KIMBER KABLE: Do High-end USB Cables Make A Difference?

[Gekel]

And while on this learning spree, I would also suggest you to look at the 'asynchronous data transfer'. Where - by using the 'buffering' concept - the data is delivered from 'storage' (eg, a computer) to 'consumer' (eg, an audio DAC device) over a non-perfect, jittery media

Leave this asynchronous data transfer aside and have a look at the data transfer protocol used to send audio information over an USB port using DSD. If you have at least some knowlegde in maths (keyword: fourier transformation) all it takes is to look up what pulse density modulation means, and then you can immediately rule out any of the claims about "more bass" "clearer hights" or "darker background" when people try to explain the difference in different usb cables.

 

[Gekel]

I forgot to add that delta-sigma modulation is required on top of that (shame on me).

In case anyone is interested: sound/music consists of multiple frequencies which overlap and form a more or less chaotic frequency wave. In the real world, this frequency mixture is transfered over the air by pushing/pulling the molecules of the air (you can feel this if you stand in front of a kicker bass blasting at a low frequency and making your hairs fly).

DSD now uses this idea of "air density" (or air flow, or air being pushed/pulled around) for data encoding into a bit stream. What DSD does is to send a constant stream of 0 and 1, with the encoding that a 1 pushes the virtual air into your direction (so to speak), while a 0 pulls it away from you. Here is a picture with the same data ( a sinus wave) encoded in two ways, one with the DSD data, the other the typical analog sinus wave.

If a cable or a power supply wants to enhance the sound quality ("more clear bass"), this 0 1 0 1 0 bit stream has first to be translated back into data which uses frequency/time as encoding and not a pulse/density, then change the balance of the different frequencies to enhance some sound ranges and last but not least use delta-sigma modulation to translate the information back into the stream the DAC is expecting. Or if you look at the linked picture: You first need to translate these 0 1 0 1 bit combination to get the sinus wave. Then you can play around with that wave, but to make your DAC happy you then need to translate this back into the 0 1 01 stream.

The same applies if you use a cheaper cable in the oposite direction, and that my friends is a bit too much intelligence for such a cable.

On top there is zero chance that any noisy frequency coming from the power supply or other source could modify this data stream (and switches exactly the 0 and 1 in the correct position of the data stream) in such a specific way to achieve any sound enhancement by accident, while bypassing the reqired transcodings The frequency used to generate such a bit stream is by magnitudes higher (2.8 MHz) than any frequency around (e.g. 220V supply with 50/60 Hz). All you can do is to erase the whole bit stream, and then the DAC stops acepting data. You can't use something which can change data from 0 to 1 or the other way around working at a frequency of 60 Hz to modify a data stream using 2.8 MHz.

Last but not least it's impossible to get a "darker, less noisy background". Silence in DSD language means a 1 0 1 0 1 0 1 0 bit stream (check the linked picture, look at the area where the sinus wave is near zero amplitude) and how the corresponding bit stream looks like. So any "thing" which wants to make such a stream less noisy needs to be able to identify the areas of the data stream where 0 and 1 need to be adjusted in a way to form a better 0 1 0 1 0 1 alternating data stream, and this stream pushes out at 2.8 MHz, so that thing needs to analyse and "enhance" 2.8 mio bits/sec. So what people think by applying rules of the analog world doesn't work in the DSD world. If you achieve to generate a low noise constant electrical signal (using an audiophile LSP instead of a noisy cheap power supply) this either results in a constant stream of 00000000 or 111111, which is exactly the opposite of what DSD uses to expresss silenece (01010101010101).

Over and out. Don't let this any audiophile crack see, becaus all that counts are 0 and 1

 

[Gekel]

Last sentence: forget about Jitter with DSD. You cannot modify the frequency of an analog signal encoded in a pulse density data stream by "jittering" around with the 0 and 1 of this data stream. That's not how it works.

 

[Raindog123]

Five stages of understanding:

Stage one: ‘One big scary shiit, don’t understand it at all!’
Stage two: ‘Starting to make sense!’
Stage three: ‘World! I understand it all!’
Stage four: ‘Shoot. Now I understand it. (What was I thinking!?)’
Stage five: ‘Wait, the guy next to me understands it too!?’

 

[Gekel]

Five stages of understanding:

Stage one: ‘One big scary shiit, don’t understand it at all!’
Stage two: ‘Starting to make sense!’
Stage three: ‘World! I understand it all!’
Stage four: ‘Shoot. Now I understand it. (What was I thinking!?)’
Stage five: ‘Wow, the guy next to me understands it too!’

So you understood my explanation of PDM/DSD, or do you mean I just stumbled across a long known explanation how the data transfer works but I just haven't found it (yet) in this page?

