# Gah. 'Audiophile' USB Cable.



## ry_goody

So I was looking to buy a new headphone cable and was trying to decide between headphile.com and ALO audio.
  
 Headphile has always seemed to me to just be a guy making audio and headphone cables out of materials that, people who believe in cables, know work well. That being just high purity solid core silver and high purity copper, no tricks or fancy buzzwords. Just plain old, single strand, high purity, solid core, copper and silver in a nice casing, done for you, so you don't have to do that, and then sold at a fairly reasonable price.
  
 But then I was looking at ALO and there fancy reference 16 cable http://www.aloaudio.com/reference-16-headphone-cable and it seems to me they have took a bunch of high purity, fibered copper cable, some of it silver plated, and woven a ton of it together, 8 fiber strands each way. They then sell this as there flagship? This throws up a bunch of red flags to me. For one, isn't superior sonic performance found only in solid core silver cables and not silver plated cables? Then secondly, isn't adding unnecessary gauge to an electrical wire detrimental to the signal?
  
 Then I stumbled across this on ALO http://www.aloaudio.com/cables/home-audio/digital $200 USB cable. Seriously? Digital is Digital. Thats when I had to think ALO is being over the top and crossing the scam line.
  
 But I post this because I'm not certain. Anyone have any experience with this or any thoughts?


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## cel4145

Since you posted here, you'll find someone that will champion the benefits of $200 USB cables. 

If you post in an audio forum where opinions are strictly based on scientific principles, everyone will tell you to buy something like this instead: http://www.amazon.com/AmazonBasics-A-Male-B-Male-Cable-Meters/dp/B00BCWA6TK/.


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## ry_goody

I just want to know, has anyone actually done any real tests on such a usb cable?


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## cel4145

ry_goody said:


> I just want to know, has anyone actually done any real tests on such a usb cable?




Why would anyone need to run "real tests" on a $200 USB cable if a <$10 USB cable can perfectly reproduce the audio stream. If you believe "digital is digital" as you said above, if you compare that cable to a working cheap cable, either there is no difference, or you will hear what you want to hear.


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## Chris J

July 2013 issue of HiFi News shows cleaner square waves in the expensive cables than in the cheap cable they tested.


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## ry_goody

cel4145 said:


> Why would anyone need to run "real tests" on a $200 USB cable if a <$10 USB cable can perfectly reproduce the audio stream. If you believe "digital is digital" as you said above, if you compare that cable to a working cheap cable, either there is no difference, or you will hear what you want to hear.


 
 A real test to me would be something that records the digital binary signal sent over the cable. Then you compare the two streams of binary data to see how different they are.
  
 Theoretically there could be missing or distorted bits due to signal degradation over distance, or static interference. But a digital signal with missing bits of data is a corrupted signal.


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## ry_goody

chris j said:


> July 2013 issue of HiFi News shows cleaner square waves in the expensive cables than in the cheap cable they tested.


 
 In USB cables?


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## Chris J

ry_goody said:


> In USB cables?


 
  
 Yes sir.
 USB cables.
 The cheap cable had a rather nasty looking square wave.


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## ry_goody

chris j said:


> Yes sir.
> USB cables.
> The cheap cable had a rather nasty looking square wave.


 
 Interesting, were they recording like the actual electrical signal over the USB cable directly?
  
 Or was it being fed into a DAC and then outputting a square wave from the DAC?
  
 Also, which DAC? Theoretically a USB cable stretched to far could get voltage fluctuations or interference, causing a corrupted byte package. But the USB receiver should be able to correct for this.


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## seeteeyou

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## cel4145

ry_goody said:


> A real test to me would be something that records the digital binary signal sent over the cable. Then you compare the two streams of binary data to see how different they are.




Or you just test to see if the cheaper cable reproduces an exact copy of the original signal at the other end. If so, no reason to test the more expensive cable. Who cares if it is also perfect since it costs $200. LOL


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## Lappy27

I tried:
  
 Generic cable
  
 WireWorld Starlight 7 : $110
  
 Transparent Performance : $100
  
 Silnote Poseidon : $595 but $250-300 street price
  
 Oyaide Continental 5S : $300
  
 Audioquest Diamond : $500
  
 AudioSensibility Statement USB : $350
  
 Transparent Premium : $550
  
 All these cables do sound different. Digital or not. Starlight and Transparent Performance, same price but complete opposite sounding and not in a subtle way trust me.
  
 My favorite and still in my system: Transparent Premium. Head and shoulders over all the others. Audiosensibility beeing 2nd. The best value IMHO followed by Silnote.
  
 Now, be prepared to read alot of comments from science vigilantes who will make fun of my REAL WORLD EXPERIMENTATION. They for the vast majority, never been willing to even compare generic and expensive cables. I did.


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## ry_goody

lappy27 said:


> I tried:
> 
> Generic cable
> 
> ...


 
  
 Now this is even more out of control.
  
 I could believe, very easily, in fact I do suspect and have experienced this, extremely cheap USB cables may conduct so poorly, or may be too long, or have interference, the voltage fluctuates in the cable causing bits to get corrupted. When I first got a USB DAC I used a really cheap, long USB cable and periodically the DAC would skip a sample, as most likely a bit packet got corrupted due to the inability of the cable to carry a signal with little fluctuation. A nice, shorter, usb cable fixed this.
  
 But at a certain point bit perfect on the other end is bit perfect, and there is no difference at that point. I mean when you copy a file to an external hard drive over a nice USB cable the file comes out exactly 100% the same as the source, otherwise it's corrupted, maybe the file might copy faster over a nicer cable, which would be an interesting test. But bit perfect is bit perfect, there would be absolutely 0 difference at that point. The only possibility that exists for what you say to be true would be if even the $500 cables are not achieving absolutely 'bit perfect' transmission and there are still samples slightly out of sync, and the receiving DAC does not correct this, and the material composition of the cable actually affects the transmission of bits through the cable by the voltage and amperage representation of the bit being affected predictably the same by the different materials. But you can test for this by recording a byte stream send over a usb cable and comparing it.


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## jimmers

chris j said:


> July 2013 issue of HiFi News shows cleaner square waves in the expensive cables than in the cheap cable they tested.


 
 Considering the test equipment HiFi News have (?), I thought the test procedure, just USB Eye Pattern, pretty pathetic.
 The 6,500 UKP/M cable's looked insignificantly different from most of the others, all were within eye pattern spec. even the freebie (which looked better than a 70 UKP/2m one).
  
 But then one writer for an English HiFi magazines, referring to USB cables, said
_"Normally, when you push music through a USB cable, the data, which arrives in blocks, includes narrow bits which represents the high frequency portions of the final music,,,_"
  
 You be the judge.


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## cel4145

For anyone into $500 USB cables, this Denon AK-DL1 network cable would be a nice supplement for connecting to one's router for improving audio quality of streaming music. There are some nice Amazon reviews for it


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## ry_goody

seeteeyou said:


> http://www.audiocircle.com/index.php?topic=117112.0
> 
> 
> 
> ...



 


This a quote from one of those links:

"I think this was probably for a SPDIF transfer - USB data is transferred in packets whose timing has no relationship to the the end data clock or content: it is self-transferred at the USB packet's clock rate to local memory and then replayed from that memory at the locally generated clock rate, being re-sampled by that clock in the process. The local clock is not derived in any way from the transmitted data's timing: it is simply locally generated at whatever rate the data instructions tell it to be. Jitter on the USB data itself affects nothing at all until it is so bad that actual data errors occur: as there is no error-correction applied, only error detection, the result of jitter this bad is gaps in the replay as packets are missed due to errors in transmission - and then only if re-transmission requests are ignored or the re-transmitted packet is still in error. The transmitted data is transmitted at one of a few pre-standardised clock rates, and usually simple timing derived from a local free-running high speed clock, not a PLL clock derived from the data rate, is used to self-clock the data into local memory."

This explains something that i was going to explain.

Basically the only way different USB cables could make a different in sound is if the USB receiving mechanism was implemented incorrectly in the DAC. A proper implementation of a receiving USB protocol means that the result on the other end is bit perfect, and if a packet arrives corrupted, it gets resent. 

This makes me ask, how did that hifi magazine test USB cables to get graphs that are different? Are they testing the actual voltage sent over the cable? Or the audio produced by a DAC on the cable, and if thats the case, whats the DAC? Because if different USB cables are producing different results on that DAC it means the USB mechanism was designed incorrectly.

Now I would say it's entirely possible that a lot of audio DAC's have incorrectly implemented USB receivers that do not correctly sort the incoming packets and send back proper signal to have a packet sent again, but these DAC's still sound good in how it was implemented and thus fancy USB cables seem to produce a difference. That is really the only way that a USB cable can make a difference, which basically means that a whole new market of fancy USB cables has been made by improperly trained engineers poorly implementing USB receivers on DAC's. Logically speaking here, someone claiming to here a difference in USB cables on their DAC I think is good reason to avoid that DAC because the USB mechanism was incorrectly implemented.

I really wish some USB audio engineer who knew a lot about this could respond... I am not completely closed to the possibility. I would just really like to understand, how?


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## seeteeyou

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## Chris J

jimmers said:


> Considering the test equipment HiFi News have (?), I thought the test procedure, just USB Eye Pattern, pretty pathetic.
> The 6,500 UKP/M cable's looked insignificantly different from most of the others, all were within eye pattern spec. even the freebie (which looked better than a 70 UKP/2m one).
> 
> But then one writer for an English HiFi magazines, referring to USB cables, said
> ...




Someone asked if there were test results out there.
I suggested HIFi News.

I don't really have any opinion other than that as I have spent almost no time comparing the sound of USB cables.


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## jimmers

chris j said:


> Someone asked if there were test results out there.
> I suggested HIFi News.
> You're reading too much into my comments.


 

 Sorry, but it wasn't about you.
  
 It was about HiFi magazines and my disappointment in some of them.
 These were my thoughts when I read the test initially back last year when my subscription downloaded the magazine to my iPad.
 I thought they could have used some ingenuity and devised tests that showed where the differences, if any, occurred.
  
 Perhaps I shouldn't have quoted you to introduce the article in question, it seemed the right thing to do as you were the one who first referenced that article, I thought that was the standard way of doing things here - quoting prior posts that introduce something new.
  
 Maybe someone can give me pointers on the correct forum etiquette.


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## Chris J

jimmers said:


> Sorry, but it wasn't about you.
> 
> It was about HiFi magazines and my disappointment in some of them.
> These were my thoughts when I read the test initially back last year when my subscription downloaded the magazine to my iPad.
> ...


 
  
 I owe you an apology. 
	

	
	
		
		

		
			




 I assumed you were taking a dig at me.   
  
 Actually I took more offence at our posts in the Q701 thread.
 I assumed you had mentioned that I was an Electrical Engineer in some sarcastic way.
  
 Again, my apologies, I misread your statement.


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## Chris J

jimmers said:


> Considering the test equipment HiFi News have (?), I thought the test procedure, just USB Eye Pattern, pretty pathetic.
> The 6,500 UKP/M cable's looked insignificantly different from most of the others, all were within eye pattern spec. even the freebie (which looked better than a 70 UKP/2m one).
> 
> But then one writer for an English HiFi magazines, referring to USB cables, said
> ...


