all...And sarcasms instead of an opened spirit...
I never go back... Why ?
Because we choose a piece of gear not mainly by numbers, measured numbers are only the necessary beginnings but the last word about choice of gear is by listenings or/ and analysing ton of reviews or others opinions....
Amir is honest to himself and do what he want to do and it can be useful because he inquire about claims yes......
But "the measuring tool fetichism" ideology of his disciples crowd worsen and impede listening experiments in acoustic and psycho-acoustic by making belive to people that the S.Q. results come more from the gear specs itself than the link between the system and the room/ears acoustic and psycho-acoustic relation...
The "tasting gear brand name fetichist" group and the "measuring tools gear fetichist" group are linked together by the same underestimation of ears/room objective acoustic and subjective psycho-acoustic CORRELATION experience and experiments...
Consumers are conditioned by the market like the RCA dog listening directly the gear pavilion or reading some numbers on a dial like the dog master without NEVER analysing the relation between the system as a whole the specific ears and the specific room...
i am a free thinker and i dont like groups...Anyway....😁😊
i admire Amir for sure but despise "yes man" then i cannot stand the disciples attitude toward something OUT of their perspective ....I am human myself and far from perfection...
I don’t own speakers recommended on ASR but I do appreciate the effort put forth by Amir in his speaker testing it gives one a good look as to if the speaker has been properly designed and how well it can be adjusted by DSP. How you like speakers to sound is entirely your own preference.
You have to live with something for an extended time before a judgment can be made as to its worth. Comparative experience is also required to make any meaningful statements regarding the performance of any gear. Measurements can tell you what something is doing electronically, but it can’t tell you how it will sound to your ears in your system.
Speakers are measured on a Klippel and are usually listened to in mono. Amir's listening part of the review is his opinion and in no way meant to influence your purchasing. I don't own speakers recommended on ASR but I do appreciate the effort put forth by Amir in his speaker testing it gives one a good look as to if the speaker has been properly designed and how well it can be adjusted by DSP. How you like speakers to sound is entirely your own preference.
A video telling people they are reviewing speakers incorrectly, suggesting the importance of DBT, by a fellow who does sighted listening evaluations against a single DUT while having already seen the data.
People are missing the point of these reviews. Amir tests the Product, shows the measurements are the same or different from like products or engineering standards . Explains hearing thresholds and says in HIS OPINION there likely is no or little difference in music reproduction and places the product on a scale of similarly measured products. It's not his job to tell you what to buy or if you can hear a difference but if you claim to hear a difference in similarly measured products the only way YOU can rule out YOUR inherent biases is with a properly controlled test.
Amir's approach still assumes that he is measuring everything that matters in terms of ultimate sound quality
I don't see that, he's measuring the DUT and seeing if it does what the manufacturers claim it does.
Amir talks up the value of unbiased listening tests, but then admits that he is clearly biased and unwilling to go to the trouble of setting up any unbiased listening tests himself.
Why would he set up BDX testing of a component that doesn't do what's claimed? It isn't his place to conduct a DBX but those who claim the component does things the measurements clearly show isn't possible.
Prof, with all due respect, Amir's approach still assumes that he is measuring everything that matters in terms of ultimate sound quality. I think that is unlikely to be a valid assumption. If Amir's assumption of perfect measurements is invalid, then the importance of human listening cannot be excluded from any evaluation of a product designed to improve the sound quality of reproduced music.
Amir talks up the value of unbiased listening tests, but then admits that he is clearly biased and unwilling to go to the trouble of setting up any unbiased listening tests himself. That is the bit that is missing from most of Amir's reviews, including his P12 review.
It was completely predictable that PS Audio's damage control video would miss the point.
These companies always make claims that attaching your gear to their product "dramatically improves the SOUND of X, Y and Z in your system."
But they never DEMONSTRATE any measurable - or audible - change in the SIGNAL COMING OUT OF GEAR ATTACHED TO THEIR PRODUCT.
It doesn't matter much if you are "correcting" for problems that are either generally corrected for in the design of lots of gear (e.g. amps) or that are not audible in the first place.
