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Superdad

Amir misses the point again: Looks for the music in the noise.

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1 hour ago, tmtomh said:

What do folks make of the fact that Amir's FFT tests do pick up the dynamic noise products that do make it into the output at the HDMI ports (compared to the cleaner output of the other digital ports)? Do folks think that indicates that dynamic noise products can be measured via FFT?

I will try to give you an answer seeing as no one else is even though you were told to ignore anything I post

 

Unfortunately, this stuff is fairly technical & not easily understandable for the layperson. What Amir shows in the HDMI FFT tests has no bearing on the measurement of noise modulation.

 

 

1 hour ago, tmtomh said:

Also, I am puzzled as to why @mmerrill99 and some others repeatedly seem to impugn Amir's motives (and in the case of mmerrill, to question @pkane2001's motives just for asking questions), rather than running their own tests. If you have a theory that a different, better test will turn up the deviations and noise products that the FFT tests haven't shown, why not put that theory into action?

Well, again Amir talks about technical details & anybody who knows this stuff knows that what he does is post half-truths - the half that supports his viewpoint. He is not trying to find the technical truth as has been shown so many times in the past when he is questioned. So we are left with  one of two conclusions - he either doesn't know what he's doing & doesn't realise the mistakes he is making (but he claims a CV full of technical nous) or he does know what he's doing & is following a particular world view or agenda?

 

As to Pkane2001, my interactions with him here have led me to believe that he has a similar worldview & is not interested in technical truth. He ha 15 years experience with FFTs & says that noise modulation can easily be revealed by setting the correct parameters within FFT. Could I suggest that he shows an FFT of dynamic low level noise modulation that is correlated with signal? This would show that I am wrong & he could inform Amir of these settings & ask him to run his FFTs on the ISO Regen

 

You ask why I don't do these measurements myself? It's because I'm not smart enough to know how to reveal this dynamically changing noise modulation that many conjecture is the underlying mechanism in play here. Many eminent audio designers & electrical engineers others are similarly flumoxed by how to measure this, John Swenson, John Westlake, Gordon Rankin, Bruno Putzeys, etc.

 

So if there is something that all these have missed & it is as easy as Pkane & Amir are suggesting then let's see the details, FFTs & the proof that it is easy? 

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1 hour ago, mmerrill99 said:

Could I suggest that he shows an FFT of dynamic low level noise modulation that is correlated with signal? 

 

So you want me to prove your conjecture for you after all? Sorry, that ship has sailed. Maybe I'll reconsider when you admit to having a vested commercial interest in USB cleansing devices. 

 

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tmtomh   

 

@mmerrill99, thank you for your reply just above. I take your point - and appreciate your candor - that it can be very difficult to figure out how to measure something like the dynamic noise you and others are talking about.

 

At the same time, and putting aside the vitriol, I think @pkane2001 makes a crucial point in his most recent comment above. While I'm sure you would admit, if asked directly, that we don't know for sure if such random dynamic noise exists at the output of some or all DACs, your argument seems to be proceeding as if you were certain. You are acting as though pkane and others have the burden of establishing that such noise does not exist. So it is quite reasonable - at least to my way of thinking - that they would retort that the burden actually is on you to establish that it does exist.

 

To put it in terms of your lamplighter cartoon analogy about looking for a lost quarter where the light is good instead of where you dropped it: The issue that pkane and others are raising, and that I am at least somewhat sympathetic to, is that in this case we don't know where the quarter was dropped, and in fact we don't even know if a quarter was dropped at all. So you're savaging Amir for saying he sees no evidence of a phenomenon that you don't even know exists in the first place.

 

On 8/3/2017 at 3:12 PM, mmerrill99 said:

It's the old Lamplighter effect - measurement bias

muttjeff01.jpg

 

 

 

Thinking analogously of problems in theoretical physics - where for example particles have been theorized to exist without their existence having been confirmed - I would say that we simply don't know unless or until we devise new tests. In that spirit, I have to say that I'm puzzled by your "it's too technical but take my word for it" reply about why Amir's FFT HDMI result is meaningless, given how willing and able you've been to get into the technical details on other points in this discussion, especially with other aspects of why you think Amir's tests are worthless.

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1 hour ago, pkane2001 said:

 

So you want me to prove your conjecture for you after all? Sorry, that ship has sailed. Maybe I'll reconsider when you admit to having a vested commercial interest in USB cleansing devices. 

