[BiggerHead]

I had a theory but I don't like it.    Anyway, there is an old technical term for exactly this effect.  It's called a "glitch".

 

[BiggerHead]

Ok, my original version of this theory stunk, but basically a poor ground connection might mess things up in unpredictable ways, maybe create reflections or cross talk.  I'd think you'd need to be on USB power/ground only for that to add up. For a bad enough ground connection you'd expect to loose power and signal, but you may have found a middle ground (ha ha ha!) had it put it back just to make everyone suffer that awesome pun.
 
So I'm just making this up but maybe something like this could happen, anyway see my previous post for the conclusion.

 

[castleofargh]

  Ok, my original version of this theory stunk, but basically a poor ground connection might mess things up in unpredictable ways, maybe create reflections or cross talk.  I'd think you'd need to be on USB power/ground only for that to add up. For a bad enough ground connection you'd expect to loose power and signal, but you may have found a middle ground (ha ha ha!) had it put it back just to make everyone suffer that awesome pun.
 
So I'm just making this up but maybe something like this could happen, anyway see my previous post for the conclusion.

well that's what I have always hated about USB, the plugs. but I guess not all devices would be fine with several big banana plugs instead of a USB plug ^_^.  
IDK how much of an impact that can have for USB, I've messed up many resistance and impedance measurements with poor contacts so I do believe in the value of plugs making good contacts for all signals, now

.

 

[serman005]

Never used a USB connector. I think I am going to give it a shot.

 

[coli]

If USB cable makes a difference, you need a better, properly implemented DAC by people who actually knows what they are doing. Chances are, it'll be a cheaper, mass market DAC.

 

[BiggerHead]

The important predicate was "If (and when) USB cables make a difference"

And the important conclusion would also be "then USB cables make a difference"

What one needs would depend on a balance of details in their situation.

But the topic was: Why USB cables CAN make a difference.

I think you're point is that you are concluding : If they can, it's only with lousy equipment. Fair enough, although I think we've seen lousy might not always mean cheap Walmart stuff, but you did make that point.

 

[castleofargh]

I've realized something a few years back also on a cable topic. when someone sees a reason for paying a good deal of money to get the "better sound", all I could see was a cable doing it's job well enough or not.  our starting points couldn't be more different.
 
to some, a basic cable would give basic sound. and a great cable would give great sound. it's kind of cute IMO but the cable has the proper specs(following a standard) or it doesn't. and if someone needs special exotic specs for his cable, then the situation itself is exotic. so by definition, the stuff shouldn't be sold as being better for all USB devices like audiophile band-aids and audiophile USB cables are. that would be like selling ski boots as high end shoes. they may be great for one situation, but they really suck for everything else. and I'm pretty confident that many USB solutions are just like that. helping one guy, degrading the sound of 5 others.
 
so in my mind when a system doesn't work as advertised with default cables, the device is crap. 
if the DAC needed a ferrite bead, then engineer guy, why doesn't the DAC already have one at the usb input? if it needed special impedance cable not at all standard, then they obviously should provide the damn cable and specify that something special is needed when we have to replace the cable. if some potential problem exists with EMI reaching the cable, then why the hell wouldn't they do something about it themselves? or at least suggest to the buyers from the start, to do X in case they notice Y? etc etc
however I turn this in my head, if we have to add something to get a DAC work as advertised, and another standard cable doesn't solve the issue(some cables are bogus, it happens), then it's the DAC's fault and I should just get rid of the mofo and get one that does what it claims to do.
 
 
so I really do not see things in any way like the guy getting the expensive cable or magic box does. from start to finish we look at different worlds.