THAT was the point of Amirm's review. Amirm showed that, yes, the power plant DID regenerate and regulate the power IF YOU JUST MEASURE at the power plant. The question was "But what BENEFIT are we likely to see when you attach an amp?" That's what Amirm did, showing there was essentially no benefit likely to make any audible difference.
This is, of course, precisely the issue the new PS Audio video avoided. They just did the usual "Look how our device alters the power" and then IMPLIED that this has the audible benefits they claim. It's that last bit they are missing.
For those who are interested, Paul McGowan has put together a video on the PS Audio forum that explains what the P12 regenerator does and how to measure it correctly.
It appears you have not gone through that second review.
Amirm DID originally do tests on the other Zone A outputs, but only used the last outputs for the amp on the very rational inference that since they were labelled "high current" those would be best for powerful amplifiers. The owners manual tells the user the voltage output is the SAME ACROSS ALL ZONES so there is nothing to suggest any problem with using the zone D outputs.
It's entirely PS Audio's fault for this lack of information for the user.
Paul McGowan didn't help with information by claiming the D zone didn't regenerate power, so Amirm shouldn't have used it. Amirm's own measurements showed Paul was wrong, that it DID regenerate power. Paul later admitted to the mistake.
So the source of accurate information here has been Amirm's measurements, not the user manual nor the company spokesperson!
No user, or prospective customer, would likely know any of this without Amirm having measured the unit.
Further, as I understand it, PS Audio never reached out to Amirm to try to "correct" anything in the review. Rather, Amirm was alerted to some dialogue in the PS Audio forum criticizing his review. So he took it upon himself to take another look addressing the criticisms and the additional claims made by McGowan in the thread. THAT is actually being a conscientious reviewer! But of course you apparently don't want to give him any credit possible.
Plus Amirm showed that even the other zones regenerating power did nothing to help with amplifier power/dynamics or anything that would support the company's claims for how it will elevate the sound quality of your system.
A perceived acoustic QUALITY is not REDUCIBLE to ONLY a specific range of frequency perception...There is more than that to explain this quality...
Timbre is not even describable in only a spectral envelope ...There is 5 factors in the most elementary description of timbre...
Imaging, soundstage, listener envelopment has nothing to do with BAT ears superhuman abilities , it is possible to perceive them for any average human healthy ears of any age who learn how to listen and how to implement the acoustic conditions for their perception...
It sems some "measuring tools fetichist" dont know even basic psycho-acoustic...
Then if someone perceive something not reducible to a measured quantity they speak about "bat super human " ability to mock the perceived change in the perception of an instrument timbre for example...
take a simple experiment: put a big chunk of quartz on your amplifier and after that put a big chunk of shungite.... And take a blind test to assess the change in S.Q. .... It will be easy to pass it... Try it at home...It is only a test to demonstrate an acoustical effect that the ears measure more easily than any other tool....It is a test more easy to do than a scientific blind test.... Science progress dont wait for blindtest...The industry need blind test not science...Audio can use blindtest for sure and already use them with succees but reducing all perception real experience to be real only after a public blind test is ridiculous...
Objectivist Tool fetichist or subjectivist gear fetichist ignore acoustic and psycho-acoustic complex relation ...And ignore some simple experiments save blind test they want others to pass...
Tone is not timbre....
Frequency is not timbre...
And decibel scale dont say all there is to say about hearing ability and timbre....
Human ears can sense the qualities linked to a resonant sound source, and we listen to capture these qualities ... We can "measure" if a fruit is ripe or not by tapping on it.... Blind people SEE with sound... And their ear are average like mine is....
The fashion up to date now is "blinders" of their own making it seems among tool fetichist and gear fetichist....They argue about their blinders ....
I feel alone without blinders or at least without the same blinders.... 😁😊
Regarding the PS "review." Science is based on replication and peer review. If the output used didn't measure correctly, why wouldn't a site with "science" in their name not test another outlet to verify results? It's lazy. Or reach out to the company and ask them about the different outlets. I don't use Powerplants, so I can't comment on whether the manual is lacking information or not. Maybe the support forums clarify best use practices? These are sophisticated products, and not necessarily plug and play.
I reached out to the designer of my power conditioner to inquire about a few things, and I'm end end user, not a "reviewer."
If someone wants to be seen as a legit source of unbiased information, they need to do the work to gain that level of respect, and a fake science site that (I believe) is also an audio dealer, is not that.