 

It's up to you what you do but you made a claim that I was wrong & it was easy to measure the type of dynamic noise floor modulation that is conjectured to be in play in the ISo Regen

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mansr   
4 minutes ago, mmerrill99 said:

the type of dynamic noise floor modulation that is conjectured to be in play in the ISo Regen

Could someone please state this conjecture in clear, technical terms?

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16 minutes ago, mansr said:

Could someone please state this conjecture in clear, technical terms?

I'll not bother as this has been done so many times now that asking this is the circus which comes to town at regular intervals

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mansr   
11 minutes ago, mmerrill99 said:

I'll not bother as this has been done so many times now that asking this is the circus which comes to town at regular intervals

Then give me a link.

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Superdad   
35 minutes ago, tmtomh said:

To put it in terms of your lamplighter cartoon analogy about looking for a lost quarter where the light is good instead of where you dropped it: The issue that pkane and others are raising, and that I am at least somewhat sympathetic to, is that in this case we don't know where the quarter was dropped, and in fact we don't even know if a quarter was dropped at all. So you're savaging Amir for saying he sees no evidence of a phenomenon that you don't even know exists in the first place.

 

Thinking analogously of problems in theoretical physics - where for example particles have been theorized to exist without their existence having been confirmed - I would say that we simply don't know unless or until we devise new tests. 

 

There is one data set being overlooked.  One which, while it does not directly and visually show the mechanics of the phenomenon, does demonstrate that it exists. I am speaking of course of the thousands of users of ours and similar products--and the ubiquitous and consistent reports of their efficacy.

 

But for some reason, the pseudo-scientists--rather than acknowledge the observed phenomenon and then collaborate to search for the measurements that correlate--would prefer to cling to non-revealing tests and deny possibilities beyond what they know. Bad science! :/

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mansr   
25 minutes ago, Superdad said:

There is one data set being overlooked.  One which, while it does not directly and visually show the mechanics of the phenomenon, does demonstrate that it exists. I am speaking of course of the thousands of users of ours and similar products--and the ubiquitous and consistent reports of their efficacy.

The plural of anecdote still isn't data.

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Superdad   
25 minutes ago, mansr said:

The plural of anecdote still isn't data.

 

But if 100 people tell you are a horse--and you notice hoof-prints on your carpet--you might consider getting a saddle. x-D

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mansr   
25 minutes ago, Superdad said:

But if 100 people tell you are a horse--and you notice hoof-prints on your carpet--you might consider getting a saddle. x-D

Why do I have a sudden craving for oats?

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30 minutes ago, Superdad said:

 

But if 100 people tell you are a horse--and you notice hoof-prints on your carpet--you might consider getting a saddle. x-D

 

I would suggest that you measure yourself carefully before agreeing with the 100 people.

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plissken   
On 8/2/2017 at 9:39 PM, The Computer Audiophile said:

@mansr The objective information you asked for is here - 

 

 

I've always asked for the DAC that we could see the output improved. And the ISO Regen does that.

 

It's really proof of a few things though and if you take to heart what I posted (since you quoted it) then you need to take what I'm about to post to heart also:

 

1. That's a DAC that is poorly designed

 

2. If the above image is good enough to agree that a regen product does improve a poor DAC then you HAVE to accept that on a DAC where no difference is measured there is no difference

 

3. You HAVE to accept that on DAC where it makes things worse, well things are worse. Look at what the regen iso fucked up on a DAC that was previously fine on computer USB buss power:5984ed75ab2a4_RegenWORSEBehringerzoomedin.thumb.png.2038bd1bb3696fbbf40111046aa0c345.png

 

 

 

 

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plissken   
On 8/3/2017 at 2:59 PM, lmitche said:

I remember telling Amir that an FFT wouldn't cut it after his first bogus measurements of the Amber Regen. He either didn't get it or only has a hammer and the whole world looks like a nail.

 

No, Amir took the step to 100% debunk your claim. He burned your assertion to the ground.

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7 hours ago, Mercman said:

From an anonymous source via Mercman:

 

Arrrrgh!

 

Spectrum analyzers and other test gear (oscilloscopes, network analyzers, etc.) have used averaging for decades.  The intent is to remove noise from the display so that little details can be more easily observed.  In the case of audio spectrum analysis, averaging lets you see itty-bitty distortion products that are often buried in the noise.  You know - the ones that certain folks insist can’t be heard.  (Maybe they can’t - some people are just more militant about saying so than others.)