 
  
 I agree.
 Looks crazy.  
	

	
	
		
		

		
		
	


	



 6,500 UKP/M cables....sheer insanity
 The narrow bits are high frequency content.......................I'm not expert in digital transmission, but that DOES NOT sound correct to me.


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## jimmers

chris j said:


> I owe you an apology.
> 
> 
> 
> ...


 
 All good.
 The quote from your profile was because I found it amusing - the "probably" bit, I wondered what the other reasons might be 
	

	
	
		
		

		
		
	


	




.


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## ampair

chris j said:


> I agree.
> Looks crazy.
> 
> 
> ...


 
  
 total, multiple bs...
  
 1) there are no narrow bits. every bit has _exactly_ the same length as all the others (e.g. 2 clock cycles in spdif). if it weren't that way, digital transmission would simply not work the way we are used to. plus, digital transmission protocols usually have some kind of clock syncing mechanisms implemented to reduce jitter and signal distortion effects. afaik in spdif, each packet is 32 bits wide, with up to 24 bits for the actual (mono) audio sample and 4 bits as sync'ing pattern. for a 44.1khz stereo stream this means 88,200 sync'ing signals _per second_.
  
 2) there is no variable frequency content per se in a digital signal.
 a) it consists of data represented by bits, and like i said, every bit takes exactly the same time, therefore the transmission frequency generally does not change.
 b) the analog audio signal may of course contain high frequency content (see c)), but the usb converter does not care about that. up until the pure decoded digital audio data hits the dac (ie, after it has passed the usb converter and the decoder), each packet/sample gets exactly the same treatment.
 c) electrically speaking, every digital audio sample contains one digitally encoded voltage level. fast voltage changes (ie high frequency) are represented as a change in the more significant bits in subsequent samples. but that's what the dac itself has to care about, it's of no concern to *all the entirety* of the usb chain.
  
 3) digital errors are of a statistical nature and do not result in a general change in sound signature. that means an error might hit (e.g. change the value from "0" to "1") any bit in any of the beforementioned packets with exactly the same probability, resulting in:
 a) barely to not audible if it hits a less significant bit
 b) massively audible if it hits a more significant bit (chirp, click and the like because the dac can't handle that big of a jump)
 c) complete signal loss if it hits one of the header bits describing the data contained in the packet, i.e. it does not get past the usb converter or decoder.
  
 to sum it up: if you don't experience signal losses or hear very audible errors, your cable is most likely not the source of the problem. if you're still not convinced, swap it for another cheap one to see if it makes any difference, before you go spending the big bucks.


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## jimmers

ampair said:


> total, multiple bs...


 

 That's why I put the quote there, as an illustration of the technical knowledge of some professional pundits.
  
 re: 1) above, in USB transmission the pulse width is not constant, but is a multiple number of clock cycles( I'll give him the benefit of the doubt, no, not really).
 So you are correct in saying each "bit" is the same length, but each pulse width is not. (just in case someone was visualising something different 
	

	
	
		
		

		
		
	


	




)
  
 Funny thing is the magazine excused his statement by saying he was quoting from a cable maker's site; I went to the site and the only mention of "narrow bits" was a quote from that review (chicken, egg?). WTH
  
 So I totally agree with what you say, (until someone can supply a *scientific* argument)


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## Chris J

ampair said:


> total, multiple bs...
> 
> 1) there are no narrow bits. every bit has _exactly_ the same length as all the others (e.g. 2 clock cycles in spdif). if it weren't that way, digital transmission would simply not work the way we are used to. plus, digital transmission protocols usually have some kind of clock syncing mechanisms implemented to reduce jitter and signal distortion effects. afaik in spdif, each packet is 32 bits wide, with up to 24 bits for the actual (mono) audio sample and 4 bits as sync'ing pattern. for a 44.1khz stereo stream this means 88,200 sync'ing signals _per second_.
> 
> ...




Well I wasn't really asking, because I didn't have a question, but thanks anyway....


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## ampair

chris j said:


> Well I wasn't really asking, because I didn't have a question, but thanks anyway....


 
  
 sorry, i just had to get that off my chest. some audiophiles just seem to believe they get more beautiful bits if they buy their digital cables from a dowser or a quantum healer.
  
 but yeah, you're welcome


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## Chris J

ampair said:


> sorry, i just had to get that off my chest. some audiophiles just seem to believe they get more beautiful bits if they buy their digital cables from a dowser or a quantum healer.
> 
> but yeah, you're welcome


 
  
 No harm done, really!
 All those other Head Fi-ers might enjoy your "rant".
 I don't mind paying a few bucks for a well built digital cable, but it must cost *LESS* than $1,000, if that isn't too difficult!   
	

	
	
		
		

		
		
	


	




 
 Er, much less.....
  
 BTW, nice to see all packets/sample get the same treatment, I'm all for peace, brotherhood, equality and unity amongst digital bits! 
	

	
	
		
		

		
		
	


	



  
 We are a very strange people here in Canada and have very strange ways if you haven't noticed.


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## Skyyyeman

USB cables are digital cables, which have significant differences between them, the same as analog cables.  See the below article entitled "Digital is Analog", featuring several top digital designers and manufacturers.
  
 Conversation with Charles Hansen, Gordon Rankin, and Steve Silberman
 By Michael Lavorgna  Posted: Jun 24, 2013
 ￼
 During a conversation with AudioQuest's Steve Silberman, Steve brought up the notion that "there's no such thing as digital" which I found thought provoking. I suggested to Steve that we have an email conversation about this very topic and Steve suggested adding Charlie Hansen of Ayre Acoustics and Gordon Rankin of Wavelength Audio into the mix. So that's what we did. The opening question:

 It's common for people to envision and represent a digital signal as a series of 1s and 0s. As such, there's really no room for error, at least according to this binary theory. Is a digital signal simply a series of 1s and 0s?

 Charlie Hansen: Unfortunately not. The "1"s and "0"s are just abstractions that are easy to think about. But in the real world, something real needs to represent those two abstract states. In modern digital electronics, we have almost universally chosen a voltage above a specific level (that varies from one "family" of electronic parts to another) to represent a "1" and a voltage below a different specific level (that again can vary) to represent a "0".
 In the real world, those two voltages are not the same, so there is a "grey" zone between the "black" of the "0" and the "white" of the "1". Also, it takes time for the signal to change levels, and the time required to do so can depend on dozens (or even thousands) of other external factors.

 "All of the problems with digital are analog problems."
 All of this can be boiled down to a simple phrase. "All of the problems with digital are analog problems."
 This is the primary reason that digital audio has taken so many decades to come close to the sound of analog. When digital audio was introduced, none of the top analog designers of the day knew anything about it. So it was all designed by digital engineers. Digital engineers have gone through years of training where these problems were never mentioned. And as time went on engineering schools put less and less emphasis on analog circuit design.
 There is an entire generation of designers that lacked even a basic understanding of analog electronics. And without a thorough knowledge of analog electronics, the problems of digital can never be addressed, let alone the problems of analog electronics, which will always be necessary. Currently good analog engineers are in high demand because there aren't many of them left! So a lot of schools are adding analog electronics back into their curricula.
 We live in an analog world, and all signals start as analog signals and must be returned to analog for audio playback. Modern video displays are about as close to pure digital as we've gotten so far, and even there the fact that there are still analog problems in digital electronics is what separates the good from the great.

 Gordon Rankin: Many people talk about digital data and bit perfect in a singular sense. But in reality things are very different. The testing involved with doing a real bit test is larger than anyone really would want to take on. Just using the obvious methods of the indication of a HDCD marker or recording a signal and taking the analog equivalent and subtracting them to see a difference only covers a really finite amount of what a true bit perfect test is. How about we take a song output over an S/PDIF transmitter to an S/PDIF receiver, record that and compare the two (original file and the data received)? Why stop at one song, but maybe 10, 20 songs, 8 hours worth.
 But aside from the data being true, there is so much more. How much energy is wasted delivering the data seems to have an effect on sound. As with increased energy usage the amount of EMI/RFI radiation also increases. This might be a reason why applications sound different. If we look at the "top" command in the Terminal application on OS X we see a programs usage and percent time and all the processes associated with that program. In practice the applications with the least required processing time also sounds the best. This may have an indication of why file types sound different. If you unpack a lossless file on the fly the processing time increases measurably and that tends to decrease the sound quality.

 "People talk about USB and Firewire jitter being an issue and it can cause data errors. But really this is not the audio related jitter error that is most important."
 Also how do we get the data there is a whole other topic to be taken on. We are basically packing audio data up into finite packets of bytes and then sending them over some serial link, one bit at a time and then rebuilding this data into a format for which the DAC chip will accept. People talk about USB and Firewire jitter being an issue and it can cause data errors. But really this is not the audio related jitter error that is most important. That has to do with the way the DAC receiver formats output data to the DAC chip and the associated audio master clocks and audio serial format (I2S, left justified, right justified, DSD, etc...). Then there is flow control over the network from the computer to the DAC. I don't know if any of you are looking at this... I have and it's not a pretty sight. So just doing this on average is not a good thing and there is an appreciable difference in sonics depending on the way you handle this.
 Anyone who feels it's only "1" and "0" is missing a ton more variables that need to be addressed.

 CH: The complete system used for CD's was developed before CD-ROMs were used for computers. It was only later when people started to realize that a CD could hold MUCH more data than any other transportable medium of the time (eg, 650 MB for a CD-ROM versus 1.2 MB for a 3-1/2" high-density floppy disk) that they adapted the CD for use with computers.
 There are several very clever back-up and redundancy systems built into the audio CD format so that it is fairly rare for there to be an actual error in the bits (eg, a "1" will be misinterpreted as a "0" or the converse). However, the error rate is still too high to be used for computer files, so another layer of error correction is added to a CD-ROM in addition to all of the error correction systems found in a CD.

 NB:Copying an audio CD to a CD-ROM will NOT use this extra layer of error correction, so there is no reason to copy all of your audio CD's to CD-ROM's. However if you rip your CD's to your hard drive using a system such as AccurateRip (employed in several ripping programs, such as dBpoweramp, see wiki.hydrogenaudio.org/index.php?title=AccurateRip for additional information), the checksum from your disc rip is compared to hundreds (or even thousands) of other submissions from other users and you can be confident that the audio data on your hard drive is a bit-perfect copy of the original master used for the CD. At this point, the data correction built into your hard drive will take over and protect your audio albums from any possible corruption -- at least until your hard drive fails. This is inevitable -- ALL hard drives will fail sooner or later, so be sure to BACK UP your music files!)
 Getting back to the "grey zone" that exists between a "0" and "1" in ANY digital system, it is rare that the errors are so large that there will be actual corruption of the data. It can happen -- most people have seen a digital display connected with a cable that is either poor quality and/or too long for its intended purpose. Often this will show up as green "streaks" in the picture. It can also happen with audio. If the cable connecting the DAC to the computer is either poor quality and/or too long for the system in use, there may be randomly audible "ticks" or "pops" during playback.
 "But since digital audio is a streaming system, the timing of the bits is critical. If the bit changes to the correct state but at the wrong time, this is equivalent to changing to the wrong level at the correct time."
 However, it is important that ALL audio systems will suffer ill effects from this "grey zone" even if there are no obvious audible problems. This is because the error is not large enough to change the state of any particular bit. But since digital audio is a streaming system, the timingof the bits is critical. If the bit changes to the correct state but at the wrong time, this is equivalent to changing to the wrong level at the correct time. These timing errors are known as "jitter".
 [GR: Audio streaming protocols are typically not error correcting. Standard Asynchronous and Adaptive protocols only cover flow control, not error control. The analog behavior at the receiver side of any streaming interface can have a lot of effect on the quality of the received data which will directly reflect the quality of the audio.]
 It is rather unfortunate that jitter was the first timing error to be described in the context of digital audio, as it has become by far the most common way to refer to timing errors. But it turns out that far more important than the absolute amount of timing error is the spectral distribution of the error (ie, how much error is there at high frequencies versus low frequencies), and whether that timing error is correlated with the audio data (music signal) or if it is just random variations.
 More sophisticated test equipment is required to test for this, and you will see this referred to as "phase noise". The phase noise is measured at a frequency that is offset from the desired carrier frequency. A graph of the phase noise versus the offset frequency provides us with information regarding the spectral distribution of the jitter, and is the best tool to date for measuring timing errors (ie, "jitter") in audio equipment, as it is the most sensitive tool and has the highest correlation with audible differences.