Amir does us all a great service with his site and all the testing. I rarely find fault with any of his useful illustrations. Go Amir!
The problem with Amir is what comes after the measurements. I want to know what he found but when he begins the inevitable explanation of how anything beyond 20-20K and below -60dB can't possibly be heard--I start wetting my pants.
I know that's MY problem but it's a cause/effect that limits watching him.
A blind listening test is not a test for bias.
It shows that listening under those conditions is mostly more difficult, but it does not explain WHY it is more difficult.
I’m unclear on what you are saying. On your account: What about "listening" is "more difficult" under blind test conditions?
Also, why would Amir not be biased himself? Maybe he does not want to hear (or accept) a difference?
Especially when it comes to vetting a controversial technical claim for audible differences, Amirm’s sighted impressions are no more reliable in of themselves than anyone else’s.
That’s why in principle anyone who BELIEVES he hears a difference could test themselves (using blind testing to help rule out sighted bias).
That said, Amirm’s sighted impressions are at least backed up pretty heavily by the objective evidence he presents. Unlike the usual audiophile anecdote or audiophile marketing.
Also, as we still not completely sure WHY we experience differences in cables, who is to say he is even measuring the right parameters? What if our brain can detect the differences? How will we measure that?
To be clear: I am not saying he is wrong, but I am suggesting that there are too many questions left unanswered to conclude that he is right.
By that measure you couldn’t establish any conclusion!
The best we ever have is what the evidence suggests.
First of all, we can test whether your "brain" can detect any differences via blind testing. If sighted bias and knowledge are ruled out, and you are ONLY able to use your hearing and you can not reliably detect a difference between A and B, then it’s reasonable to assume you aren’t detecting any difference.
This is how standard audiograms/audio tests work for hearing, right? If you can’t reliably detect tones over 12k, guess what? You can’t hear over 12k even if you CLAIM to or believe you can or not.
Similarly all sorts of tests have been done to establish the parameters of most of our senses, including hearing. Once you are down to a certain level of distortion, nobody has shown they can reliably detect it hence no reason to think we can hear it. It follows that if you measure a device and the distortion levels in various relevant parameters don’t rise above the known audible threshholds, then the reasonable conclusion is "that distortion is not audible."
We aren’t beholden to any person’s claim to have Super Human Hearing..unless they can demonstrate it in similar controlled tests.
The engineering involved, the principles on which USB cables are designed, tells us that any competently designed USB cable will transmit the 1s and 0s just fine, especially when used with a competently designed DAC. And that heroic measures beyond that are rarely needed (and in any case, would be unlikely to be responsible for the sonic claims made on behalf of those cables).
Amirm tested for ANY way the Nordost cable altered the signal, looking for any relevant distortions, and there was nothing relevant to distinguish it’s performance from a cheap amazon cable. Before someone says "But we can HEAR the difference so maybe he’s measuring the wrong thing" you should be able to DEMONSTRATE you can hear the difference to take that claim seriously. And that would be under conditions controlling for your knowledge of which USB cable is being used. Otherwise it’s just begging the question.
A blind listening test is not a test for bias.
It shows that listening under those conditions is mostly more difficult, but it does not explain WHY it is more difficult. People are quick to jump on the bias train, but this may not be correct.
Also it may be a bit pedantic to assume that experienced audiophiles can’t distinguish between music mode and analytical mode.
Also, why would Amir not be biased himself? Maybe he does not want to hear (or accept) a difference?
Also, as we still not completely sure WHY we experience differences in cables, who is to say he is even measuring the right parameters? What if our brain can detect the differences? How will we measure that?
To be clear: I am not saying he is wrong, but I am suggesting that there are too many questions left unanswered to conclude that he is right.
I will add that not only aural memory can be improved but also must be learned with the body sensation not with only the brain or the mind but with the heart... Why?
Because mechanisms of memory are linked to perception and interpretation of sound which are themselves related to the feeling body and are stored in this body not only in the brain or mind...
The sound of a duduk is unmistakable for example and provoke a feeling you will never forget, same with the chinese Erhu, wich are insruments with a timbre linked to an innate feeling so powerful we cannot forget it....Same with guitar, organ, piano etc....Any sound is associated with a distinct feeling varying in each of us for sure but not so much, it is the reason why music is a universal language...
