New Nordost Heindall 2 USB

[gmgraves]

OnThe search for understanding is admirable for sure. To deny experience based on lack of comprehension of the possible mechanisms behind it is to say the experience is not genuine without the understanding. Something there seems backward to me. (Almost as odd as denying the possibility that *others* can have experiences even though we don't and/or we cannot explain them.)

 

Just my perspective, of course.

 

Best regards,

Barry

Soundkeeper Recordings

The Soundkeeper | Audio, Music, Recording, Playback

Barry Diament Audio

 

I agree. But what we are talking about here is a phenomena that, in the realm of possibility, in my opinion, is the audio equivalent to the belief in ghosts*. Many people say that have encountered ghosts, have seen them, and even have some sort of relationship with them. Now that's possible, because we, as living humans know nothing about ectoplasm and other spiritual things but it is highly improbable.

The chance that ghosts exist, however, is far more likely than USB cables having a sound or that burning said cables in will change that sound, because unlike the hereafter we do know how digital audio works and why digital audio works. Also, if USB cables change digital data, why don't documents and computer applications sent over USB get "changed"? After all, documents, programs and digital music are all merely data, ones and zeros. If USB cables are altering sound and not other forms of digital data, how do it know the difference?

 

* Yeah, yeah, it's an odious comparison, but what can I say?

[drez]

I agree. But what we are talking about here is a phenomena that, in the realm of possibility, in my opinion, is the audio equivalent to the belief in ghosts*. Many people say that have encountered ghosts, have seen them, and even have some sort of relationship with them. Now that's possible, because we, as living humans know nothing about ectoplasm and other spiritual things but it is highly improbable.

The chance that ghosts exist, however, is far more likely than USB cables having a sound or that burning said cables in will change that sound, because unlike the hereafter we do know how digital audio works and why digital audio works. Also, if USB cables change digital data, why don't documents and computer applications sent over USB get "changed"? After all, documents, programs and digital music are all merely data, ones and zeros. If USB cables are altering sound and not other forms of digital data, how do it know the difference?

 

* Yeah, yeah, it's an odious comparison, but what can I say?

 

That's cool but this is getting way off topic. This thread is for discussing the Nordost Heimdall 2 not whether or not we are skeptical about USB cables having an audible difference. My 2 cents is we all start out skeptics and that attempts to explain USB audio on a technical level are a waste of time. Trust me I have read many discussions like this and they go absolutely nowhere.

 

So if you want to find out if the Nordost Heimdall 2 usb makes a difference I strongly recommend trying one in your system, presuming this is something you want to find out and that your system is transparent enough to show a difference. If you purely want to discuss technical aspects of usb audio my humble suggestion is to find a thread better suited to that discussion, but I warn that will be a waste of time.

[gmgraves]

That's cool but this is getting way off topic. This thread is for discussing the Nordost Heimdall 2 not whether or not we are skeptical about USB cables having an audible difference. My 2 cents is we all start out skeptics and that attempts to explain USB audio on a technical level are a waste of time. Trust me I have read many discussions like this and they go absolutely nowhere.

 

So if you want to find out if the Nordost Heimdall 2 usb makes a difference I strongly recommend trying one in your system, presuming this is something you want to find out and that your system is transparent enough to show a difference. If you purely want to discuss technical aspects of usb audio my humble suggestion is to find a thread better suited to that discussion, but I warn that will be a waste of time.

 

 

Yes you are right, this discussion should end. I only got into it because I wanted somebody to explain to me how USB cable "break-in" could possibly occur. I didn't mean to start a debate about whether or not the perceived effects of USB cables or the break-in procedure had any value. As for trying a Nordost Heimdall 2, I'm not about to spend over $200 on a product whose performance can be duplicated (in my opinion) by a USB cable from MyCableMart for less than $10. I will, of course, reconsider my position, if somebody is able to prove, scientifically, that USB cables CAN and DO make a difference to the data that represents music in an audio system.

 

Thanks for your input.

[Starre]

George, so you say it can be duplicated for 10$ without even trying? That is a very strange way to get answers.

The main thing seems to be the cost for you, so you should write "the cost is too high anyway so I wont bother to try", that makes more sense to me.

[bdiament]

I agree. But...