 AS: Since there's no such thing as 1s and 0s in digital transmission, what is being sent over our USB/Firewire/Ethernet cables when we play back music files?
 CH: An ANALOG signal!

 Steve Silberman: I think this is where things get misconstrued. The signals we think of abstractly as “digital” are in fact high-speed analog square waves, susceptible to all of the same damage and distortions as any other analog signal.

 AS: So when we talk about digital music playback, we're talking about a continuous system as opposed to a discrete system. In effect, once we hit play, our data is transformed from a discrete state into a continuous state which is, for all intents and purposes, governed by the laws of the analog world. And one of the most critical aspects of this continuous music playback system is time/timing errors/jitter.

 GR: One thing that people have to realize is that these type of interfaces all work differently. I think that cable companies had to overcome when computer audio hit the market was... this stuff is all different than an S/PDIF cable. Which was really the only digital cable most of these companies had any experience with.
 These interfaces all come with protocols which make not only the electrical aspect more demanding, but also details that are not apparent in S/PDIF cables.
 "The turnaround time is the amount of time the cable settles to allow the other end to start transmitting without the signal being corrupted."
 I would add one really key component to the list [time/timing errors/jitter]—what is called "turnaround". All of these protocols are asked for some kind of response. The turnaround time is the amount of time the cable settles to allow the other end to start transmitting without the signal being corrupted. It has to do with capacitance, length and impedance. For example some companies were making 50 foot USB cables stating they kept the capacitance low enough to make this work. I asked if they tested it on any asynchronous USB DACS and the answer was no. Well the problem was the host was never seeing the feedback pipe which made the DAC under or over run. The turnaround on these cables was sooooo long that when the DAC was asked to send the feedback pipe data that it was all corrupted when it reached the host.
  
 AS: What about digital filters? How does a digital filter differ from an analog filter and doesn't this difference point to a digital "state" within the playback chain?

 CH: As we have seen, "digital" itself is a very abstract concept. In the real world, there is some real physical quantity that represents "digital". For example, when the voltage exceeds such-and-such a threshold we define that as representing a "1".
 But there is one place where our abstract concept (of the human brain) becomes (in a very strange way) tangible. And that is inside the electronic brain of a digital computer. Now the term "digital computer" can encompass a wide variety of things, from a simple gate that compares two signals to a sophisticated modern PC with billions of transistors operating at thousands of megaHertz.
 When this electronic brain receives signals that represent 0's and 1's, it will carry out a very specific set of operations on those numbers as if they were really and truly digital. A good example of this is when one sees the image frequencies created by a digital sampling system. In the textbooks, these image frequencies repeat at multiples of the sampling frequency and go on forever -- to infinity and beyond!
 This also happens inside the electronic "brain" that performs the computations, but as soon as the signal comes out into the real world, it has to conform to the real physical laws. For the image frequencies to continue forever, the impulses from the DAC chip would have to be infinitely narrow. Of course something infinitely narrow wouldn't exist. So a mathematician named Paul Dirac invented an abstraction called the "Dirac delta", where delta refers to a change. So it is an imaginary pulse that is infinitely narrow, but to have any energy it would also have to be infinitely tall. Of course such a thing cannot exist in the real world, but it exists in the equations created by digital mathematicians and calculated by the digital "brains" inside digital equipment.
 As soon as that imaginary pulse comes out into the real world, the digital "brain" gives instructions to real switches that cannot change states with infinite speed. So they are stretched out to have a finite time, and this causes changes in the actual frequency response compared to the theoretical response.
 But inside the "digital brain" of the equipment (and the brain of the digital engineer) is the only place that the signals are truly digital.
 "But inside the "digital brain" of the equipment (and the brain of the digital engineer) is the only place that the signals are truly digital."

 GR: When people ask me about digital filters I always have to remind them that most of the math we use here for digital filters was derived by the work of LaPlace and Fourier in the early 1800's. Remember to them, there was no computer. This math involves two tables, one of samples the other coefficients which make up the filters. A table with the audio data is multiplied by a table with the filter coefficients and accumulated to form a new output sample. LaPlace and Fourier therefore worked with infinite math models. Not 32 bit floating point, 24, 32, 64 fixed point math models. They assumed you had all the time in the world to do these computations, instead of in between two samples.
 "...the larger you make the coefficient and the sample work into a larger model say 64, 72 bits or higher and don't over or under-run the math model, then the better it's going to sound."
 This is why filters all sound different. A coefficient is less than 1, so it's a fraction. If you look at this as we do, then all the math here is fixed point, meaning there are no fractions. We multiply the coefficient by some factor, usually a multiple of 2, because we have to divide that out in the end to make the output sample correct. In fixed math it's faster and easier to divide by rotating the data right one spot (divide by 2) or 2 spots (divide by 4). But as Charlie has found out and something we were taught at school, the larger you make the coefficient and the sample work into a larger model say 64, 72 bits or higher and don't over or under-run the math model, then the better it's going to sound. Most commercial chips used 24 bit models for their math to make the chips cheaper. Some companies have really come around [and are building DAC chips with higher precision math models] and that is why the chips sound better and more realistic.

 AS: To be continued...
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----------



## Chris J

Oh man.
 Holy wall of text!
 You could have just posted a link!


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## Skyyyeman

chris j said:


> Oh man.
> Holy wall of text!
> You could have just posted a link!


 
  
 Couldn't find the link


----------



## cel4145

skyyyeman said:


> Couldn't find the link




Use Google.


----------



## Skyyyeman

cel4145 said:


> Use Google.


 
 Gee, that's really a great idea.  (But I already had it in a Word doc so that's what I used, since I didn't want to go searching around and waste more time.)


----------



## cel4145

skyyyeman said:


> Gee, that's really a great idea.  (But I already had it in a Word doc so that's what I used, since* I didn't want to go searching around* and waste more time.)




Took me 10 secs to find it.


----------



## Skyyyeman

cel4145 said:


> Took me 10 secs to find it.


 
 Excellent job, way to go!!
  
 Frankly, I didn't even bother to search since I already had the text (but without the link, after looking for it in my doc for maybe 1/500 of a sec). Time to put this major Google/search/link issue to rest and move on to the lesser issue of USB cables, the article itself, 1s and 0s, etc.


----------



## Skyyyeman

cel4145 said:


> Took me 10 secs to find it.


 
 BTW, I happen to agree with your earlier comments.  I've experienced significant differences between digital cables, including USB cables.


----------



## jimmers

chris j said:


> Oh man.
> Holy wall of text!
> You could have just posted a link!


 
 And not much of it had to do with USB cables, and otherwise kinda misses the point (if there was one(?)) 
	

	
	
		
		

		
		
	


	




.


----------



## ab initio

skyyyeman said:


> Spoiler: Warning: Spoiler!
> 
> 
> 
> ...


 

 At best, this article is misleading. More likely, it is flat out wrong.
  
 This article has already been linked to before in the various previous discussions on USB cables, and it is still grossly misguided, which has been pointed out in previous discussions. The article lacks a basic understanding of information theory, and perversely confuses (whether intentionally or not) discrete-time signal theory with digital data. It makes absurd claims like "digital _is_ analog!"  when digital is discrete time and discrete amplitude, while analog is continuous in time and in amplitude.
  
 If a USB cable meets the USB technical specifications, and the devices it connects conform to the technical specifications, then everything works as planned---identically to any configuration involving any other USB cable _that also meets the USB specifications_. If swapping USB-spec cables changes the integrity of the data transferred from one device to the next, then at least one of those devices (or cables!) is broken. If swapping USB-spec cables changes the integrity of the power transferred from one device to the next, then at least one of those devices (or cables!) is defective (or was exceedingly poorly designed).
  
 USB cables (a) deliver audio data to a DAC (perfectly when operating within spec) and (b) deliver power to bus-powered devices (which DAC designers _should_ account for USB spec's on power delivery).
  
 Hope this helps clarify USB cables for audio applications.
  
 Cheers
  
 EDIT: Since this whole thread digressed into the technical details of USB audio and USB audio hardware (i.e., USB cables), it seems like a better place for this thread would be in the Sound Science forum. (duhn, duhn, duuuuuuuuuhn! I know, run and scream in terror! not sound science!)


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## BadgerCow

How do i delete this? oh never mind


----------



## jimmers

ab initio said:


> EDIT: Since this whole thread digressed into the technical details of USB audio and USB audio hardware (i.e., USB cables), it seems like a better place for this thread would be in the Sound Science forum. (duhn, duhn, duuuuuuuuuhn! I know, run and scream in terror! not sound science!)


 





  I think the main problem is that it digressed away from USB cables, but you are right 
	

	
	
		
		

		
		
	


	




 .
 (it seems we share a hobby 
	

	
	
		
		

		
		
	


	




).


----------



## ampair

you just spared the public from another rant by me, containing (aside from the usb specs thing) 2-conductor wave propagation, fall/rise times, frequency dispersion and so on.
 well played, seems like we are on the same wavelength 
	

	
	
		
		

		
		
	


	



  
 and no objections about the sound science thing. i love science (electrical engineer speaking here 
	

	
	
		
		

		
		
	


	




)
  
 Quote:


ab initio said:


> At best, this article is misleading. More likely, it is flat out wrong.
> 
> This article has already been linked to before in the various previous discussions on USB cables, and it is still grossly misguided, which has been pointed out in previous discussions. The article lacks a basic understanding of information theory, and perversely confuses (whether intentionally or not) discrete-time signal theory with digital data. It makes absurd claims like "digital _is_ analog!"  when digital is discrete time and discrete amplitude, while analog is continuous in time and in amplitude.
> 
> ...


----------



## Chris J

ab initio said:


> At best, this article is misleading. More likely, it is flat out wrong.
> 
> This article has already been linked to before in the various previous discussions on USB cables, and it is still grossly misguided, which has been pointed out in previous discussions. The article lacks a basic understanding of information theory, and perversely confuses (whether intentionally or not) discrete-time signal theory with digital data. It makes absurd claims like "digital _is_ analog!"  when digital is discrete time and discrete amplitude, while analog is continuous in time and in amplitude.
> 
> ...