Each instrument is deep in meaning and unique like a human voice....
It is the reason why doctor can reach alzheimer patient with music and for a moment ressuscitate a true part of them from oblivion...The sound feeling perceived by their body BEFORE their mind even interpret it, ressuscitate their consciousness for a fleeting moment by association with their past experiences with music...
It is the reason by "measuring tool fetichist " often claim that sound memory is measured in few seconds and cannot be remembered... This is not false, this is only an half-truth used for "ideological" cultist motivation...
For sure a bit of sound WITHOUT MEANING detached from our usual environment and detached from strong feeling cannot be remembered well...Pick a sound meaning you very well know by "heart" not only mind, and listen continuously IN A RELAXED condition to it in your usual environment and you will KNOW and DETECT any change in the sound qualities...Even if you had not listen some piece of recording for weeks and you put it after having changed the acoustic of your room you may detect huge change... i just live that a few minutes before writing this post myself with a recording i know by heart but which i did not listen to for a few months...
it is my own experience and experiments...
How do you think i was able to tune mechanically adjustable100 Helmholtz tubes resonators and diffusers in my room ?
No i am not a bat nor a " golden ear".... I know my hearing are the hearing of a 70 years old man in health for sure but...But we memorize acoustic MEANING in our body/brain not ONLY brute meaningless sound measured in Hertz and decibels...
I was able to tune my room with my feeling and perceptive memory, stored in my brain/body of what must be a natural timbre...For sure it is not perfect.... Timbre perception is a SUBJECTIVE phenomenon in psycho-acoustic... But there exist OBJECTIVE acoustical conditions necessary to be inplemented to generate a more natural timbre perception...The rest is my CORRELATION process between many objective preparation and disposition of the room and my subjective apparatus..
Aural memory is the result of a learning process, and an ability that we can develop just as any other cognitive function. Improving it is the same as learning a new skill.
When there is effort put in, it can be vastly improved upon, and conversely, lack of training will result in the decline of aural memory faculties.
Just as we can remember words, colors, pictures, we remember sounds with analogous mechanisms. A person who can retain a 7 digit number for 10 seconds can train to withhold it in memory for an hour or longer, eventually retaining the ability to call back the number after a longer time period, and with increased digit counts.
Same with aural memory.
As every learned skill, it takes a lot of effort....some people have a head-start, but ultimately perseverance is key, and is the secret to a good aural memory.
A/B test cannot substitute an acute aural memory.... perhaps with an A/B selector switch we can cut out the time-caused retention-loss... yet, in case the aural perception and memory is so poor that it fades in seconds, then the detail observation skills are also comparatively abysmal. In consequence, the A/B tester with poor aural skills does not have the cognitive faculties to perform the test in a competent way.
Aural memory is the result of a learning process, and an ability that we can develop just as any other cognitive function. Improving it is the same as learning a new skill.
When there is effort put in, it can be vastly improved upon, and conversely, lack of training will result in the decline of aural memory faculties.
Just as we can remember words, colors, pictures, we remember sounds with analogous mechanisms. A person who can retain a 7 digit number for 10 seconds can train to withhold it in memory for an hour or longer, eventually retaining the ability to call back the number after a longer time period, and with increased digit counts.
Same with aural memory.
As every learned skill, it takes a lot of effort....some people have a head-start, but ultimately perseverance is key, and is the secret to a good aural memory.
A/B test cannot substitute an acute aural memory.... perhaps with an A/B selector switch we can cut out the time-caused retention-loss... yet, in case the aural perception and memory is so poor that it fades in seconds, then the detail observation skills are also comparatively abysmal. In consequence, the A/B tester with poor aural skills does not have the cognitive faculties to perform the test in a competent way.
What people like @Prof are ignoring is that according to PS Audio, the fake science site (my term) measured the wrong AC output. Has anyone seen them publish a revision or retraction?
I’m not ignoring anything: it seems you who is leaping to uninformed conclusions.
Did you not see that Amirm did a follow up review taking on all the issues that cropped up after the first one?