 

Hi George,

 

That's exactly where you lose me.

Everything from there on is at odds with the first two words.

 

I said it in my previous post.

Let us agree to disagree.

 

Best regards,

Barry

Soundkeeper Recordings

The Soundkeeper | Audio, Music, Recording, Playback

Barry Diament Audio

[gmgraves]

George, so you say it can be duplicated for 10$ without even trying? That is a very strange way to get answers.

The main thing seems to be the cost for you, so you should write "the cost is too high anyway so I wont bother to try", that makes more sense to me.

 

I don't mind spending the money on something that I know will will result in a real result. But since there can be no sonic differences between USB cables and since certainly "burning-in" a USB cable will have no effect (unless one had two identical cables, one which is burned-in and one which is not - to compare directly, no one would be able to tell if burning-in the cable did anything or not. Nobody has that good of an aural memory. That has been proved many times, starting with Bell Labs back in the 1930s and is well known), in my opinion, there is simply no reason to spend 20 times the price of a MyCableMart USB cable for a pretty placebo.

[gmgraves]

Hi George,

 

That's exactly where you lose me.

Everything from there on is at odds with the first two words.

 

I said it in my previous post.

Let us agree to disagree.

 

Best regards,

Barry

Soundkeeper Recordings

The Soundkeeper | Audio, Music, Recording, Playback

Barry Diament Audio

 

 

I agree that "The search for understanding is admirable for sure..."

[kennyb123]

I agree that "The search for understanding is admirable for sure..."

 

I think there's two parts to it:

 

1) is there enough information out there such one can reach an understanding?

2) is that person willing and able to arrive at an understanding using that information?

 

It seems to me that there some in this hobby who are so heavily invested in the idea that USB cables can't make a difference that they are unwilling to accept any information that might cause them to change their position.

 

As such, I'd choose a slightly different wording than Bruce: "an intellectually-honest search for understanding is admirable for sure".

[bdiament]

Bruce?

 

What I was really driving at is two things that come to mind quite often when visiting Internet audio fora:

1. The assumption that even the slightest understanding is required in order for something to exist is not, in my opinion, a logical assumption. (If you don't understand internal combustion, you're only imagining that you're in a car.)

2. It has been my experience that when someone feels they can't learn anything new, they tend to be correct. ;-}

 

Best regards,

Barry

Soundkeeper Recordings

The Soundkeeper | Audio, Music, Recording, Playback

Barry Diament Audio

[kennyb123]

Bruce?

 

Sorry about taking your quote out of context.

 

What I was really driving at is two things that come to mind quite often when visiting Internet audio fora:

1. The assumption that even the slightest understanding is required in order for something to exist is not, in my opinion, a logical assumption. (If you don't understand internal combustion, you're only imagining that you're in a car.)

 

Yes, I've seen that too, but I have tended to consider it a red herring. Individuals who suggest this often seem to be just trying to appear as though they are looking for an explanation when in fact their minds are already made up. There's no new understanding that change their minds, but instead of acknowledging their bias, they just claim that they're still searching for "the" explanation.

 

2. It has been my experience that when someone feels they can't learn anything new, they tend to be correct.

 

Amen to that!

[gmgraves]

I think there's two parts to it:

 

1) is there enough information out there such one can reach an understanding?

2) is that person willing and able to arrive at an understanding using that information?

 

It seems to me that there some in this hobby who are so heavily invested in the idea that USB cables can't make a difference that they are unwilling to accept any information that might cause them to change their position.

 

As such, I'd choose a slightly different wording than Bruce: "an intellectually-honest search for understanding is admirable for sure".

 

While I know that there are many here who understand digital quantization of audio very well at a nuts-and-bolts level, I also get the impression that many more don't understand it very well, or at all. If one understands it at all, one realizes that nothing short of missing bits or large amounts of jitter (even that is suspect) can change a data file, and those are things that a cable simply can't do over a length of 5 meters or less (the limit for USB). That being the case, something else must be a work here. Nobody seems to have a clue as to what that "something" could possibly be, so that leaves only two things that make any sense at all, Voodoo (magic, the wrath of the gods, the alignment of the stars, etc.) or that most human of all variables, one's imagination.

[gmgraves]

Sorry about taking your quote out of context.