Oh no!
not the Sound Science Fiction (and amateur psychology) Forum!:eek:


----------



## cel4145

skyyyeman said:


> BTW, I happen to agree with your earlier comments.  I've experienced significant differences between digital cables, including USB cables.




I think you have me mixed up with someone else who posted. I'm in the "if the USB cable is well made, there's no difference" camp. A $5 USB cable can often easily do the job.


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## x838nwy

It's amazes me how many people claim their approach as being scientific while talking about things they have never even tried but could easily do so at virtually no cost to themselves.

Do remember that science also said that the earth is flat and that humans can't hear beyond 20kHz. And CD's are perfect sound forever. Perhaps sending my music over bluetooth is just as good as a coax spdif cos digital is digital.

Shouldn't one approach things with curiosity rather than prejudice? Anyway, it's comforting to know there are members here who already know everything.


----------



## ab initio

x838nwy said:


> It's amazes me how many people claim their approach as being scientific while talking about things they have never even tried but could easily do so at virtually no cost to themselves.
> 
> Do remember that science also said that the earth is flat and that humans can't hear beyond 20kHz. And CD's are perfect sound forever. Perhaps sending my music over bluetooth is just as good as a coax spdif cos digital is digital.
> 
> Shouldn't one approach things with curiosity rather than prejudice? Anyway, it's comforting to know there are members here who already know everything.


 

 You do realize that there are actually people who have read the USB specifications and data sheets for the usb chipsets, and who know the fundamentals of electric and electronic circuits and information theory from their undergraduate engineering education.
  
 A famous quote that is frequently attributed to Sir Isaac Newton is


> If I have seen further it is by standing on the shoulders of giants
> -Sir I. Newton [1]


 
 What he is saying, is that his advances in science are possible only by virtue of the body of knowledge established by his predecessors. This is an important concept that only a few people seem to grasp; namely, we don't have to reinvent the wheel every time we want to invent a chariot, wagon, train, or car. Furthermore, once we establish a principle like "round wheels roll", we can use wheels---without reinventing them from first principals--- to build many cars. The previous scientific advancements in the field of semiconductors, quantum mechanics, E&M field theory, etc. are already established; hence, we can move forward and do things like make devices that communicate using USB cables.
  
 USB is not at the forefront of the scientific frontier. If you're interested in that, look at things like quantum computing. Don't project your own personal lack of understanding of the topic onto the rest of the world. The one who is unscientific is the one who chooses to disregard the body of overwhelming existing knowledge on all the principles at play (not only in USB audio devices, but everything) but bases one's beliefs in unfalsifiable claims or falsifiable claims for which no evidence is presented.
  
 Finally, I just want to correct some of the inaccuracies in the post above. CD audio is encoded as a pulse code modulation data stream with a bandwidth that encompasses the range of average human hearing. It is capable of fully encoding the information in this audible range with a worst-case-secnario dynamic range of 96 dB (and at most frequencies, can be much more with correct use of noise-shaped dithering). This data can be transferred over digital communication interfaces with sufficient data bandwidth (1,411.2 kbit/s, such as usb, spdif, etc.) _without loss of information_. Therefore, any player on the receiving end can recreate the audio sent via these interfaces with precision limited only by the capabilities of the device.
  
 On the other hand, bluetooth audio is subject to the AD2P profile and is limited by the available bandwidth to less than 768 kbit/s. Naturally, audio information cannot be sent at maximum fidelity. Instead, lossy audio compressing is used to fit the stereo audio information in this limited bandwidth and places a limit on the fidelity of the resulting audio stream on the receiver's end. Therefore, no, "bluetooh is not as good as CD, spdif, etc." as the previous poster postulated.
  
 I hope everybody can learn a little bit from the information in the post!
  
 Cheers


----------



## x838nwy

ab initio said:


> You do realize that there are actually people who have read the USB specifications and data sheets for the usb chipsets, and who know the fundamentals of electric and electronic circuits and information theory from their undergraduate engineering education.
> 
> A famous quote that is frequently attributed to Sir Isaac Newton is
> What he is saying, is that his advances in science are possible only by virtue of the body of knowledge established by his predecessors. This is an important concept that only a few people seem to grasp; namely, we don't have to reinvent the wheel every time we want to invent a chariot, wagon, train, or car. Furthermore, once we establish a principle like "round wheels roll", we can use wheels---without reinventing them from first principals--- to build many cars. The previous scientific advancements in the field of semiconductors, quantum mechanics, E&M field theory, etc. are already established; hence, we can move forward and do things like make devices that communicate using USB cables.
> ...




Oh noes. You mean there'a spec?? No Way!!!

The body of knowledge of which you apparently possess is merely a basis for hypotheses. Your is that a usb cable as long as it is functional, cannot have any influence in the final reproduced sound. The science happens when you go test that hypothesis. Sir Issac, the man you quoted, would not have just put two and two together and claimed that it works without testing it. You quote engineering facts but it seems you do not know how to make the most of those facts.

Would it be too much to get yourself a few usb cables to try and return them all if you find you are right? Why keep dragging on about nothing but assumptions? I grant you they are based on a few facts, but you should know well that it is never possible to consider ALL the facts and an assumption is just a polished guess until it is proven.

As for the bt specs, bt 2.o can do 2Mbits/sec. Your figures are for v.1.2.

And what does reading the specs. Have to do with making good cables? We've known audio rca interconnect specs. For ages. Heck we've known about tubes and transistors for decades but amps are still getting better and better. Shockingly without using any alien tech or anything. By your logic, that should not be possible.


----------



## x838nwy

> The one who is unscientific is the one who chooses to disregard the body of overwhelming existing knowledge on all the principles at play (not only in USB audio devices, but everything) but bases one's beliefs in unfalsifiable claims or falsifiable claims for which no evidence is presented.




You know, a while ago, there was overwhelming evidence that the earth was the center of everything. And no, I did not try these cables out because I *believed* in anything. I was curious to see if there's any difference. I have no truck with the people who made them cables. I have no means of un/falsifying my claims other than to ask you and others to try a similar experiment and share your findings. If anyone is happy to lend me their measuring tools, I'd happily test my cables for them. For now, I'll have to use my ears.


----------



## elmoe

As long as a cable is made properly, there will be no difference whatsoever, whether it's a USB cable or a pair of interconnects. You think I'm wrong because I haven't tested this? See my profile. I have a pair of BM Pinnacle Gold interconnects that retail at 999USD. They sound exactly the same as my Cardas 300b interconnects (copper) which are about 10 times cheaper. Good thing I bought em used for 150usd. 
	

	
	
		
		

		
			





 
  
 Most of the expensive cables I own I bought way back when I was still easily influenced and let placebo dictate what I heard. Years later, doing serious comparisons, I found no differences whatsoever. Now I just use em cause they look pretty connected to all my gear. 
	

	
	
		
		

		
		
	


	




 
  
 I also own a decent (read: expensive, although not TOO expensive) BNC to RCA digital cable, and a few (much cheaper) TOSlink optical cables. Guess what? They all sound the same.


----------



## cel4145

x838nwy said:


> Shouldn't one approach things with curiosity rather than prejudice? Anyway, it's comforting to know there are members here who already know everything.




If someone wants to believe in fairies and unicorns, that's their business. But it doesn't make me lacking in curiosity or prejudiced because I choose instead to follow logic and science.


----------



## x838nwy

cel4145 said:


> If someone wants to believe in fairies and unicorns, that's their business. But it doesn't make me lacking in curiosity or prejudiced because I choose instead to follow logic and science.




Following logic and science leads you to just shut the door to any possibility whatsoever of the usb cable making any difference in sq? Congratulations.

Look, I've had my fair share of tweaking my system. Sometimes it works sometimes it doesn't. I have a shakti stone to show for it too. There's a lot of bs around this hobby for sure, but happily not all of it is bs. I'm a big fan of blue jeans cable and before that Naim audio equipment (and back in those days no-one made cables for Naim gear). I was using a perfectly functioning usb cable and was part of the 'digital is digital' crowd when it seems a worrying number people are talking about usb cables. I read up on it and decided to try a couple out. One wasn't too different from my old cable and the other was significantly different. Then i got a few more and it appeared that i can more readily tell usb cables apart than rca interconnects. This was odd but again there appeared to be some explanations as to why. What's interesting is that folks who say usb cables matter aren't always people who make or sell them. Many aren't reviewers either. Google is your friend here, search and you shall find.

All i am saying is that if you trust in reason and logic, it should lead you to a 15 day return policy in a heartbeat. Many of these cables aren't expensive and many are very good. I will not say that spending $300 on a cable is worth the 'same' amount of difference if you spend it on other gear, but it can make your stuff sound better. It also seems to be dependent on the equipment involved. My pwd is not hugely susceptible but does improve while the gungnir shows the differences quite significantly. Try it. You don't have any thing to lose, do you?

@elmoe it seems odd that you paid 150 for a 1k cable. There are a lot of fakes and scammers around. Anyhow, what other cables have you tried (and found to be worthless)? I'd like to know what to avoid. A lot of places have good return policies - why not return them?

At the end of the day, we all have to live our karma. If mine means i must pay crazy sums for cables, well at least i ain't buying crack with it i guess.


----------



## elmoe

x838nwy said:


> Following logic and science leads you to just shut the door to any possibility whatsoever of the usb cable making any difference in sq? Congratulations.
> 
> Look, I've had my fair share of tweaking my system. Sometimes it works sometimes it doesn't. I have a shakti stone to show for it too. There's a lot of bs around this hobby for sure, but happily not all of it is bs. I'm a big fan of blue jeans cable and before that Naim audio equipment (and back in those days no-one made cables for Naim gear). I was using a perfectly functioning usb cable and was part of the 'digital is digital' crowd when it seems a worrying number people are talking about usb cables. I read up on it and decided to try a couple out. One wasn't too different from my old cable and the other was significantly different. Then i got a few more and it appeared that i can more readily tell usb cables apart than rca interconnects. This was odd but again there appeared to be some explanations as to why. What's interesting is that folks who say usb cables matter aren't always people who make or sell them. Many aren't reviewers either. Google is your friend here, search and you shall find.
> 
> ...


 
  
 It's not odd at all, I bought it from a well-known Head-Fier, so there's no doubt about the legitimacy of the cable. Cables tend to drop big time in price over time. None of the cables are worthless, they all do exactly what they were made to do, and exactly the same way. Some cost 50 bucks, others 1000. That's all. As for returning them, I bought them 7-8 years ago so that's unlikely.
  
 Once again though, none of these cables are worthless. You can look in my profile for my list of cables. What I'm saying is that at the end of the day, they make no difference to the sound. Some of them are sturdy and well built, which is now the ONLY factor that goes into me putting money into a cable, but with years and years of testing, I have found that as long as the cable is built properly, it will sound the same whether it costs 50 or 1000 bucks. Any difference I may think I heard was in my opinon, complete placebo.
  
 I'll add that I've had cables that are recognized far and wide for being 'amazing', such as moon-audio cables, headphile recables, enigma audio cables, cardas... I particularly liked the sturdyness of the enigma audio cables, but as far as sound goes, they all sound the same.