 

[mmerrill99]

I've realized something a few years back also on a cable topic. when someone sees a reason for paying a good deal of money to get the "better sound", all I could see was a cable doing it's job well enough or not.  our starting points couldn't be more different.

to some, a basic cable would give basic sound. and a great cable would give great sound. it's kind of cute IMO but the cable has the proper specs(following a standard) or it doesn't. and if someone needs special exotic specs for his cable, then the situation itself is exotic. so by definition, the stuff shouldn't be sold as being better for all USB devices like audiophile band-aids and audiophile USB cables are. that would be like selling ski boots as high end shoes. they may be great for one situation, but they really suck for everything else. and I'm pretty confident that many USB solutions are just like that. helping one guy, degrading the sound of 5 others.

so in my mind when a system doesn't work as advertised with default cables, the device is crap. 
if the DAC needed a ferrite bead, then engineer guy, why doesn't the DAC already have one at the usb input? if it needed special impedance cable not at all standard, then they obviously should provide the damn cable and specify that something special is needed when we have to replace the cable. if some potential problem exists with EMI reaching the cable, then why the hell wouldn't they do something about it themselves? or at least suggest to the buyers from the start, to do X in case they notice Y? etc etc
however I turn this in my head, if we have to add something to get a DAC work as advertised, and another standard cable doesn't solve the issue(some cables are bogus, it happens), then it's the DAC's fault and I should just get rid of the mofo and get one that does what it claims to do.


so I really do not see things in any way like the guy getting the expensive cable or magic box does. from start to finish we look at different worlds.

I'm not defending expensive cables, just as I'm not defending expensive DACs or computers but expensive products exist in the capitalist system & individuals decide on the cost-benefit of what they purchase. It seems to me that marketing concerns are the constant theme in this section rather than the technological aspects which is disappointing in "sound section".

I believe your viewpoint also misses some very important aspects of the reality of manufacturing products. In any product manufacturing there are many limitations defined by the budget which means that unlimited testing is not within budget.

You are also misstating what USB cables are about when you say this "however I turn this in my head, if we have to add something to get a DAC work as advertised, and another standard cable doesn't solve the issue(some cables are bogus, it happens), then it's the DAC's fault and I should just get rid of the mofo and get one that does what it claims to do". What USB cables are being sold as is not making a broken DAC work but making an existing working DAC sound better. So, to some extent you are correct, the whole USB cable market shouldn't exist if USB audio devices were built to a standard that deals with these noise issues but there is no noise standard that applies to USB which considers the analogue side of USB DACs. One could nearly say that the USB cable market is providing a service to the audio industry by focussing attention on the aspects of computer audio that have been ignored & continue to be ignored. But this lesson will only get through to those who have a mind to learn.

Again, I'm not defending USB cable marketers - I would prefer if they did testing to evaluate just how their cables are benefitting the analogue side of audio but I suspect that this testing & measurement will be pretty difficult to do & will require some different approaches to the standard measurements.

But I really don't know what all the argument is about here - there's a simple test that one can do - use a USB isolator & if it improves the sound of a USB DAC, then according to many here you have a broken DAC - get rid of the mofo. Does this change in sound mean the DAC is "broken"? Of course not. Does it mean that the DAC is not fully optimised? Yes, of course. What selection criteria are you going to use to replace this mofo that you just got rid of?

Is the problem the DAC's lack of immunity to noise or is it the PC's noise emissions? Where does the problem lie - in the "dirty" PC or the "broken" DAC?

When you have found a USB DAC that isn't improved by a USB isolator or a PC (actually it's not just the PC but the whole playback chain that's critical) - please post the info here as it will be educational for many here

 

[ralphp@optonline]

I'm not defending expensive cables, just as I'm not defending expensive DACs or computers but expensive products exist in the capitalist system & individuals decide on the cost-benefit of what they purchase. It seems to me that marketing concerns are the constant theme in this section rather than the technological aspects which is disappointing in "sound section".

I believe your viewpoint also misses some very important aspects of the reality of manufacturing products. In any product manufacturing there are many limitations defined by the budget which means that unlimited testing is not within budget.

You are also misstating what USB cables are about when you say this "however I turn this in my head, if we have to add something to get a DAC work as advertised, and another standard cable doesn't solve the issue(some cables are bogus, it happens), then it's the DAC's fault and I should just get rid of the mofo and get one that does what it claims to do". What USB cables are being sold as is not making a broken DAC work but making an existing working DAC sound better. So, to some extent you are correct, the whole USB cable market shouldn't exist if USB audio devices were built to a standard that deals with these noise issues but there is no noise standard that applies to USB which considers the analogue side of USB DACs. One could nearly say that the USB cable market is providing a service to the audio industry by focussing attention on the aspects of computer audio that have been ignored & continue to be ignored. But this lesson will only get through to those who have a mind to learn.