 

[WickedInsignia]

Thanks for the personal attack

Quite a few people have given you their time and attention here but it’s obvious that none of us are getting very far with someone that is being so selective about what they want to hear.
I really do not blame people for losing patience.

 

[THW]

ngl i mistook “Connaker” for “Conmaker”, lmao

 

[Chuckser]

what tests do you propose?

32 tone at least.

 

[Chuckser]

How would a cable "know" that it is a sine wave sequence of values and act differently? Is a cable trained to tell a sine wave from music?

BTW, this jitter test uses infinite harmonics of the main frequency, not one tone:

So your premise is not correct anyway.

Re-read my post, please.

 

[Andretti60]

Note that by this definition, EVERYTHING is ANALOG!

…

And that is exactly why USB cables DO sound different (disclaimer: you can hear the difference only if you use extremely high end DAC, see below).

Any cable used to transmit data DOES introduce errors, this is a very well known fact, this is why when we want to avoid data transfer errors we use a communication protocol with “error checking”, if the data that we receive is NOT correct, we just send back a request to resend the data. This works great and this is why for example we can transfer files other the internet with no errors. Now, real data streaming (like audio) cannot do that, there is just not enough time to request another packet (packet: a set of a fixed number of bytes that the receiver is able to recognize with a start and an end), therefore streaming data CAN indeed have errors.

So the right questions to ask: how many data transmission errors there are in a cheap basic Amazon USB cable vs a thousand dollar cable, how many errors are introduced by the EMF surrounding the cable, and if it is possible to effectively “hear” the difference at all. That, detective, is the right question (prof. Alfred Lanning).

And I can give you “my” very personal answer: with my ears and my audio equipment I cannot honestly hear ANY difference at all. The only reason I don’t buy cheap cables (both digital and analogue) is that their plastic breaks down in time. The cheap lighting cables that come with an iPhone don’t even last one year, especially because we use them on a daily base.

If you want to hear more you can watch the funny (but instructional) “Do USB Cables Make a Difference” video by the founder of PSAudio, Paul McGowan.

 

[dc655321]

And that is exactly why USB cables DO sound different (disclaimer: you can hear the difference only if you use extremely high end DAC, see below).

Any cable used to transmit data DOES introduce errors, this is a very well known fact, this is why when we want to avoid data transfer errors we use a communication protocol with “error checking”, if the data that we receive is NOT correct, we just send back a request to resend the data. This works great and this is why for example we can transfer files other the internet with no errors. Now, real data streaming (like audio) cannot do that, there is just not enough time to request another packet (packet: a set of a fixed number of bytes that the receiver is able to recognize with a start and an end), therefore streaming data CAN indeed have errors.

So the right questions to ask: how many data transmission errors there are in a cheap basic Amazon USB cable vs a thousand dollar cable, how many errors are introduced by the EMF surrounding the cable, and if it is possible to effectively “hear” the difference at all. That, detective, is the right question (prof. Alfred Lanning).

And I can give you “my” very personal answer: with my ears and my audio equipment I cannot honestly hear ANY difference at all. The only reason I don’t buy cheap cables (both digital and analogue) is that their plastic breaks down in time. The cheap lighting cables that come with an iPhone don’t even last one year, especially because we use them on a daily base.

If you want to hear more you can watch the funny (but instructional) “Do USB Cables Make a Difference” video by the founder of PSAudio, Paul McGowan.

What would the flipping of a few random bits in a digital music signal sound like when rendered in the analog domain?

What do you imagine bit errors sound like?

 

[Frank Dernie]

And that is exactly why USB cables DO sound different (disclaimer: you can hear the difference only if you use extremely high end DAC, see below).

Any cable used to transmit data DOES introduce errors, this is a very well known fact, this is why when we want to avoid data transfer errors we use a communication protocol with “error checking”, if the data that we receive is NOT correct, we just send back a request to resend the data. This works great and this is why for example we can transfer files other the internet with no errors. Now, real data streaming (like audio) cannot do that, there is just not enough time to request another packet (packet: a set of a fixed number of bytes that the receiver is able to recognize with a start and an end), therefore streaming data CAN indeed have errors.

So the right questions to ask: how many data transmission errors there are in a cheap basic Amazon USB cable vs a thousand dollar cable, how many errors are introduced by the EMF surrounding the cable, and if it is possible to effectively “hear” the difference at all. That, detective, is the right question (prof. Alfred Lanning).

And I can give you “my” very personal answer: with my ears and my audio equipment I cannot honestly hear ANY difference at all. The only reason I don’t buy cheap cables (both digital and analogue) is that their plastic breaks down in time. The cheap lighting cables that come with an iPhone don’t even last one year, especially because we use them on a daily base.