----------



## x838nwy

I wouldn't call any cable 'amazing' as such. Like i said, a difference between a $100 and a $500 cable is probably about $100 if you could put it to scale, so to speak. But to say they're all the same i find to be strange. There is a brand of cable which i think is a waste of money but the rest i find to actually have an effect. Some more positive than others, obviously.

Anyhow i guess you're lucky. I don't throw too much cash at it, but it's still a cost and to me a necessity to an extent.

I do not feel i'm experiencing placebo, however. A lot of the time, it's not the nest looking or the most expensive cable i choose. I'd guess someone affected by placebo would immediately and consistently choose what she/he assumes to be the more costly or at least look that way, surely.


----------



## 00940

ab initio said:


> USB cables (a) deliver audio data to a DAC (perfectly when operating within spec) and (b) deliver power to bus-powered devices (which DAC designers _should_ account for USB spec's on power delivery).


 
  
 That's a bit short.
  
 The transfer of data itself isn't much of a problem. The real technical problem with the various USB audio protocols is the reconstruction of the timing information. As for (a), I wouldn't expect the USB cables to have a significant effect on the shape of the signal and the final reconstructed audio clock only has an indirect link with packets timing anyway (in adaptive mode); or even none (in asynchronous mode). However, for (b), the clock generation sections of the USB receiver are extremely sensitive to what is fed to their power pins (V+ and gnd). Life being what it is, DAC designers usually don't go to the extremes required to make sure that noise entering the USB device is completely neutralized (especially common mode noise). When the whole USB device is USB powered, we can extend the problem to the D/A process itself.
  
 Which is why _objective differences_ have actually been _measured* _in between usb cables (all other parameters being kept equal). They were registered as differences in the analog result which can be attributed to jitter in the digital chain. Those differences can probably be attributed to variations in shielding, separation of data, gnd and power lines, common mode noise filtering, etc.  among the measured cables.
  
 But, and that's what matters most, the audiophile cables aren't necessary better than common ones and those differences are likely under our hearing abilities. Variations in the quality of your USB source are way, way more significant and USB cables are a completely mistaken place to look at for improvements.
  
_* by Paul Miller, in Hifi-News of January 2011 _


----------



## cel4145

x838nwy said:


> Following logic and science leads you to just shut the door to any possibility whatsoever of the usb cable making any difference in sq? Congratulations.




No. It just means I'm looking for scientific explanation that trumps the existing explanation, rather than listening to some guy on the Internet who has to be rude and/or insult those that don't believe in USB cable audio superiority in order to make his points. 00940 just provided one reason why it might sound better to you--it is possible that a poorly designed DAC would need a cable with better shielding. That has nothing to do with one USB cable being inherently better than another for audio quality.


----------



## elmoe

Don't listen to 00940 too much - a Belgian exiled in Paris is way too suspicious - it's usually the other way around


----------



## z3r0day

It all depends on the shielding material used. Electromagnetic interference could cause bits to be flipped. Other than that, I don't think conductor used make a difference for digital signals.


----------



## jimmers

ab initio said:


> I hope everybody can learn a little bit from the information in the post!
> 
> Cheers


 
 Maybe not, but agree I do.


----------



## x838nwy

cel4145 said:


> No. It just means I'm looking for scientific explanation that trumps the existing explanation, rather than listening to some guy on the Internet who has to be rude and/or insult those that don't believe in USB cable audio superiority in order to make his points. 00940 just provided one reason why it might sound better to you--it is possible that a poorly designed DAC would need a cable with better shielding. That has nothing to do with one USB cable being inherently better than another for audio quality.




I was not being rude to non-believers, but instead stated that i found it silly that with all the logic and so-called science it was concluded that "we know everything - digital is digital and that's that". Excerpts form interviews of famous designers of digital audio have been posted, someone posted links to a number of articles. Still it was "i know everything - it's impossible". So why should one more article make a difference? (I did state that there's information out there on the web.) i appreciate 00940's post as much as the others, but it's not the first one linked to from this thread.

My point since the beginning was that with evidence on *both* sides (as according to various articles and links) and if it interests you, it is the scientific thing to test your hypotheses. That is all. But still... "we know usb specs. My printer works perfect." You demand proof in the forms of graphs and plots for 'audiophile cables' but are you even sure your usb 2 cable conforms to that standard? You're basing your assumption on the fact that it works. How is that different from someone else basing their hypothesis on what they hear? There's concrete information than that on the "heard the difference" side but for some reason, all is dismissed as placebo. 100% placebo. Because digital is digital. It can't be any other way.

Now you're saying you believe it may be the case depending on how well dacs are designed. Well, which of the hundreds of dacs out there is perfectly designed? Most dacs of a common price range use one of a handful of chips available to handle usb inputs (like an xmos). The designs of these boards do tend to be more limited than the rest of the dac and more importantly, similar between different dacs. If a cable makes an improvement on one, it is likely to do so on another. So in these cases, the cable matters. A berkeley audio usb->spdif box goes to great lengths to deal with its usb input and with stunning results. Where's the logic of "perfect" data transfer with any "functional" cable and circuits in that one? Still 100% placebo?

And the shielding.... Well isn't that part of the cable? The shielding, construction, materials, connectors etc. each play a role to a degree. I've never said a good cable needs to be made out of gold and covered in unobtainium or something, did i?

Look, you can believe what you like. I am seriously not interested. But please, if you want to be scientific about it, please keep an open mind and check things out. It is easy to put things down to as placebo effects and it is dangerous too because it is hard to disprove that something is NOT placebo. It's easy to read specs but it is harder still to understand their limitations upon application. Folks throw around words like double blind tests like it's easy or even possible to do in many cases. There's a lot of bs in this hobby like i said, but it ain't all bs. Seeing for yourself is part of the fun, imho, specially if it costs you nothing.


----------



## z3r0day

x838nwy said:


> I was not being rude to non-believers, but instead stated that i found it silly that with all the logic and so-called science it was concluded that "we know everything - digital is digital and that's that". Excerpts form interviews of famous designers of digital audio have been posted, someone posted links to a number of articles. Still it was "i know everything - it's impossible". So why should one more article make a difference? (I did state that there's information out there on the web.) i appreciate 00940's post as much as the others, but it's not the first one linked to from this thread.
> 
> My point since the beginning was that with evidence on *both* sides (as according to various articles and links) and if it interests you, it is the scientific thing to test your hypotheses. That is all. But still... "we know usb specs. My printer works perfect." You demand proof in the forms of graphs and plots for 'audiophile cables' but are you even sure your usb 2 cable conforms to that standard? You're basing your assumption on the fact that it works. How is that different from someone else basing their hypothesis on what they hear? There's concrete information than that on the "heard the difference" side but for some reason, all is dismissed as placebo. 100% placebo. Because digital is digital. It can't be any other way.
> 
> ...


 
  
 No need to get upset. As long as the conductor works, it does not affect signal quality, aka 0s and 1s. Shielding is the only possible way to protect the transmitted data.
  
 Yes. Transmitting electrical signals is all the cable does. You can't just argue something out of nothing.
  
 Everything else is placebo (not necessary a bad thing).


----------



## x838nwy

z3r0day said:


> No need to get upset. As long as the conductor works, it does not affect signal quality, aka 0s and 1s. Shielding is the only possible way to protect the transmitted data.
> 
> Yes. Transmitting electrical signals is all the cable does. You can't just argue something out of nothing.
> 
> Everything else is placebo (not necessary a bad thing).




When was it mentioned that some magic happens to electrical signal? The main point here is whether or not using different cables make a difference for a usb connection between your pc and dac. Some say yes, some the opposite. Something was never argued out of nothing, but if you say shielding matters, then the connectors matter. The construction of the cable matters and so on as these affect how well the entire cable is shielded.

The sq wave plots i think matters. If that has something to do with materials then so be it. I'm interested in the end result and that's what we're talking about here.


----------



## cel4145

x838nwy said:


> I was not being rude to non-believers, but instead stated that i found it silly that with all the logic and so-called science . . .




It's unnecessary to calls someone's beliefs silly. I suppose, if I had your attitude, I should edit the 2nd post. It currently reads:



cel4145 said:


> Since you posted here, you'll find someone that will champion the benefits of $200 USB cables.




I guess no one would have found it rude if I had said, 



cel4145 said:


> Since you posted here, you'll find some non-believers in science that will champion the benefits of $200 USB cables based on silly subjective listening tests.


----------



## x838nwy

Dude, re-read what you quoted. What i said was silly was the fact that amongst all the 'science' people who do not believe that cables make a difference only stopped at the hypothesis stage. Seriously, i've not edited it.


----------



## z3r0day

x838nwy said:


> Dude, re-read what you quoted. What i said was silly was the fact that amongst all the 'science' people who do not believe that cables make a difference only stopped at the hypothesis stage. Seriously, i've not edited it.


 
 Maybe if you put some evidences that clearly suggest that only USB cables themselves to be the cause of some kind of change in sound I might change my mind, otherwise, I could only depend on my existing knowledge.


----------



## cel4145

x838nwy said:


> Dude, re-read what you quoted. What i said was silly was the fact that amongst all the 'science' people who do not believe that cables make a difference only stopped at the hypothesis stage. Seriously, i've not edited it.




Go read the USB audio thread in the science forum: http://www.head-fi.org/t/554008/dont-get-why-audiophile-usb-cable-would-improve-sound-quality

A year and a half of discussion with 835 posts with plenty of evidence, there's no need for me (or anyone else) to fulfill your desire for acceptance that you feel that your USB audio cables provides better audio. It's been thoroughly discussed already. If you want to deny the science after you have digested it all, that's up to you. If you gain satisfaction out of your USB cables, good for you.


----------



## jimmers

Could I add "Creationism" into the mix?
 Or would that be _slightly _OT ?


----------



## x838nwy

Plenty of links have been posted plus a number of members have posted their experiences and impressions with regards to usb cables. I could recount my experiences but it seems that to a lot of people who can see for themselves without any costs will continue to flatly refuse any possibility.

So fine. If you choose to believe that if something cannot be measured, then it does not exist, that's fine by me. I have a different view.


----------



## z3r0day

x838nwy said:


> Plenty of links have been posted plus a number of members have posted their experiences and impressions with regards to usb cables. I could recount my experiences but it seems that to a lot of people who can see for themselves without any costs will continue to flatly refuse any possibility.
> 
> So fine. If you choose to believe that if something cannot be measured, then it does not exist, that's fine by me. I have a different view.


 
  
 If something cannot be measured, how could I know it exists in the first place?
  
 Give me one link that provide evidence that, isolates all other variables, shows that only a change in cable cause sonic differences, with specific explanation on how the difference occurred, then I would immediately change my mind.


----------



## x838nwy

cel4145 said:


> Go read the USB audio thread in the science forum: http://www.head-fi.org/t/554008/dont-get-why-audiophile-usb-cable-would-improve-sound-quality
> 
> A year and a half of discussion with 835 posts with plenty of evidence, there's no need for me (or anyone else) to fulfill your desire for acceptance that you feel that your USB audio cables provides better audio. It's been thoroughly discussed already. If you want to deny the science after you have digested it all, that's up to you. If you gain satisfaction out of your USB cables, good for you.




It doesn't seem too different from this thread. Only a relatively small number of posters quoting the same thing over and over then arriving at a false dichotomy that it's either placebo or a refusal to admit to a wasted purchase.