 

In general, the way this is done is by combining the results of several sweeps or equivalent FFT captures and mathematically averaging the results.  Hence the name.  The idea is that repetitive signals like sine waves will remain constant over those sweeps but noise, being random, will not be.  The noise will shrink to its average value and the desired signal will stick out.  The more sweeps or FFTs you average, the greater the noise rejection.  This works especially well on so-called “white” noise that is truly random.  The average function will display the average value of the noise floor if there is any shape to it.  You can see the shape of the 1/f noise sidebands caused by certain forms of phase noise, for example.

 

That’s all great, but it really is misleading in the overall scheme of things.

 

Why is that?

 

Using averaging tends to get rid of random events, like maybe computer generated garbage that isn’t coherent with the sound content.  That’s the point of averaging.  

 

You could have a pile of crap that’s 30 dB above the system noise floor for one sweep, and if you average enough times over enough sweeps its contribution to the averaged measurement shrinks to nothing because it only happened once.  If the frequency content for a second pile of crap is different from the first and only happens for a single sweep, it gets averaged out.  And so on.  That make sense?  If the pile of crap is consistent over a lot of sweeps, it will get averaged to something that is displayed.  Averaging pulls out what is consistent from sweep to sweep or FFT to FFT.

 

Actual playback of music and other sound isn’t averaged by your ears and brain!  The content changes constantly.  Isn’t that the point?  You hear those changes.  That’s not some secret psycho-acoustic consideration.  It’s just reason.

 

Try turning the Averaging function off.  Enable Max or Peak Hold (depends on the test instrument) and let the instrument capture sweeps for a few seconds.  That should capture most of the random events that take place over that time frame.  Now, report back.

 

Two notes:  

 

The argument that music is composed of sine waves and therefore this doesn’t apply is just wrong.  Music is composed of sine waves, but random and pseudo-random events can be broken down that way as well with an associated frequency spectrum.  This is a measurement consideration.

 

This problem is hardly unique to audio.  Engineers and their buddies use different spectrum analyzers to measure performance of various communications systems.  Wireless and CATV are just two examples.  The signals used in those services are complex modulation waveforms like QAM and OFDM.  (Google those terms if you like.)  Aside from looking at the spectral characteristics, these analyzers can also demodulate those complex waveforms and display the information as data constellations for each symbol transmitted.  It’s customary to average these constellations over a lot of symbols to reduce the effects of random noise.  Just like Amir is doing.  There is a measurement of overall signal called MER.  (Modulation Error Ratio - try Google again)  MER is kind of like SNR, except that it adds in the effects of some other signal degradations in addition to random noise.  It’s used as the benchmark for system performance.  If you sit and watch the constellation display over time, you often see it explode (in a Star Wars kind of way) every so often in most systems.  That indicates that a symbol - sort of equivalent to a sweep of the Audio Precision, except its tied to the actual content - had some problem with it.  You’d think that would affect the MER.  It does, but not by much.  If you completely lose one symbol out thousands, the MER only goes down by a fraction of a dB.  That’s just the way averaging works.  But, if you try doing a Bit Error Rate (BER) test you find that you lost bits.  This despite what the MER would imply.

 

Yes, I used the analogy of a long exposure photograph - the shutter being open for a number of seconds.

The images that are stationery are reinforced on  the photo & will appear sharp, clear & bright.

Say the background light is continually adjusted during the duration of the picture - all we see in the final picture is the total accumulation of the various changes in background light into one background light level - we don't see the variations happening  during the exposure time of the picture.

 

This change in background light will be perceived in the real world when looking at the same scene over the same number of seconds.

 

But if we are relying on the picture as proof of this we won' find any indication of this in the final picture.

 

So this final picture is the equivalent of the FFT - it's showing an average

 

So if this background light is actually an electric light & we are running a very heavy machinery which occasionally draws a lot of current &  causes the light to dim - using this pic as our evidence we will not see this correlation between the machine's current draw & the dimming of the light.

 

So all  those who attest to having seen this intermittent dimming of the light will be told they are imagining it by those who wave the picture of the scene as 'proof'

 

Now what about taking high speed snaps every 0.5 seconds & comparing the snaps for changes in the background lighting? Great, we are getting a step closer. But what if what's causing the machine to draw heavy current is because it has to stop & start very quickly & during our test we just keep it running at a constant speed? Well even with the pics every 0.5 secs we won't see any change in  the backgound lighting. So we need the right inputs to the machine to cause the current draws which cause the lights to dim intermittently.