If you want to hear more you can watch the funny (but instructional) “Do USB Cables Make a Difference” video by the founder of PSAudio, Paul McGowan.

This is mis-understanding facts.
Cables can influence the digital signal but as long as the device receiving the signal decodes the digital signal correctly there is absolutely no mechanism by which the sound could be changed.
Maybe a very very cheap and nasty receiver may get some errors if the eye pattern is very poor, but the only effect on the sound could be dropouts and stuttering, not a change in sound quality.
I don't believe there is any DAC on the market which couldn't correctly read a data stream since they all use industry standard receivers.
If there was it would be just incompetent engineering, and to be avoided.

Fancy cables are just an example of "never give a sucker an even break" (W C Fields)

 

[zepplock]

And that is exactly why USB cables DO sound different (disclaimer: you can hear the difference only if you use extremely high end DAC, see below).

Any cable used to transmit data DOES introduce errors, this is a very well known fact, this is why when we want to avoid data transfer errors we use a communication protocol with “error checking”, if the data that we receive is NOT correct, we just send back a request to resend the data. This works great and this is why for example we can transfer files other the internet with no errors. Now, real data streaming (like audio) cannot do that, there is just not enough time to request another packet (packet: a set of a fixed number of bytes that the receiver is able to recognize with a start and an end), therefore streaming data CAN indeed have errors.

So the right questions to ask: how many data transmission errors there are in a cheap basic Amazon USB cable vs a thousand dollar cable, how many errors are introduced by the EMF surrounding the cable, and if it is possible to effectively “hear” the difference at all. That, detective, is the right question (prof. Alfred Lanning).

And I can give you “my” very personal answer: with my ears and my audio equipment I cannot honestly hear ANY difference at all. The only reason I don’t buy cheap cables (both digital and analogue) is that their plastic breaks down in time. The cheap lighting cables that come with an iPhone don’t even last one year, especially because we use them on a daily base.

If you want to hear more you can watch the funny (but instructional) “Do USB Cables Make a Difference” video by the founder of PSAudio, Paul McGowan.

Paul McGowan is a clown. Stop believing in everything on internet.

 

[Chuckser]

Leave this asynchronous data transfer aside and have a look at the data transfer protocol used to send audio information over an USB port using DSD. If you have at least some knowlegde in maths (keyword: fourier transformation) all it takes is to look up what pulse density modulation means, and then you can immediately rule out any of the claims about "more bass" "clearer hights" or "darker background" when people try to explain the difference in different usb cables.

Thank you for the science. Is that how the USB protocol works?

 

[amirm]

Any cable used to transmit data DOES introduce errors, this is a very well known fact, this is why when we want to avoid data transfer errors we use a communication protocol with “error checking”, if the data that we receive is NOT correct, we just send back a request to resend the data.

That is not the case at all or no one would be getting half decent audio out of their USB DACs and measurements would show such errors easily.

The reason this is the case is that analog signals meant to convey digital bits have huge amount of margin for errors. The only time bits get flipped is if the voltage value representing a 1 versus 0 is so close that the receiver can't distinguish the two ("eye" pattern Frank mentioned above). Protocols such as USB are designed such that this does not happen until you exceed the cable lengths recommended in the specification which is quite long in our world of audio.

I have actually tested this. To get any bit errors, I had to string three USB cables using two thin, low quality extensions. You can read about it here. To summarize, once I did that, I started to get both measurable and audible artifacts:

The graph at the bottom is without data loss. The top curve with wide "skirts" is with the extensions causing data loss. The total cable length to cause this was 23 feet.

Here is the link to listen to the audio impact of above (I think it is still there): https://www.dropbox.com/s/rdbweo5mkxsocpt/Behringer Extension cable without Iso Regen.wav?dl=0

We can't use communication protocols to correct such errors usually because of latency. By the time a message is sent to the host to retransmit and get the fresh new data (hopefully without loss), the DAC may have gone past the point where that sample needed to be played. On the Internet we deal with this with initial buffering where we read ahead a bunch of samples (as much as a few seconds worth) and then start to play. That way we can ask for lost data to be retransmitted and get it in time. This doesn't always work though even with large buffering and data doesn't come in time in which case the player just throws the data out and you get a glitch, or a pause. With multi-rate streaming, this often causes the player to switch to a lower fidelity stream. If you ever seen this happen, now you know why!

With the typical 6 foot or shorter USB cable used to connect DACs to hosts, data loss is simply not a factor. If it is, it would show up in my measurements since I use such a cable for all of my measurements.