I'm not saying I understand why it makes a difference. Missing 1's and 0's are unlikely but a lot has been said about jitter and a few other factors which may contribute to what is heard. I was curious whether there is any difference. Now I am open to finding out what might have caused those differences. Placebo is a possibility, but more than one person has remarked on the change who did not know what I did to the system. Is that beyond statistical doubt? No. But it would be one hell of a placebo effect to take place while the subject was unaware about any change at all.


----------



## x838nwy

z3r0day said:


> If something cannot be measured, how could I know it exists in the first place?
> 
> Give me one link that provide evidence that, isolates all other variables, shows that only a change in cable cause sonic differences, with specific explanation on how the difference occurred, then I would immediately change my mind.




Detection and measurement are two different things. I can detect light in my room but i do not have the tools to measure its intensity or other properties, for example.

As for measurements, didn't 00940 posted something along those lines?

-- added text below --

Before anyone says that those measurements are for cables only, not the system.. This is what i posted elsewhere earlier:

As for how much the differences between cables manifest themselves at the speakers depends a lot on a number of factors. If you place a pair of headphones in a well and mic the sound from above the well, there's not going to be a lot of difference between headphones. I don't disagree that these differences (on cables) are may be due to simple factors like shielding and separation. But the bottom line is, there are differences among cables. Whether or not it is hearable is another matter.

Actually, this is where science comes in. Several of the seminars i've watched talk about limits of hearing. And how we are still learning about what we can or cannot hear. A lot of things remain without explanation - and this is from someone who design dac chips so i know he knows what he's talking about. While this is beside the point, what i'm saying is, somethings we cannot explain actually exist.


----------



## elmoe

x838nwy said:


> Plenty of links have been posted plus a number of members have posted their experiences and impressions with regards to usb cables. I could recount my experiences but it seems that to a lot of people who can see for themselves without any costs will continue to flatly refuse any possibility.
> 
> So fine. If you choose to believe that if something cannot be measured, then it does not exist, that's fine by me. I have a different view.


 
 Plenty of people have also posted about how buying a hundred dollar fuse made a big change to their DACs. Generally when you spend money on something, you want it to make thing better. In this hobby, for alot of things, it doesn't. It's not a hypothesis, it is proven fact not only because "science says so" but also because many MANY people have spent DECADES testing everything, wishing, praying, hoping science was wrong, yet they came to the conclusion it wasn't. I've read about alot of tests (I won't speak of their nature so as not to break forum rules), and every single test I've read (from literally dozens and dozens of them) had the same conclusion. That's hundreds if not thousands of people who THOUGHT they could differentiate good vs bad BEFORE who couldn't anymore at all, and very often picked the cheap gear as best sounding instead of the usual expensive one (from THEIR own system, expensive gear they were adamant made a BIG difference before). I think that simply speaks for itself.


----------



## 00940

z3r0day said:


> If something cannot be measured, how could I know it exists in the first place?
> 
> Give me one link that provide evidence that, isolates all other variables, shows that only a change in cable cause sonic differences, with specific explanation on how the difference occurred, then I would immediately change my mind.


 
  
 Something can be measured and not be audible 
  
 The article I quoted earlier (you'll have to buy the old Hifi News issue, it never went on the web) shows that differences exists. Different usb cables, all other things being kept equal, caused variations of a few hundred pS in jitter. Such variations can easily be explained in terms of power supply interactions. Even more so since one of the better performing cables had a ferrite ring on it.
  
 But a few hundred pS of differences aren't something you can prove to be audible.


----------



## x838nwy

elmoe

I think you're talking from experience and i can see where you're coming from. Fact of the matter is, sometimes it's obvious, sometimes not and sometimes there is no difference. The rest of the time is what you prefer.
I've wasted my fair share of money on tweaks. What i've found is that sometimes it's hard to say if there is anything in between a and b. But every now and again it's very clear.
For example right now i'm having a hard time choosing between the usb and the bridge connection on my pwd. I also cannot tell any difference between a couple of power cords i've tried on my amp. One of the power cords improved the mjolnir, however. But the usb cable difference is far from subtle. I'd say the change is bigger than other interconnects i've tried.
Lastly, it is an interesting point you make when you suggest that a few years down the road all this would show itself up as a folly. I don't know you and you don't me, but i'm not in this for flashiness or the ability to pat myself on the back for being able to hear the difference. And while i'm quite new to all this computer music, i'm not exactly new to hi-fi in general. Gyrodec, NAC72/135, Sonus Faber. That's where i'm from so i know mpingo discs when i see them. So i'm not the type to jump into the latest obscure mod/fad out there. Again i'd recommend people try it out. What's to lose?

@ 00940

I read somewhere that there are various types of jitter and the jury is still out on what is and what is not audible.


----------



## Lorspeaker

Plug in a cabledyne USB cable...
30days return policy.
For those itching to LISTEN instead of READING.


----------



## elmoe

x838nwy said:


> elmoe
> 
> I think you're talking from experience and i can see where you're coming from. Fact of the matter is, sometimes it's obvious, sometimes not and sometimes there is no difference. The rest of the time is what you prefer.
> I've wasted my fair share of money on tweaks. What i've found is that sometimes it's hard to say if there is anything in between a and b. But every now and again it's very clear.
> ...


 
  
 Well, more power to you if you believe there is an audible difference caused by the cable itself. I've done enough testing myself throughout the years to know that it is never the cable itself that changes the sound so long as the cables used are all properly built, and like you, I will base my opinion upon my own experiences (and of course, since they seem to be substantially backed up by the cold hard facts, I tend to lean even more towards them).
  
 As a last suggestion (and suggestion only), I would read this thread and the article quoted in the first post: http://www.head-fi.org/t/481415/what-if-the-audio-critic-is-completely-right-what-would-you-own


----------



## ab initio

If a power cord on tye mjolnir affected its performance, then you should contact Jason for a repair. Thier power supply sections are seriously over-designed to appeal to the strictest audiophile expectations and rule out audibility in even the worst-case-scenario.

http://schiit.com/products/mjolnir
The design specs are listed on their website. Their power amp section has more filter capacitence for this 8W amp than my 100W guitar amp!

Look at this thing!






I have huge respect for schitt that they show their board layout in detail. The design principles are solid.

Cheers


----------



## x838nwy

ab initio said:


> If a power cord on tye mjolnir affected its performance, then you should contact Jason for a repair. Thier power supply sections are seriously over-designed to appeal to the strictest audiophile expectations and rule out audibility in even the worst-case-scenario.
> 
> http://schiit.com/products/mjolnir
> The design specs are listed on their website. Their power amp section has more filter capacitence for this 8W amp than my 100W guitar amp!
> ...




I did, i asked him about fuses too. I tried the cord on the mjolnir cos in its intended home it did't do anything. So it just ended up there. I noticed a change but only after i changed cords to a stock one and felt something was amiss. A quick a/b confirmed it (well to my ears).

Jason said he doesn't think it's possible. I can't remember his exact words but generally he's not a guy who believes in cables. He does use Straightwire cables for his stuff though.

The fact that there was an improvement doesn't mean it was poorly designed. I don't know how you link the two factors together. The cable is a pangea 14se i think if you want to try it out.


----------



## elmoe

nvm i misread


----------



## Chris J

It's like déjà vu all over again.

This topic has been debated to death again and again and again.
What's the point in debating it again?
I don't see anyone convincing anyone of anything.

Someone posted a photo of a headphone amp with a heroic power supply.
The power supply rejects conducted noise by what mechanism?


----------



## cel4145

chris j said:


> It's like déjà vu all over again.
> 
> This topic has been debated to death again and again and again.
> What's the point in debating it again?




Too bad the thread can't have this as part of the title:


----------



## Chris J

cel4145 said:


> Too bad the thread can't have this as part of the title:




+1
Yeah, funny! 

But true!

I do enjoy reading about the technology, but I could do without the endless I'm right, you're wrong routine.


----------



## cel4145

chris j said:


> +1
> Yeah, funny!
> 
> But true!
> ...




And that's the trick. If people would not make it about the person by talking about other people, like x838nwy did, it's possible to have civil discourse and disagree. 

Maybe one day it will be confirmed that in some specific situation, that USB cables do help. Until then, I think people are better off saving up money for better headphones/speakers where everyone KNOWS that there is a good SQ benefit.


----------



## Chris J

cel4145 said:


> And that's the trick. If people would not make it about the person by talking about other people, like x838nwy did, it's possible to have civil discourse and disagree.
> 
> Maybe one day it will be confirmed that in some specific situation, that USB cables do help. Until then, I think people are better off saving up money for better headphones/speakers where everyone KNOWS that there is a good SQ benefit.




At the end of the day, it really comes down to:

"It's my money and I don't have to justify to anyone here how I spend it!"


----------



## Mambosenior

elmoe said:


> Most of the expensive cables I own I bought way back when I was still easily influenced and let placebo dictate what I heard. Years later, doing serious comparisons, I found no differences whatsoever. Now I just use em cause they look pretty connected to all my gear.
> 
> I also own a decent (read: expensive, although not TOO expensive) BNC to RCA digital cable, and a few (much cheaper) TOSlink optical cables. Guess what? They all sound the same.




Similar tale to tell here. I've kept the fancy (read: asinine expensive) cables as reminders of past foolishness. Those interested in chasing the dragon, go for it and spend away.


----------



## Lorspeaker

the earth was square...in the classroom, 
 until someone took a ship /spend the money n sailed.
 some turned back too soon...
 some shipwrecked,
 some found a great big continent..and called it the land of the free.
  






​


----------



## jimmers

lorspeaker said:


> the earth was square...in the classroom,
> until someone took a ship /spend the money n sailed.
> some turned back too soon...
> some shipwrecked,
> ...


 

 Do I even dare ask what you are talking about?
	

	
	
		
		

		
		
	


	



 ( apparently I did {at least I didn't follow a W with an F with a T between, terminated with an exclamation mark})


----------



## Chris J

jimmers said:


> Do I even dare ask what you are talking about?:blink:
> ( apparently I did {at least I didn't follow a W with an F with a T between, terminated with an exclamation mark})




Ummm, something about discovering America?
Some guy named Colombus.
Who was actually lost.
Or maybe not?
Signed,
Confused.


----------



## ab initio

chris j said:


> Someone posted a photo of a headphone amp with a heroic power supply.
> The power supply rejects conducted noise by what mechanism?





Google is your friend:

http://en.m.wikipedia.org/wiki/Power_supply_rejection_ratio


http://www.google.com/url?sa=t&source=web&cd=6&ved=0CDAQFjAF&url=http%3A%2F%2Fwww.designers-guide.org%2FDesign%2Fbypassing.pdf&ei=lBH_UrWFEoOBygG6r4CQAw&usg=AFQjCNFhMrTYPZBaS7VTuaInXTOxWs3_yw

http://en.m.wikipedia.org/wiki/Filter_capacitor

http://www.google.com/url?sa=t&source=web&cd=8&ved=0CEMQFjAH&url=http%3A%2F%2Fwww.analog.com%2Fstatic%2Fimported-files%2Ftutorials%2FMT-101.pdf&ei=hhP_UuiUA8KsyAGOzIHIDA&usg=AFQjCNH4P5gglHoreCDuUP2zfcTioFwCbA

http://www.techtransfer.com/resources/wiki/entry/2689/

Here are some background sources on how power supply design is used to reject noise

Cheers


----------



## jimmers

chris j said:


> Ummm, something about discovering America?
> Some guy named Colombus.