 

 

 

Yes, I've seen that too, but I have tended to consider it a red herring. Individuals who suggest this often seem to be just trying to appear as though they are looking for an explanation when in fact their minds are already made up. There's no new understanding that change their minds, but instead of acknowledging their bias, they just claim that they're still searching for "the" explanation.

 

 

 

Amen to that!

 

 

Well, that's certainly not me. I'd love to know what's going on here. Right now, it looks as if this USB cable thing (especially the burn-in part) is someone's imagination. If it's not, and that's certainly possible, then there is something that we don't know about digital sound and there is a fundamental flaw in digital quantization theory. If a digital cable can fundamentally change data representing music in a way that a DAC can interpret it as a different set of values for a sample, then none of our data can be trusted to arrive intact over USB and possibly over the internet either. I would think that if this were the case, we would have heard about it long before now, and a search would be under way at companies large and small, not to mention government research labs like Sandia National Laboratories or Universities like Stanford or MIT for an answer and a solution. Please keep in mind that I'm only pointing out that if you look at digital audio from an engineering perspective, it's only audio after it is parsed by a digital-to-analog-converter. Before that conversion it is no different from any other data that gets transferred over USB, pictures from a digital camera, movies from a camcorder, one's tax return (or the program that prepared it) etc. Like those types of data, only if the wrong data is transferred would anybody experience an application not working, a spreadsheet with the wrong values in it, a picture with pixels missing or transposed, and so on. If any of these things happened, you can bet your bottom dollar that somebody, somewhere, would be on this problem looking for a cause and a solution. Since no-one except certain audiophiles have ever mentioned a problem like this (to my knowledge), you have to admit that their observations must be viewed as suspicious. After all, if it can't be, it generally isn't, right?

[mayhem13]

Bruce?

 

What I was really driving at is two things that come to mind quite often when visiting Internet audio fora:

1. The assumption that even the slightest understanding is required in order for something to exist is not, in my opinion, a logical assumption. (If you don't understand internal combustion, you're only imagining that you're in a car.)

2. It has been my experience that when someone feels they can't learn anything new, they tend to be correct. ;-}

 

Best regards,

Barry

Soundkeeper Recordings

The Soundkeeper | Audio, Music, Recording, Playback

Barry Diament Audio

 

Always room for a well hidden insult within internet fora!

 

Not much else to say about this topic or your experiences except to highlight your own presumptions which seem to suit your experiences.....but others aren't as entitled?

Interesting perspective.

[kennyb123]

Well, that's certainly not me. I'd love to know what's going on here. Right now, it looks as if this USB cable thing (especially the burn-in part) is someone's imagination.

 

Oh no, it's certainly not you. No evidence here that you've made up your mind.

[The Computer Audiophile]

Stay on topic. If you don't like the topic just move on. If you feel an uncontrollable urge to comment for longer than four hours see a doctor.

[elcorso]

Stay on topic. If you don't like the topic just move on. If you feel an uncontrollable urge to comment for longer than four hours see a doctor.

 

But we have a doctor here!....

 

Where is Audio Doctor?

 

Best,

 

Roch

[gmgraves]

Oh no, it's certainly not you. No evidence here that you've made up your mind.

 

 

The difference between me and someone who has "made up their mind" is that the type of person that you are accusing me of being, will never change their mind no matter what evidence comes to light. For me, the conclusion that USB can't possibly change the sound of a digital audio signal is a conditional one; a working hypothesis, if you will. If somebody can prove some mechanism that would allow a cable to change the coding of a digital audio signal enough to make it sound different (while not affecting other types of data at all), then I will go out and buy a Nordost Heindall 2!

[JohnSwenson]

The difference between me and someone who has "made up their mind" is that the type of person that you are accusing me of being, will never change their mind no matter what evidence comes to light. For me, the conclusion that USB can't possibly change the sound of a digital audio signal is a conditional one; a working hypothesis, if you will. If somebody can prove some mechanism that would allow a cable to change the coding of a digital audio signal enough to make it sound different (while not affecting other types of data at all), then I will go out and buy a Nordost Heindall 2!