Where there is an "analog" angle to this, is timing or clock. In the old days, the clock for DAC was extracted from USB stream. Such clock is subject to jitter both in the source and cable and did cause degradation. For the last 10+ years though, DACs have switched to asynchronous USB where the DAC has its own clock and uses USB for data retrieval. To the extent the data itself arrives without fault, then you are good to go.

There is a tertiary issue here and that is the USB ground leaking noise into the DAC or creating ground loops. No cable can fix these problems. Today's high performance DACs even at budget prices reject USB noise exceptionally well. Ground loop can get you but the solution to that is to use balanced output of a DAC. Fiddling with USB input has only a random chance of fixing anything.

 

[AudioSceptic]

And that is exactly why USB cables DO sound different (disclaimer: you can hear the difference only if you use extremely high end DAC, see below).

Really? Why would that be, and what do you mean by "high end" anyway?

Any cable used to transmit data DOES introduce errors, this is a very well known fact, this is why when we want to avoid data transfer errors we use a communication protocol with “error checking”, if the data that we receive is NOT correct, we just send back a request to resend the data. This works great and this is why for example we can transfer files other the internet with no errors. Now, real data streaming (like audio) cannot do that, there is just not enough time to request another packet (packet: a set of a fixed number of bytes that the receiver is able to recognize with a start and an end), therefore streaming data CAN indeed have errors.

Is this true? Is the data not buffered and the receiver has plenty of time (audio is low bit-rate) to ask for repeats of any broken data? And even if not, how would that reduce SQ without audible clicks or breaks?

So the right questions to ask: how many data transmission errors there are in a cheap basic Amazon USB cable vs a thousand dollar cable, how many errors are introduced by the EMF surrounding the cable, and if it is possible to effectively “hear” the difference at all. That, detective, is the right question (prof. Alfred Lanning).

And I can give you “my” very personal answer: with my ears and my audio equipment I cannot honestly hear ANY difference at all. The only reason I don’t buy cheap cables (both digital and analogue) is that their plastic breaks down in time. The cheap lighting cables that come with an iPhone don’t even last one year, especially because we use them on a daily base.

If you want to hear more you can watch the funny (but instructional) “Do USB Cables Make a Difference” video by the founder of PSAudio, Paul McGowan.

We can all agree that quality construction is a good thing, even if only to guarantee longevity (which works out cheaper anyway), but it is a fact that some expensive cables are more poorly made than cheap "basic" ones.

 

[ahofer]

And that is exactly why USB cables DO sound different (disclaimer: you can hear the difference only if you use extremely high end DAC, see below).

Any cable used to transmit data DOES introduce errors, this is a very well known fact, this is why when we want to avoid data transfer errors we use a communication protocol with “error checking”, if the data that we receive is NOT correct, we just send back a request to resend the data. This works great and this is why for example we can transfer files other the internet with no errors. Now, real data streaming (like audio) cannot do that, there is just not enough time to request another packet (packet: a set of a fixed number of bytes that the receiver is able to recognize with a start and an end), therefore streaming data CAN indeed have errors.

So the right questions to ask: how many data transmission errors there are in a cheap basic Amazon USB cable vs a thousand dollar cable, how many errors are introduced by the EMF surrounding the cable, and if it is possible to effectively “hear” the difference at all. That, detective, is the right question (prof. Alfred Lanning).

And I can give you “my” very personal answer: with my ears and my audio equipment I cannot honestly hear ANY difference at all. The only reason I don’t buy cheap cables (both digital and analogue) is that their plastic breaks down in time. The cheap lighting cables that come with an iPhone don’t even last one year, especially because we use them on a daily base.

If you want to hear more you can watch the funny (but instructional) “Do USB Cables Make a Difference” video by the founder of PSAudio, Paul McGowan.

Hoo boy. They keep coming with this nonsense.

 

[voodooless]

Is this true?

No it’s not. Cables might introduce errors, but that does not mean the will..

Is the data not buffered and the receiver has plenty of time (audio is low bit-rate) to ask for repeats of any broken data? And even if not, how would that reduce SQ without audible clicks or breaks?

USB audio does not do this, if data has errors, it will just glitch or play the bad samples. At least there is the possibility to check for errors. Other protocols such as mass storage might rerequest packets when errors occur, but for audio it was chosen not to do this for timing reasons. As Amir showed, in the vast majority of cases this is no problem at all.

 

[mansr]

what do you mean by "high end" anyway?

Broken.

 

[Raindog123]

The analog nature of digital communications (and consecutive practical utility of it) once and for all was addressed in IETF’s RFC2051 (in 2002). Little can be added to it since.

https://www.ietf.org/rfc/rfc3251.txt