 
 Yeah,
 but they knew the earth was round and Columbus thought he could get to the east indies more quickly by heading west .
	

	
	
		
		

		
		
	


	



 That's why I was wondering what he was talking about; it was satirical, I guess .
 (I hope 
	

	
	
		
		

		
		
	


	




).
  
 And this has to do with USB cables?


----------



## 00940

Nada.
  
 Just like the surreal discussion of an amplifier power supply, mixing ripple, rectification noise and mains noise in a big soup and still having nothing to do with the issue at hand.


----------



## x838nwy

jimmers said:


> Yeah,
> but they knew the earth was round and Columbus thought he could get to the east indies more quickly by heading west .
> That's why I was wondering what he was talking about; it was satirical, I guess .
> (I hope  ).
> ...




Columbus got bored with the tweaks he could get in europe, so he went to see if anyone had and any power distributor or mpingo discs for sale in the us. It is the view of scholars that his sails were made from ers cloth.


----------



## x838nwy

Oh, here's something. Not exactly USB, but might be of interest: http://www.nordost.com/downloads/NewApproachesToAudioMeasurement.pdf


----------



## cel4145

jimmers said:


> And this has to do with USB cables?




Didn't you know? Just as with Columbus's voyage, a lot of brave cable fans died so that a few could discover the audio benefits of boutique USB cables? LOL

Personally, I think the better analogy is astronomer Fred Hoyle, who coined the term "Big Bang Theory," but never could accept it himself


----------



## Chris J

ab initio said:


> Google is your friend:
> 
> http://en.m.wikipedia.org/wiki/Power_supply_rejection_ratio
> 
> ...




Some of these links are good.
What I was very subtly getting at was the caps in the photo may be MASSIVE, but you also need to be able to reject and suppress very high frequency noise.
As some of your links point out, big electrolytic capacitors are not going to do it.
They are actually inductive at very high frequencies.


----------



## jimmers

cel4145 said:


> Personally, I think the better analogy is astronomer Fred Hoyle, who coined the term "Big Bang Theory,"..


 
 Was he one of the script writers?


----------



## ab initio

chris j said:


> Some of these links are good.
> What I was very subtly getting at was the caps in the photo may be MASSIVE, but you also need to be able to reject and suppress very high frequency noise.
> As some of your links point out, big electrolytic capacitors are not going to do it.
> They are actually inductive at very high frequencies.


 
  
 While what you are saying is technically correct, I think you are missing the point. The jumbo electrolytic caps are very effective at filtering out noise in the audio-frequency range (< 20 kHz). The effect you mention regarding inductance at high frequency isn't relevant until you approach the megahertz range (See the analog devices tutorial I linked above). The high frequencies are rejected using small (picofarad--microfarad range) ceramic or tantalum capacitors placed in close proximity to the active devices in the circuit. Go back and take a careful look at the Schiit circuit and you'll see numerous small capacitors near the active devices. These reject the high frequency noise and suppress high frequency (MHz, inaudible) ringing.
  
 The reason I pointed out the large filter cap's is because 1) they're huge and laypeople can even find them in the picture and 2) they reject the noise in the power line at the audible frequencies.
  
 Also, this is a little off topic in a thread about USB-standard passing cables deteriorating sound  in USB devices. I'm saying that 1) it's highly unlikely for a usb cable to have an audible affect and 2) if it does, it's not the cable's fault; rather, the usb device or computer usb controller is a piece of junk.
  
 A well-designed modern asynchronous usb dac can be had for under $100 and the choice of usb cable, as long as the cable is standard compliant, has no affect on the resulting sound. The data is delivered error-free and the power is supplied.
  
 Cheers


----------



## Chris J

ab initio said:


> While what you are saying is technically correct, I think you are missing the point. The jumbo electrolytic caps are very effective at filtering out noise in the audio-frequency range (< 20 kHz). The effect you mention regarding inductance at high frequency isn't relevant until you approach the megahertz range (See the analog devices tutorial I linked above). The high frequencies are rejected using small (picofarad--microfarad range) ceramic or tantalum capacitors placed in close proximity to the active devices in the circuit. Go back and take a careful look at the Schiit circuit and you'll see numerous small capacitors near the active devices. These reject the high frequency noise and suppress high frequency (MHz, inaudible) ringing.
> 
> The reason I pointed out the large filter cap's is because 1) they're huge and laypeople can even find them in the picture and 2) they reject the noise in the power line at the audible frequencies.
> 
> ...




I can see where this is going.
No thank you.
Regards,
Chris


----------



## CJs06

ab initio said:


> Also, this is a little off topic in a thread about USB-standard passing cables deteriorating sound  in USB devices. I'm saying that 1) it's highly unlikely for a usb cable to have an audible affect and 2) if it does, it's not the cable's fault; rather, the usb device or computer usb controller is a piece of junk.
> 
> A well-designed modern asynchronous usb dac can be had for under $100 and the choice of usb cable, as long as the cable is standard compliant, has no affect on the resulting sound. The data is delivered error-free and the power is supplied.


 
  
 My experience confirms what you are saying. I used to use an old 3ft USB A cable to connect my PC to my Modi and after a while, I would get lots of jitter to the point where the device wouldn't be recognized by Windows anymore. I swapped out the cable for a new shorter USB A cable and voila, problem solved, all the 1s and 0s made it to the DAC without error.


----------



## realkandar

i'm using my usb audiophile cable make from e-sata 3 GB. the sound was excellent.


----------



## ampair

realkandar said:


> i'm using my usb audiophile cable make from e-sata 3 GB. the sound was excellent.


 
 nice job, i like it!
  
 but i'm sure that a double-shielded silver plated ofc sata6g cable, handcrafted by little audiophile virgin fairies, would sound muuuuuuuch better


----------



## realkandar

ampair said:


> nice job, i like it!
> 
> but i'm sure that a double-shielded silver plated ofc sata6g cable, handcrafted by little audiophile virgin fairies, would sound muuuuuuuch better


 
 thanks you sir.
 yes...more much better is with sata 6 GB. and i has craft with all of sata, started with sata 1,5 GB U/ 6 GB. it's amazing. and who know..if sata can we modified became audio cable. all of my audio stuff using sata cable, cause its has good spec.


----------



## ab initio

realkandar said:


> thanks you sir.
> yes...more much better is with sata 6 GB. and i has craft with all of sata, started with sata 1,5 GB U/ 6 GB. it's amazing. and who know..if sata can we modified became audio cable. all of my audio stuff using sata cable, cause its has good spec.


 
  
 What on earth are you talking about? You have "audiophile" cables for your hard disk?
  
 I am seriously confuzzled right now. 
	

	
	
		
		

		
		
	


	



  
  
 Cheers


----------



## realkandar

ab initio said:


> What on earth are you talking about? You have "audiophile" cables for your hard disk?
> 
> I am seriously confuzzled right now.
> 
> ...


 
 hai..   cheers.
 i mean, i have usb audiophile cable made from SATA cable. really..it's work.
 i'm modified the head of cable become usb A-B.


----------



## zool

I'm no expert. But wouldn't the +5VCC cable ideally be separately shielded from data+/- and gnd? To minimize jitter or interference.


----------



## zool

The reason why I'm asking is as a cable maker myself I would think that the thin Data +, data - wires would be subject to some noise from the +5V cable that it's tightly wrapped around them. Almost no standard USB cable have them separately shielded but allot of "hifi"-based" USB chords do. From what I understand.. When transferring files for example, this is not as sensitive because of the USB protocol that uses various methods like CRC check sums to find errors and either correct them or have that packet of data resent. And in the end this will not be very noticeable when transferring files etc. But with audio it is not that simple. With audio the CRC check sums methods etc causes jitter which can be audible from what I understand.
  
 This is just of course my speculation. I have not tested enough hifi USB cables to be able to say if they made any difference or not. But I was going to build one and I started thinking about this... Anyway, kind of old thread. Maybe no one cares about this any more .


----------



## ab initio

zool said:


> With audio the CRC check sums methods etc causes jitter which can be audible from what I understand.




Why would that be the case? There is no reason to expect that. Either a data packet arrives sufficiently intact that the original data is completely derived from the 10/8 encoding, else the whole packet is dropped. Nowhere in there is "jitter" added. Especially since any modern Asynchronous DAC reclocks the audio anyway. 

Cheers


----------



## zool

ab initio said:


> Why would that be the case? There is no reason to expect that. Either a data packet arrives sufficiently intact that the original data is completely derived from the 10/8 encoding, else the whole packet is dropped. Nowhere in there is "jitter" added. Especially since any modern Asynchronous DAC reclocks the audio anyway.
> 
> Cheers


 
 What is the difference between digital signal sent through usb or digital sent through spdif or AES/EBU? They are all digital 1's and 0's, correct? And if those other standards are subject to noise and jitter what makes usb so magical that it totally is immune to this? A good article to read about what jitter actually is and what effect it has -> http://www.stereophile.com/reference/1093jitter/.
  
 I'm not trying to start a flame war or any thing. I just want it explained to me what makes usb so different from other digital wires used in audio. And why it would not be subject to noise and interference caused by electrical wires for example.


----------



## ab initio

zool said:


> What is the difference between digital signal sent through usb or digital sent through spdif or AES/EBU? They are all digital 1's and 0's, correct? And if those other standards are subject to noise and jitter what makes usb so magical that it totally is immune to this? A good article to read about what jitter actually is and what effect it has -> http://www.stereophile.com/reference/1093jitter/.
> 
> I'm not trying to start a flame war or any thing. I just want it explained to me what makes usb so different from other digital wires used in audio. And why it would not be subject to noise and interference caused by electrical wires for example.




Spdif is different from usb. Usb is packet based. Timing is set by the receiving device. Spdif has to encode clocks within the data.

See Jason Stoddard 's post in the schiit story thread. He just discussed it today.
http://www.head-fi.org/t/701900/schiit-happened-the-story-of-the-worlds-most-improbable-start-up/1185#post_10605619

The article you linked on jitter is not a very good source. It does nothing to relate tye amplitude of jitter to levels required for audible degradation. The 300ps of jitter they are discussing is irrelevant to audio.

Cheers

Ps. If you want to discuss technical questions, the sound science forum is an excellent place to ask. The folks there are interested in understanding how audio works inside and out and you can freely discuss the scientific evidence there


----------



## zool

ab initio said:


> Spdif is different from usb. Usb is packet based. Timing is set by the receiving device. Spdif has to encode clocks within the data.
> 
> See Jason Stoddard 's post in the schiit story thread. He just discussed it today.
> 
> ...


 
 LOL, seemed like a pretty good source to me. I'll do some reading about this on the schiit story thread. Thanks m8, always eager to learn new stuff. Well new for me anyway .


----------



## ab initio

zool said:


> LOL, seemed like a pretty good source to me. I'll do some reading about this on the schiit story thread. Thanks m8, always eager to learn new stuff. Well new for me anyway .