 

So let's go back to FFTs - the background light is the analogy for the noise floor, it's intermittent dimming is the conjectured noise floor modulation & the input to the system needs to be a dynamic signal, not a fixed tone signal i.e run the machine with stop/starts (for example) not continuously at a constant speed.

 

I conjecture that one possible approach to measuring this may be that we take many short FFTs done without averaging over a period of time when the system is processing the type of dynamic signals which is conjectured to result in noise modulation. But I suspect that there are many obstacles to actually achieving this otherwise it would have been done already

 

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6 minutes ago, plissken said:

 

I've always asked for the DAC that we could see the output improved. And the ISO Regen does that.

 

It's really proof of a few things though and if you take to heart what I posted (since you quoted it) then you need to take what I'm about to post to heart also:

 

1. That's a DAC that is poorly designed

 

2. If the above image is good enough to agree that a regen product and improve a poor DAC then you HAVE to accept that on a DAC where no difference is measured there is no difference

 

3. You HAVE to accept that on DAC where it makes things worse, well things are worse. Look at what the regen iso fucked up on a DAC that was previously fine on computer USB buss power:5984ed75ab2a4_RegenWORSEBehringerzoomedin.thumb.png.2038bd1bb3696fbbf40111046aa0c345.png

 

 

 

 

 

Very interesting. It's strange to see one product where there's an improvement, one product where there's no improvement, and one product where things got worse. I'm not sure what to think of this yet. I still can't get it out of my head how much Amir has a bias against certain products and companies.

 

Perhaps he should be testing all the components he sells and comparing them to the much cheaper options he has tested. His bias and vested interest can't be ruled out in any of his tests. 

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plissken   
4 minutes ago, The Computer Audiophile said:

 

Very interesting. It's strange to see one product where there's an improvement, one product where there's no improvement, and one product where things got worse. I'm not sure what to think of this yet. I still can't get it out of my head how much Amir has a bias against certain products and companies.

 

Perhaps he should be testing all the components he sells and comparing them to the much cheaper options he has tested. His bias and vested interest can be ruled out in any of his tests. 

 

Chris, he DOESN'T have a BIAS against it. Your own quoting of of the screen shot and thread I started shows that.

 

"I" don't have a bias against the product. In my evaluation of like products I could never tell a difference. I even asked Alex directly WHAT DAC could get along with his product and experience this.

 

Don't look for ghosts that aren't there.

 

If you were to ask Amir if he thought regen products didn't work WHAT answer do you think you would get out of him? Go to his forum and ask.

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mansr   
2 minutes ago, mmerrill99 said:

So this final picture is the equivalent of the FFT - it's showing an average

I get the impression that you have only a rudimentary (and that's being generous) understanding of the Fourier transform. And maths in general for that matter.

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1 minute ago, mansr said:

I get the impression that you have only a rudimentary (and that's being generous) understanding of the Fourier transform. And maths in general for that matter.

Fair enough, correct my misunderstanding!

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plissken   
2 minutes ago, mansr said:

I get the impression that you have only a rudimentary (and that's being generous) understanding of the Fourier transform. And maths in general for that matter.

 

I can't take this for gospel, but mmerril is jkeny.

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30 minutes ago, plissken said:

 

Chris, he DOESN'T have a BIAS against it. Your own quoting of of the screen shot and thread I started shows that.

 

"I" don't have a bias against the product. In my evaluation of like products I could never tell a difference. I even asked Alex directly WHAT DAC could get along with his product and experience this.

 

Don't look for ghosts that aren't there.

 

If you don't see a bias and agenda there, I don't know what to say. It's strange to see the headlines of his articles about Alex's product and Sonore products, where the large texts is THIS DOES NOTHING or THIS PRODUCT HAS ISSUES, then in small text in a comment way down the next page, you can read stuff like, oh I screwed up the test (microRendu) and oh I guess this does help with a DA (schiit).

 

Reading his conclusions it's very obvious what he thinks. If he was really into objective analysis he wouldn't editorialize the results with adjectives like he does.

 

Again, where are the measurements of the Berkeley Audio Design products he sells, compared to $100 DACs? He isn't as altruistic as you may think. 

 

It really seems like he is out to hurt the businesses of those who don't help him make money, and those who do get off scott free. 

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