The problem wasn’t Amirm; it was that PS Audio’s own user manual made no mention of a difference between the ports, that one was limited in any way, and Amirm did what any user would be likely to do: use the port labelled ’High Current" for their amps. Nobody could fault Amirm for not knowing information PS Audio themselves didn’t think to put in the user manual! In fact it was due to Amirm’s review in the first place that PS Audio customers are now alerted to the fact plugging their amp in the High Current outlet can reduce amplifier power! That's not info PS Audio was telling their customers for that model!
Then Paul came out saying Amirm should apologize for the mistake...while Paul himself was stating misinformation about he product (as shown by Amirm’s measurements) and Paul later admitted screwing up.
In any case Amirm DID take all the brew-haha to heart and did a follow up review addressing the criticisms. Spoiler alert - still no sign the PS Audio device would do what it claims for the *sound* of most amps:
What people like @Prof are ignoring is that according to PS Audio, the fake science site (my term) measured the wrong AC output. Has anyone seen them publish a revision or retraction? Any legitimate site or journalistic source would immediately publish a retraction and retesting with new findings, Or at least a response from the manufacturer stating they measured the wrong thing. Will it happen? If a fake science site ignores their huge technical mistake, then they have no legitimately or integrity and completely invalidate their entire “testing and “review” process.
But hey, if it makes people feel good about the cheap gear they buy that “tests” better than more upmarket gear, it’s their prerogative to scream “snake oil” as I have seen on the few times I wandered over to that cesspool.
Also I have read in this thread that people don’t have a good aural memory, which is why AB testing is required. While this is most likely true, it’s not true for everyone. Many of the people in tests for cd quality vs. hires couldn’t hear a difference, but that doesn’t mean trained listeners can’t hear the difference, or can’t remember characteristics of sound over long periods.
When not handled properly, obsession with A/B tests is just as any another obsession turned into compulsion: harmful and self-sustaining. It ultimately stems from 1., lack of self confidence 2., lack of experience, 3., trust issues.
With these issues solved, it becomes meaningless whether you do a change blind or seeing. (Plus, you need follow up for it to work - break in period, different genres, susceptibility to line AC changes, etc, so just swapping as a form of A/B test is shallow at best.)
When listening to music / system, I just open myself to experience without pre-judging the system. Why? Because I heard cheap solutions punching heavy weight and ultra-bucket mortars turning out as duds, and one piece that sounded like a rust bucket singing in another system. I learned that we cannot bring a single preconception to a listening experience, and I have zero trouble accepting that.
So, go in with zero conceit and preconceptions. Seeing the box that I will hear will bias me to judge it AFTER the hearing on a different scale. (Should have done more or punched high above the weight).
After all you only truly need an AB test when you are a MANUFACTURER and you want an edge to sell.
Supposed i have been a member of an astrological society for 20 years....Which is not the case anyway but supposed it is the case....
There is no difference between us if we are the two of us FREE THINKER first and last....
if not, we are cultists...
There exist groups of people and associastion partaking common interest, in them or outside of them there exist free thinkers...Nervermind the group...
The most important word concept in audio world is: CORRELATION between the subjective impression and some external objective disposition...
The measuring is not enough... Perceiving is not enough.... We must correlate them to IMPROVE the two at the same times...Like it is necessary to learn how to correlate by meditation the two main part of our brain hemispheres and we must learn how to CORRELATE our focus and peripheral attention.... Then unlike the RCA dog we must also learn how to listen with our subjectivity and measure the room not only the gear brand name.... 😁😊
No one can contest the useful analysis of gear made by someone like Amir...
The problem is in the IDEOLOGICAL general stance...
No one can contest the importance first and last of perceiving subjectivity by audiophiles...
The problem is in the general IDEOLOGICAL stance...
Amir like an audiophile look at the gear not at the room...The focus of their attention in the two groups is the brand name gear, one measure it the other think he hear the gear alone and taste it...
Acoustic is forgotten by the two groups...is it not comical?
I myself experimented the fact that most of PERCEIVED S.Q. is an acoustic and psycho-acoustic phenomena...Not mainly an electrical engineering one...
Then correlating objective measures and the guiding subjectivity at play is the crux of the matter...
Anyway i dont use non acoustical tool , i am not an electrical engineer, and i know that sound dont come from the gear alone in my room but from the gear+room...