Again, I'm not defending USB cable marketers - I would prefer if they did testing to evaluate just how their cables are benefitting the analogue side of audio but I suspect that this testing & measurement will be pretty difficult to do & will require some different approaches to the standard measurements.

But I really don't know what all the argument is about here - there's a simple test that one can do - use a USB isolator & if it improves the sound of a USB DAC, then according to many here you have a broken DAC - get rid of the mofo. Does this change in sound mean the DAC is "broken"? Of course not. Does it mean that the DAC is not fully optimised? Yes, of course. What selection criteria are you going to use to replace this mofo that you just got rid of?

Is the problem the DAC's lack of immunity to noise or is it the PC's noise emissions? Where does the problem lie - in the "dirty" PC or the "broken" DAC?

When you have found a USB DAC that isn't improved by a USB isolator or a PC (actually it's not just the PC but the whole playback chain that's critical) - please post the info here as it will be educational for many here

You pose some very interesting and well stated questions. Hopefully we can come with some plausible answers.
 
First there's measurements. So are we speaking about clearly audible changes in the sound or changes to something that can be measured but not heard?
 
If the first, then I would say just set a way to digitally record the output from a given set of headphones (hey this Head-Fi after all) and amps with USB cable A and then with USB cable B and run the files (recordings) through an audio difference analyzer program.
 
If the second then so what, so cable B reduces the noise/jitter/whatever that already could not hear. Great here's my money sir. Sir, may I have another Sir?
 
And finally get a better PC, one without a cheap power supply or perhaps it's one the other power supplies or wait maybe it's a bad ground loop.
 
All of your questions always bring us back around to the beginning, over and over again. Please tell us if and when this will ever end.

 

[mmerrill99]

I'm not defending expensive cables, just as I'm not defending expensive DACs or computers but expensive products exist in the capitalist system

You pose some very interesting and well stated questions. Hopefully we can come with some plausible answers.

Thanks & look forward to the plausible answers.

First there's measurements. So are we speaking about clearly audible changes in the sound or changes to something that can be measured but not heard?

If the first, then I would say just set a way to digitally record the output from a given set of headphones (hey this Head-Fi after all) and amps with USB cable A and then with USB cable B and run the files (recordings) through an audio difference analyzer program.

If the second then so what, so cable B reduces the noise/jitter/whatever that already could not hear. Great here's my money sir. Sir, may I have another Sir?

And finally get a better PC, one without a cheap power supply or perhaps it's one the other power supplies or wait maybe it's a bad ground loop.

All of your questions always bring us back around to the beginning, over and over again. Please tell us if and when this will ever end.

I'm not sure where you think the beginning is or where the plausible answers are?

I know that anything I post will be rejected by you, out of hand so I don't expect to sway you one iota. Don't take the following text as referring to you or as suggestions to you, personally - these are really addressed to any moderate readers of this thread

Here's what I suggest - it's something I suggested already & cuts through all of the above - someone gets an Intona USB isolator, listens & measures it. It's not a snakeoil product, so we are establishing some firm reference point from which to continue.

What has this got to do with USB cables? Well I'm suggesting is to start with a USB product which has an understandable & measurable effect on the analogue out - listen to it & measure it. I already showed some published measurement of a DAC's analogue out before/after insertion of the Intona in the USB line. What this didn't have was a before/after listening report. Just to refresh the memory here are the before/after measurements again

After:


So we see two types of changes in the measurements of the audible frequency range (1)a drop in overall noise floor ranging from about 30dB drop at LF to about 10dB drop at HF (2)Some harmonics & other noise spikes reduced - a second harmonic reduced from -95dB to -115dB & 8KHz & 16KHz noise spikes reduced from -85dB to below the noise floor

Now, would you think these measureable changes make an audible improvement/difference in the sound heard?

I suggest someone gets an Intona & judges it's audible effect on their system. If not audible you have one of two possible scenarios: One, you have an exemplary playback system without any noise bleed issues. Or, two, you have a playback system that masks the audible difference from the removal of such noise.