 

Hi George,

I'm going to try and take on this challenge, I have some qualifications on this, during the day I am a chip designer, I have worked on many USB chips, I know how they work and how they interact with their environment. By night I am a DAC designer who works with USB interfaces and how they work with their environment. I hope I can add a little bit of insight into this.

 

First off, USB is not one signaling standard, there are currently 3 in use, the one in use for a large percentage of DACs at the moment is the high speed standard, so I will cover just that.

 

HS mode runs at 480 Mbs, at this speed over normal human cable runs(measured in meters not mm) the "signal integrity" (SI) at the receiver can vary GREATLY. The spec allows for a very wide range of SI at the receiver, this means the receiver circuit has to be good enough to recover the data over this wide range of SI.

 

This receiver is NOT just a simple logic gate input. It uses a multiphase clock at 480MHz, some use 8, some 9 and the ones I worked with use 12 phases. This means there are twelve clocks, each at 480MHz, but slight delays between clocks. These different phases are generated by digitally controlled delay lines with 1/2ps resolution, you read that right, one half pico second resolution. Each of these clocks controls a very fast ADC with a few bits resolution. Thus every "bit" on the incoming analog signal is sampled 12 times, the digital representation of these analog values go into some DSP circuitry that tries and figure out where the "edge" actually is amongst all the noise, jitter and reflections on the wire.

 

If the SI is pretty good this determination is pretty easy, if the SI is not good, it has to work harder to figure out where the edge is. Part of this process is continuously tweaking the frequency of the clocks AND adjusting the exact delays of each of those phases to get the best data to the DSP block. Even though the clocks are 480MHz, the rate at which the frequency and delays are adjusted is right in the middle of the audio range. The worse the SI the more tweaking goes on.

 

Lest someone thinks this is USB only, this sort of thing is the basis for ALL high speed serial interfaces. USB HS is actually the simplest because it has to be dirt cheap, others do even more complex feedback on the input parameters. You really don't want to know what goes on in a thunderbolt receiver!

 

All of this processing to track the input signal generates lots of noise on the power traces and ground plane of a board. Even with very careful circuits and board layout some of this gets through to the DAC chip and its clock, which CAN change the output signal. Note: none of this actually changes the bits, that input circuit IS good enough to recover the actual bits. It is the consequences of the heroic measures taken by the receiver to get those bits in the face of poor SI that can affect the sound.

 

Measuring this stuff is not easy, frequencies are high and amplitudes are low. I don't have anywhere NEAR good enough test equipment at home to do this justice (we are talking about at least $50K, I can't afford that!!) and if I tried to use the stuff at work, I wouldn't be working, so a book full of graphs proving all this is not going to be coming from me anytime soon.

 

Gordon just got some equipment that CAN show this so sometime in the future you might be seeing some data from him.

 

I hope this helps a little bit in understanding how a USB cable may change the sound of a DAC.

 

John S.

[wwaldmanfan]

I have actually tried different USB cables on my system, ranging in price from a $10 printer cable to modestly priced audiophile cables ($50-$200). The differences are so profound that I think anyone who says they all sound the same is either deaf or hasn't actually compared them, and is talking out of their a**. It wouldn't surprise me if the premium USB cables that I can't afford sound even better.

[gmgraves]

George, so you say it can be duplicated for 10$ without even trying? That is a very strange way to get answers.

The main thing seems to be the cost for you, so you should write "the cost is too high anyway so I wont bother to try", that makes more sense to me.

 

Let me answer that by asking you a question Do you actually need to go up on the roof, jump off, and flap your naked arms wildly to know that you aren't going to fly? Of course not. You intrinsically know that you can't fly. The physics of flight tell you that gravity will pull you to the ground and that your arms can provide no lift, irrespective of how hard you flap them.

 

It is the same with USB cables. Since digital audio is just data, a cable cannot change the sound without altering the data. Since we know that isn't occurring (or it would have been observed by someone long before now), then the physics of digital quantization tells us that a USB cable cannot alter the sound. Just because you think you hear it, doesn't mean that it is so. How do I know this? Because I think that I have heard it too. But I'm more than certain that it has to be my imagination, because USB cables can't change the data. If they could and did, then USB would be useless as a computer interface.