Then i stay mute when the 2 cultist groups will battle between them but it is difficult to stay silent for me....
The two group are the same RCA conditioned dog, sometimes he listen directly to the gramophone and sometimes the dog measure it oblivious each time of the room acoustic and psycho-acoustic phenomena...
the two groups are the results of the same market conditioning...
Years ago, they were militantly claiming that changes to the power supply of dvd/blu-ray players could not possibly have any effect on the video output, because bits are bits and the power supply does not effect the bits.
Given HDMI has been the default transmission method for many years, that claim is correct. Luminance information, like color and other picture values, is encoded in the digital signal.
It is NOT determined by the power supply to a blu ray player. A pixel on the display either receives the information or it doesn’t. (And when it doesn’t, artifacts can occur but they are not of the type you are describing - a rise in brightness level or color saturation of the displayed image).
It was a theoretical argument,
LOL, no it wasn’t. It’s literally how digital video information works - which is shown in practice millions of times a day (at least). If it didn’t, we would be having a heck of a lot of image problems that we just aren’t having.
which was easily disproven by doing any changes from SMPS to LPS, which on the meter would measure visible changes in brightness levels, let alone color measurement differences and detail improvements.
I call B.S.
Show me the evidence you are speaking of where (I presume using HDMI) changing the power supply to a blu ray player measurably altered the brightness, color etc of the image.
I’ve been a member over at ASR forum for 20 years, where professionals and dedicated enthusiasts have been exchanging notes on calibration - using all sorts of sensitive equipment - and NO ONE has reported anything like that, nor any measurable changes between two properly functioning HDMI cables. Because....that’s not how it works.
And it’s just this type of nonsense that we can be thankful there are people like Amirm around to test.
The problem like i said is not Amir himself, but his disciples crowd... Testing gear by measuring tools is not the same as participating to an ideological cult....The problem was never Christ but his successive fanatical disciples...
Tool testing obsession reductionism is not better than gear tasting brand name subjectivism...
Reality is not binary game and i know that you know it for sure....
And of course as I’ve argued many times, no audiophile has to pay any attention to measurements or science - we can all buy whatever we want, for whatever reason.
But Amirm is providing some extra information for those who seek it, which is great.
Amirm is doing a terrific service to the audiophile community.
You don't have to bow to him as a "cult leader" (ridiculous meme going around) or believe everything he says is beyond critique. His reviews are quite well vetted even on the ASR forum, where his methods and conclusions are examined.
But taking on manufacturers claims and to the extent possible examining what objective evidence can be gleaned or not in terms of measurements is providing one hell of a lot more information than we are finding in most other places (manufacturer's marketing most of all).
There is a part of the Golden Ears crowd who have an almost mystical belief in their own incorruptible, observational powers - "science can't tell me I'm wrong! I EXPERIENCED IT." Those people will likely never be reached.
And of course as I've argued many times, no audiophile has to pay any attention to measurements or science - we can all buy whatever we want, for whatever reason.
But Amirm is providing some extra information for those who seek it, which is great.
Acoustic did not is reducible to psycho-acoustic science...
Psycho-acoustic science dit not reduce itself to acoustic...
Great posts thanks.... Gear fetichist tasting group and measuring tool fetichists perhaps will understand something....
We cannot measure the difference between a middle C, played on a properly tuned clarinet vs. a synthesizer, vs. a trumpet. Your brain knows which is which immediately. Just like humming the note and singing out, wide-mouthed would measure identical, but you know they sound very different.
Nor can we measure the vibrations our body picks up from places other than our tympanic membrane. (bones, hairs, nerves) Spatial awareness in ingrained in us through evolution. A noise, rustling in the grass on the savannah is a matter of life and death. Our ears are only a piece of the "listening" equation.
I’ve played with EQ and a spectrum analyzer to make the response curves of Magnepans and Klipsch horn-loaded box speakers measure the same in my seat ...and they sure don’t sound identical, though no frequencies are missing.
No measurer can ever tell you which one, out of 2 pieces of gear sounds better. (however you define it.
A timbre is not a tone...A playing tone is made of two phenomenon then...
It’s trivially simple to measure the difference between a clarinet and a trumpet.
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