If it does make an audible change then do the measurements on the DAC's analogue output & show the correlation to this audible change.

If this is done then I predict a great deal of enlightenment would result.

Then one can consider the more difficult problem of measuring any subtle changes on the DAC analogue out using a USB cable & what measuring it might entail

 

[spruce music]

Thanks & look forward to the plausible answers.
I'm not sure where you think the beginning is or where the plausible answers are?

I know that anything I post will be rejected by you, out of hand so I don't expect to sway you one iota. Don't take what the following text as referring to you or as suggestions to you, personally - these are really addressed to any moderate readers of this thread

Here's what I suggest - it's something I suggested already & cuts through all of the above - someone gets an Intona USB isolator, listens & measures it. It's not a snakeoil product, so we are establishing some firm reference point from which to continue.

What has this got to do with USB cables? Well I'm suggesting to start with a USB product which has an understandable & measurable effect on the analogue out. I already showed some published measurement of a DAC's analogue out before/after insertion of the Intona in the USB line. What this didn't have was a before/after listening report. Just to refresh the memory here are the before/after measurements again

After:


So we see two types of changes in the measurements of the audible frequency range (1)a drop in overall noise floor ranging from about 30dB drop at LF to about 10dB drop at HF (2)Some harmonics & other noise spikes reduced - a second harmonic reduced from -95dB to -115dB & 8KHz & 16KHz noise spikes reduced from -85dB to below the noise floor

Now, would you think these measureable changes make an audible improvement/difference in the sound heard?

I suggest someone gets an Intona & judges it's audible effect on their system. If not audible you have one of two possible scenarios: One, you have an exemplary playback system without any noise bleed through issues. Or, two, you have a playback system that masks the audible difference from the removal of such noise.

If it does make an audible change then do the measurements on the DAC's analogue output & show the correlation to this audible change.

If this is done then I predict a great deal of enlightenment would result.

Then one might consider the more difficult problem of measuring any changes on the DAC analogue out using a USB cable & what it might entail

So what were the AD and DA in use?  I am not sure the difference is audible though I am not sure it isn't.  I would lean toward saying those two cases would be audible as different. That is a possibility you left out.  It makes this measurable difference and yet you don't hear it as the distortion and noise was already inaudible in the before Intona case. 
 
What is the source of these measurements? They would point to the Intona making a great improvement that other devices like the Regen fail to make.  Of course the first measurement is of a DA with rather poor noise levels.  That looks to be something like a 75 db noise floor.  Like you might find in a PC soundcard.  The 8 khz USB bleedthrough is also worse than is normally seen with good DA gear. 

 

[mmerrill99]

So what were the AD and DA in use?  I am not sure the difference is audible though I am not sure it isn't.  I would lean toward saying those two cases would be audible as different. That is a possibility you left out.

I suspect the A/D & D/A were from RME as that's the source of the measurements seen on the bottom of the page "Courtesy of Matthias Carstens, RME" 

It makes this measurable difference and yet you don't hear it as the distortion and noise was already inaudible in the before Intona case.

OK, that's why I suggested that one should acquire/borrow an Intona & listen - then take measurements. In my experience, the Intona makes an audible difference in all playback chains I have heard it used in. 

What is the source of these measurements? They would point to the Intona making a great improvement that other devices like the Regen fail to make.  Of course the first measurement is of a DA with rather poor noise levels.  That looks to be something like a 75 db noise floor.  Like you might find in a PC soundcard.  The 8 khz USB bleedthrough is also worse than is normally seen with good DA gear. 

Well RME don't make "broken" digital audio gear, AFAIK but that's probably a matter of (mis)-interpretation, I guess I'm pretty sure that poor noise floor is the result of ground loop rather than a DA with inherently poor noise?

 

[ralphp@optonline]

Thanks & look forward to the plausible answers.
I'm not sure where you think the beginning is or where the plausible answers are?

I know that anything I post will be rejected by you, out of hand so I don't expect to sway you one iota. Don't take the following text as referring to you or as suggestions to you, personally - these are really addressed to any moderate readers of this thread

Here's what I suggest - it's something I suggested already & cuts through all of the above - someone gets an Intona USB isolator, listens & measures it. It's not a snakeoil product, so we are establishing some firm reference point from which to continue.