[jwr]

Hi George,

I'm going to try and take on this challenge, I have some qualifications on this, during the day I am a chip designer, I have worked on many USB chips, I know how they work and how they interact with their environment. By night I am a DAC designer who works with USB interfaces and how they work with their environment. I hope I can add a little bit of insight into this.

 

First off, USB is not one signaling standard, there are currently 3 in use, the one in use for a large percentage of DACs at the moment is the high speed standard, so I will cover just that.

 

HS mode runs at 480 Mbs, at this speed over normal human cable runs(measured in meters not mm) the "signal integrity" (SI) at the receiver can vary GREATLY. The spec allows for a very wide range of SI at the receiver, this means the receiver circuit has to be good enough to recover the data over this wide range of SI.

 

This receiver is NOT just a simple logic gate input. It uses a multiphase clock at 480MHz, some use 8, some 9 and the ones I worked with use 12 phases. This means there are twelve clocks, each at 480MHz, but slight delays between clocks. These different phases are generated by digitally controlled delay lines with 1/2ps resolution, you read that right, one half pico second resolution. Each of these clocks controls a very fast ADC with a few bits resolution. Thus every "bit" on the incoming analog signal is sampled 12 times, the digital representation of these analog values go into some DSP circuitry that tries and figure out where the "edge" actually is amongst all the noise, jitter and reflections on the wire.

 

If the SI is pretty good this determination is pretty easy, if the SI is not good, it has to work harder to figure out where the edge is. Part of this process is continuously tweaking the frequency of the clocks AND adjusting the exact delays of each of those phases to get the best data to the DSP block. Even though the clocks are 480MHz, the rate at which the frequency and delays are adjusted is right in the middle of the audio range. The worse the SI the more tweaking goes on.

 

Lest someone thinks this is USB only, this sort of thing is the basis for ALL high speed serial interfaces. USB HS is actually the simplest because it has to be dirt cheap, others do even more complex feedback on the input parameters. You really don't want to know what goes on in a thunderbolt receiver!

 

All of this processing to track the input signal generates lots of noise on the power traces and ground plane of a board. Even with very careful circuits and board layout some of this gets through to the DAC chip and its clock, which CAN change the output signal. Note: none of this actually changes the bits, that input circuit IS good enough to recover the actual bits. It is the consequences of the heroic measures taken by the receiver to get those bits in the face of poor SI that can affect the sound.

 

Measuring this stuff is not easy, frequencies are high and amplitudes are low. I don't have anywhere NEAR good enough test equipment at home to do this justice (we are talking about at least $50K, I can't afford that!!) and if I tried to use the stuff at work, I wouldn't be working, so a book full of graphs proving all this is not going to be coming from me anytime soon.

 

Gordon just got some equipment that CAN show this so sometime in the future you might be seeing some data from him.

 

I hope this helps a little bit in understanding how a USB cable may change the sound of a DAC.

 

John S.

 

Thank you, thank you, thank you!

[Paul R]

Let me answer that by asking you a question Do you actually need to go up on the roof, jump off, and flap your naked arms wildly to know that you aren't going to fly? Of course not. You intrinsically know that you can't fly. The physics of flight tell you that gravity will pull you to the ground and that your arms can provide no lift, irrespective of how hard you flap them.

 

It is the same with USB cables. Since digital audio is just data, a cable cannot change the sound without altering the data. Since we know that isn't occurring (or it would have been observed by someone long before now), then the physics of digital quantization tells us that a USB cable cannot alter the sound. Just because you think you hear it, doesn't mean that it is so. How do I know this? Because I think that I have heard it too. But I'm more than certain that it has to be my imagination, because USB cables can't change the data. If they could and did, then USB would be useless as a computer interface.

 

 

Actually, I believe you need a cliff or two...

 

A Superman Flying in Norway, TRUE HUMAN FLIGHT in wingsuit! , wingsuit, Bispen, Norway - YouTube

[gmgraves]

Hi George,

I'm going to try and take on this challenge, I have some qualifications on this, during the day I am a chip designer, I have worked on many USB chips, I know how they work and how they interact with their environment. By night I am a DAC designer who works with USB interfaces and how they work with their environment. I hope I can add a little bit of insight into this.

 

First off, USB is not one signaling standard, there are currently 3 in use, the one in use for a large percentage of DACs at the moment is the high speed standard, so I will cover just that.