What has this got to do with USB cables? Well I'm suggesting is to start with a USB product which has an understandable & measurable effect on the analogue out - listen to it & measure it. I already showed some published measurement of a DAC's analogue out before/after insertion of the Intona in the USB line. What this didn't have was a before/after listening report. Just to refresh the memory here are the before/after measurements again

After:


So we see two types of changes in the measurements of the audible frequency range (1)a drop in overall noise floor ranging from about 30dB drop at LF to about 10dB drop at HF (2)Some harmonics & other noise spikes reduced - a second harmonic reduced from -95dB to -115dB & 8KHz & 16KHz noise spikes reduced from -85dB to below the noise floor

Now, would you think these measureable changes make an audible improvement/difference in the sound heard?

I suggest someone gets an Intona & judges it's audible effect on their system. If not audible you have one of two possible scenarios: One, you have an exemplary playback system without any noise bleed issues. Or, two, you have a playback system that masks the audible difference from the removal of such noise.

If it does make an audible change then do the measurements on the DAC's analogue output & show the correlation to this audible change.

If this is done then I predict a great deal of enlightenment would result.

Then one can consider the more difficult problem of measuring any subtle changes on the DAC analogue out using a USB cable & what measuring it might entail

 
 

 
So what were the AD and DA in use?  I am not sure the difference is audible though I am not sure it isn't.  I would lean toward saying those two cases would be audible as different. That is a possibility you left out.  It makes this measurable difference and yet you don't hear it as the distortion and noise was already inaudible in the before Intona case. 
 
What is the source of these measurements? They would point to the Intona making a great improvement that other devices like the Regen fail to make.  Of course the first measurement is of a DA with rather poor noise levels.  That looks to be something like a 75 db noise floor.  Like you might find in a PC soundcard.  The 8 khz USB bleedthrough is also worse than is normally seen with good DA gear. 

 
 

I suspect the A/D & D/A were from RME as that's the source of the measurements seen on the bottom of the page "Courtesy of Matthias Carstens, RME" 
OK, that's why I suggested that one should acquire/borrow an Intona & listen - then take measurements. In my experience, the Intona makes an audible difference in all playback chains I have heard it used in. 
Well RME don't make "broken" digital audio gear, AFAIK but that's probably a matter of (mis)-interpretation, I guess

I'm pretty sure that poor noise floor is the result of ground loop rather than an inherent DA with poor noise?

Here we go 'round in circles.
 
I do apologize for waking the sleeping dog.

 

[castleofargh]

I'm not defending expensive cables, just as I'm not defending expensive DACs or computers but expensive products exist in the capitalist system & individuals decide on the cost-benefit of what they purchase. It seems to me that marketing concerns are the constant theme in this section rather than the technological aspects which is disappointing in "sound section".

 

 as an objective ghetto, of course we will be skeptical by nature. I really don't see how that is a bad thing. I like objective stuff with objective evidence. everything else looks to me like empty claims and marketing. it may be real, but without evidence, why should I even care?
-"hello I'm castleofargh and I'm an objectivist".

 
 

I believe your viewpoint also misses some very important aspects of the reality of manufacturing products. In any product manufacturing there are many limitations defined by the budget which means that unlimited testing is not within budget.

.....

Again, I'm not defending USB cable marketers - I would prefer if they did testing to evaluate just how their cables are benefitting the analogue side of audio but I suspect that this testing & measurement will be pretty difficult to do & will require some different approaches to the standard measurements.

of course, but wouldn't you expect problems from this to be atypical and limited to a few devices using the same flawed design or components? and if so, a solution if it could be implemented in a cable would be specific to those devices, not sold as some universal miracle remedy said to improve unquantifiable mind constructs like soundstage or whatever.
and once found out, why the hell would manufacturer still keep doing the same mistake on the new model?
I have no doubt that corners are cut, because of time, because of money, because they have no budget for actual beta testing in a lot of conditions. but am I to understand that within the entire industry, they almost all failed to notice something, and that a cable manufacturer who doesn't even have the means to make proper measurements, will have come up with an improvement?
are we talking reality or fairy tales here?
 
 
 

But I really don't know what all the argument is about here - there's a simple test that one can do - use a USB isolator & if it improves the sound of a USB DAC, then according to many here you have a broken DAC - get rid of the mofo. Does this change in sound mean the DAC is "broken"? Of course not. Does it mean that the DAC is not fully optimised? Yes, of course. What selection criteria are you going to use to replace this mofo that you just got rid of?

Is the problem the DAC's lack of immunity to noise or is it the PC's noise emissions? Where does the problem lie - in the "dirty" PC or the "broken" DAC?

When you have found a USB DAC that isn't improved by a USB isolator or a PC (actually it's not just the PC but the whole playback chain that's critical) - please post the info here as it will be educational for many here

I really don't see how that would bring anything up. you want to know if a cable does something you measure the cable, you don't go looking for a magic box, see what it does and then expect to conclude that a cable matters.
it's easy enough to RMAA and record stuff with 2 cables and then use audio diffmaker or whatever. even if we don't have the tools to measure jitter down -120db, it's easy to at least check if a cable will change things within the resolution of the ADC. then and only then care to look for the reasons for such differences.
but trying to justify the importance of a cable when we don't even have evidence that they make significant changes, it's not very rational IMO.
and how I would replace what I call defective, if it's noise I would look for specs about that, or simply look around for DAC that don't seem to ever have such problem. if it's something else, well unless it's measurable, I honestly doubt I would even be aware of it ^_^.
 
 
for all I know sometime the USB slots on the motherboard will suck(plenty of noise, ground stuff ...), can a cable help? IDK. I've been told many times to just add a USB card and use it when problems occur.
I've been told not to stack too many high traffic devices on the same hub or card. I haven't personally witnessed this to be a problem, but I don't listen to highres or stuff like that. for that I doubt that a cable would help anyway.
we know of problems with noise, usually a ferrite bead is a pretty cheap helper added close to the DAC. again I don't happen to have any noise problem with the stuff I now own, so I can't really hope to test, because my ADC has more noise than my DAC. but if it's generally a good idea, why don't the manufacturers add the damn ferrite bead at the USB input like I asked before? are they stupid? or maybe there is a drawback to doing that? if so the ferrite isn't such a universal improvement anymore. and I suspect it's like that for everything, like galvanized isolation. if any of those stuff was a magical answer, it would be implemented in all devices. or are we really supposed to expect designers to be cheap idiots?
we know about the 5V not being 5V, that certainly can be a massive issue, but will a cable help?
 
I put USB cables, like any other cables at the very end of what matters in audio. not because I enjoy making super not so audacious statements, but because I haven't seen evidence that I should care about cables in general. as always you can decide that it's narrow minded not to stay open to the possibility, but I'm always open to changing my mind should objective evidence lead me to believe that I should pay more attentions to my USB cable. until then I will use the cable that came with the DAC and worry about other stuff.

 

[spruce music]

I suspect the A/D & D/A were from RME as that's the source of the measurements seen on the bottom of the page "Courtesy of Matthias Carstens, RME" 
OK, that's why I suggested that one should acquire/borrow an Intona & listen - then take measurements. In my experience, the Intona makes an audible difference in all playback chains I have heard it used in. 
Well RME don't make "broken" digital audio gear, AFAIK but that's probably a matter of (mis)-interpretation, I guess

I'm pretty sure that poor noise floor is the result of ground loop rather than a DA with inherently poor noise?

Okay so now I see the rest of the story.  Intona claims to break ground loops and provide isolation.  And they do.  They also created a rather bad ground loop to show that.  Many/most good pieces of gear however are not suffering from that.  Or if they are it may be solvable through other means.  I have not in the few DACs I have measured seen one as poor as their before result except in computer sound cards.  So in a system with no grounding issues the before and after would for sure be a lesser difference, and may be no difference.
 
If your gear isn't suffering from this, it is a logical leap to find the Intona will provide improved sound.  The Intona appears to be a well designed unit doing exactly what it claims.  If you need it good.  I am not convinced it automatically will help your DAC sound better if such grounding/noise issues are not present. I don't think Intona would claim their unit is a panacea sure to improve sound in all cases.