 

HS mode runs at 480 Mbs, at this speed over normal human cable runs(measured in meters not mm) the "signal integrity" (SI) at the receiver can vary GREATLY. The spec allows for a very wide range of SI at the receiver, this means the receiver circuit has to be good enough to recover the data over this wide range of SI.

 

This receiver is NOT just a simple logic gate input. It uses a multiphase clock at 480MHz, some use 8, some 9 and the ones I worked with use 12 phases. This means there are twelve clocks, each at 480MHz, but slight delays between clocks. These different phases are generated by digitally controlled delay lines with 1/2ps resolution, you read that right, one half pico second resolution. Each of these clocks controls a very fast ADC with a few bits resolution. Thus every "bit" on the incoming analog signal is sampled 12 times, the digital representation of these analog values go into some DSP circuitry that tries and figure out where the "edge" actually is amongst all the noise, jitter and reflections on the wire.

 

If the SI is pretty good this determination is pretty easy, if the SI is not good, it has to work harder to figure out where the edge is. Part of this process is continuously tweaking the frequency of the clocks AND adjusting the exact delays of each of those phases to get the best data to the DSP block. Even though the clocks are 480MHz, the rate at which the frequency and delays are adjusted is right in the middle of the audio range. The worse the SI the more tweaking goes on.

 

Lest someone thinks this is USB only, this sort of thing is the basis for ALL high speed serial interfaces. USB HS is actually the simplest because it has to be dirt cheap, others do even more complex feedback on the input parameters. You really don't want to know what goes on in a thunderbolt receiver!

 

All of this processing to track the input signal generates lots of noise on the power traces and ground plane of a board. Even with very careful circuits and board layout some of this gets through to the DAC chip and its clock, which CAN change the output signal. Note: none of this actually changes the bits, that input circuit IS good enough to recover the actual bits. It is the consequences of the heroic measures taken by the receiver to get those bits in the face of poor SI that can affect the sound.

 

Measuring this stuff is not easy, frequencies are high and amplitudes are low. I don't have anywhere NEAR good enough test equipment at home to do this justice (we are talking about at least $50K, I can't afford that!!) and if I tried to use the stuff at work, I wouldn't be working, so a book full of graphs proving all this is not going to be coming from me anytime soon.

 

Gordon just got some equipment that CAN show this so sometime in the future you might be seeing some data from him.

 

I hope this helps a little bit in understanding how a USB cable may change the sound of a DAC.

 

John S.

 

 

Thank you for that explanation, it is very enlightening. However you made one statement that has me wondering what you are actually saying here: "Note: none of this actually changes the bits, that input circuit IS good enough to recover the actual bits." Since the "bits" are all we really care about here (as they ARE the data) it seems to me that would put the question to rest. But then you go on to say: "It is the consequences of the heroic measures taken by the receiver to get those bits in the face of poor SI (signal integrity) that can affect the sound." Would you mind elaborating on that last statement please? If the data is recovered intact, then the DAC will reconstruct the audio waveform (to the limits of it's capability due to quantization error, and analog stage distortion and noise, that is) exactly as the data tells it to. Changing cables does not, as you point out, affect the USB receiver's ability to recover the actual bits intact, so why would the receiver's "heroic measures" change the sound if the bits are recovered as transmitted? I look forward to your response.

[gmgraves]

Actually, I believe you need a cliff or two...

 

A Superman Flying in Norway, TRUE HUMAN FLIGHT in wingsuit! , wingsuit, Bispen, Norway - YouTube

 

 

Yes Paul, I know about wingsuits. That's why I was careful to specify naked arms. I knew that were I not careful to make that distinction, that some contentious so-and-so would bring up wingsuits in order to prove my analogy wrong. Looks like my careful wording didn't do me much good in that instance.

[kennyb123]

Since the "bits" are all we really care about here (as they ARE the data) it seems to me that would put the question to rest.

 

No, what we care about is whether the output signal is effected. You seem to have skipped right over what might be the most important point that John made (bold text mine):

 

All of this processing to track the input signal generates lots of noise on the power traces and ground plane of a board. Even with very careful circuits and board layout some of this gets through to the DAC chip and its clock, which CAN change the output signal.