I really enjoy the schiit narrative 

Cheers


----------



## zool

Well, the reason I wanted to make one from the start was I wanted gold plated connectors. I noticed that my DAC would loose signal from time to time when I was fiddling around with the wires at the back of my computer. The standard usb connector seemed very sensitive which is kind of weird because I've never noticed this with external usb hdd's or any other usb based unit for that matter. This has not ever been a issue except with the DAC. When I was checking what it would cost to actually make one I came to the conclusion that it would cost the same or more than just buying a supra usb 2.0 cable for $40 (3 meters). So that's what I think I'll do. See if it solves the problem.


----------



## ab initio

You want to make sure all of your cables fit snuggly into their sockets. If you're experiencing dropouts when you fiddle around your computer, it seems like you have a bad connection. 

Cheers


----------



## zool

ab initio said:


> You want to make sure all of your cables fit snuggly into their sockets. If you're experiencing dropouts when you fiddle around your computer, it seems like you have a bad connection.
> 
> Cheers


 
 Well, the motherboard is brand new, only had it for like 2 months maybe. So the sockets have not been used allot.
  
 I've used the same exact cable for a ubs hub and never had any drop outs there. Just seems like the DAC is extra sensitive when it comes to signal.


----------



## USAudio

Thought some of you here might find this interesting:
 http://archimago.blogspot.ca/2013/04/measurements-usb-cables-for-dacs.html
  
 (I posted this in another thread but it was deleted ... so re-posting here)


----------



## Tablix

usaudio said:


> Thought some of you here might find this interesting:
> http://archimago.blogspot.ca/2013/04/measurements-usb-cables-for-dacs.html
> 
> (I posted this in another thread but it was deleted ... so re-posting here)


 
 Sad fact is you cant persuade some people with science, data, or any other form of empirical evidence....people will spend their money how they like regardless.  Its entirely possible that temperature difference or humidity can affect sound quality with speaker set-ups yet people dont investigate that but still spend a few hundred bucks on silver cables. 
  
 Probably get a better response in the sound science forums, the geeks love this sort of data


----------



## trentrosa

Ideally, in my mind a digital cable should exactly transfer data, no boutique needed. I also believe an analog cable only influences the sound when introducing capacitance or external noise due to poor shielding. A conductor is a conductor. What do you guys think?


----------



## hmorneau

I use audiophile cable for my printer, it print the text shaper and make the picture cleaner too, the colour are more realistic and vivid. With a $200 the colour are not that nice, but with a $500 cable it's really better.
  
 /s


----------



## jimmers

trentrosa said:


> Ideally, in my mind a digital cable should exactly transfer data, no boutique needed. I also believe an analog cable only influences the sound when introducing capacitance or external noise due to poor shielding. A conductor is a conductor. What do you guys think?


 

 Nah, it's waaay more complicated than that!!
 I have read so in many, many places, but no one's been able to say in what way 
	

	
	
		
		

		
			




  
 (living in the age of science...  with the Emperor's new clothes)


----------



## hmorneau

Well, if numeric was not numeric (and it was sort of like analog) we would be screwed up at this age of Internet where everybody transfer and copy stuff all the time. 
  
 If you plug a USB drive to the end of a usb cable, and copie a music file back and forth a couple of time, I hope nobody will believe that the file will change. But if you stream that same file to a DAC, now the story change, why? Probably because it would sound foolish to report no change after spending that much on a cable. Also notice that the more expensive is the cable, the better it sound. An other funny fact, it's that it always improve the sound, it never do worst then the cheap $2 cable. Also when you read the technical specs of those expensive cable, it's really interesting to see how they can use complicated word to express simple stuff as plastic.
  
 For those who really hear a difference, it's because there is actually one. Well, not physically, but in your head yes. It's what we call placebo effect, and that effect is fully recognized by the science. That's why the pharmaceutical industry must do comparison to placebo. When we expect something to happen, there is chance that it will happen. So those who say, not it's really there, yes it is. Lot of people get cured that way, so could it simply improve the sound, sure.There is an interesting article here http://www.nytimes.com/.. Basically they show that he placebo effect doesn't apply just to pills, but to surgery intervention as well. 
  
 Now why I'm concern about those cable sounding better thing, well, if an expensive cable sound better, then there is high chance that a more expensive amp may be perceived wrongly in some case to sound better as well simply because it's more expensive. So the placebo effect probably have effect on amp, headphone and other stuff. So at the end of the day it's hard to make a good decision based only on what people report. 
  
 Maybe it would be cool to create profile category on head-fi. You ask a couple of simple questions, like do you think cable change the sound in your setup. Then you sort those people in a category where you identify them as being more influenced by the placebo effect. Other who don't, you put them in an other category. So that way we could maybe create a scale of subjectiveness and objectiveness depending of the type of person you are. Then people reading post here could trust more a review from someone who have a "subjectivity" profile similar to them. That way everybody would be happy and at the end people would probably buy equipment that are better for their taste and those cable lover will continue to enjoy their great sound.


----------



## jimmers

> Also when you read the technical specs of those expensive cable, it's really interesting to see how they can use complicated word to express simple stuff as plastic.


 
 If you think "plastic" is simple, you probably shouldn't be commenting on it.
 Although the great variations in "plastic" parameters are unlikely to have any noticeable effect at audio frequencies or USB data rates (unless you go a long way out of your way to find something unsuitable).


----------



## Thad-E-Ginathom

hmorneau said:


> If you plug a USB drive to the end of a usb cable, and copie a music file back and forth a couple of time, I hope nobody will believe that the file will change. But if you stream that same file to a DAC, now the story change, why?


 
  
 You will see from my signature that I am very much inclined to agree with you.
  
 People may say, though, that the copying of a file by  USB is not the same as sending that data to to a DAC; that there is a USB _Audio_ Protocol. l don't know the answer to that. I'm sure there is one?
  


jimmers said:


> If you think "plastic" is simple, you probably shouldn't be commenting on it.
> Although the great variations in "plastic" parameters are unlikely to have any noticeable effect at audio frequencies or USB data rates (unless you go a long way out of your way to find something unsuitable).


 
  
 I used to sail with a retired plastics scientist. His boat was wooden. He said he felt safer in a wooden boat because he knew very little about wood, but he knew too much about plastic to feel safe!


----------



## groovyd

the only improvement a 'better' cable 'might' make is in the ability to deliver clean bus power for dacs that might not be properly power isolated or use the usb power bus as a reference voltage directly.  but then again i highly doubt any decent dac designer worth their reputation would ever use the usb bus power directly without serious re-regulation and filtering in the middle. money better spent would be some sort of usb bus power filter.


----------



## hmorneau

jimmers said:


> If you think "plastic" is simple, you probably shouldn't be commenting on it.
> Although the great variations in "plastic" parameters are unlikely to have any noticeable effect at audio frequencies or USB data rates (unless you go a long way out of your way to find something unsuitable).


 
  
 They will say something generic like "shielded with organic polymers of high molecular mass" which is what most plastic are made of. I'm not saying that there is only one sort of plastic, I'm just saying that they try really hard to find complex word that explain simple concept.


----------



## hmorneau

thad-e-ginathom said:


> You will see from my signature that I am very much inclined to agree with you.
> 
> People may say, though, that the copying of a file by  USB is not the same as sending that data to to a DAC; that there is a USB _Audio_ Protocol. l don't know the answer to that. I'm sure there is one?
> 
> ...


 
 If we have protocol to transfer file without any error, there is no reason not to have one to transfer numeric audio without error as well. If the protocol was broken, then we would simply have to fix it. Buying expensive cable is not the way of doing that.
  
 From wikipedia: "Unlike analog signals, digital data can be transmitted, manipulated, and stored without degradation, albeit with more complex equipment. But a DAC is needed to convert the digital signal to analog to drive an earphone or loudspeaker amplifier in order to produce sound (analog air pressure waves)."
  
Basically as long as it's digital nothing will change, I have a pretty good DAC (Wyred 4 sound DAC2) and even with a dollar store usb cable I don't hear any noise in the background. The most important part is the connection once the digital signal have been converted to analog. Personally I use balanced cable between my DAC and my amp, that way I have no noise at all. With RCA I can get some interference (background noise). Personally I use digiflex cable touring series, they are made with neutrik connector.
  

  
 $13 for a 3 feet and there are made to last.


----------



## hmorneau

groovyd said:


> the only improvement a 'better' cable 'might' make is in the ability to deliver clean bus power for dacs that might not be properly power isolated or use the usb power bus as a reference voltage directly.  but then again i highly doubt any decent dac designer worth their reputation would ever use the usb bus power directly without serious re-regulation and filtering in the middle. money better spent would be some sort of usb bus power filter.


 
 Just open your computer case, you will see how many cable without proper shield are in there, your power will be already dirty before it even leaves your usb port. I don't think the part going outside the case with make much of a difference. 
  
 I'm sure changing to a different computer would have a much bigger impact then the usb cable (if your DAC is crappy and grab interference from the usb interface).


----------



## groovyd

hmorneau said:


> Just open your computer case, you will see how many cable without proper shield are in there, your power will be already dirty before it even leaves your usb port. I don't think the part going outside the case with make much of a difference.
> 
> I'm sure changing to a different computer would have a much bigger impact then the usb cable (if your DAC is crappy and grab interference from the usb interface).


 

 my point being more that the 'only' difference could be in the delivery of bus power as the signal part is identical no matter what the cable. digital is digital.  for dacs that tie into the usb bus power directly or use it as a reference you might hear a difference between two cables but sure usb power is ridiculously noisey already.


----------



## Chris J

hmorneau said:


> Just open your computer case, you will see how many cable without proper shield are in there, your power will be already dirty before it even leaves your usb port. I don't think the part going outside the case with make much of a difference.
> 
> I'm sure changing to a different computer would have a much bigger impact then the usb cable (if your DAC is crappy and grab interference from the usb interface).




Good point.
People often say that USB Cable A may be better than Cable B because Cable A has better shielding.
Or is the USB cable shielded to protect the signal from noise radiated by the poorly shielded computer?
Just thinking out loud....


----------



## hmorneau

chris j said:


> Good point.
> People often say that USB Cable A may be better than Cable B because Cable A has better shielding.
> Or is the USB cable shielded to protect the signal from noise radiated by the poorly shielded computer?
> Just thinking out loud....


 
 The problem is that the usb power doesn't start at the usb port, but at the PSU, so once it get to the usb it's already full of noise. It's like getting in a home with your boots full of dirty and you ask if vacuuming your floor would prevent your boots from getting dirty, they already are!


----------



## groovyd

hmorneau said:


> The problem is that the usb power doesn't start at the usb port, but at the PSU, so once it get to the usb it's already full of noise. It's like getting in a home with your boots full of dirty and you ask if vacuuming your floor would prevent your boots from getting dirty, they already are!


 

 yeah, well it is what it is... like i said a power filter would be a better investment then a better cable.


----------



## Lorspeaker

This cabledyne USB cable is amazing...
That rustle in the bush as the samurais come charging thru .. 
What a treat


----------



## BirdManOfCT

x838nwy said:


> Detection and measurement are two different things. I can detect light in my room but i do not have the tools to measure its intensity or other properties, for example.
> 
> As for measurements, didn't 00940 posted something along those lines?
> 
> ...


 

 I'm tired of most no-difference types. It started a long time ago when I was scoffed. And then proven right 10-20 years later. Suddenly, they're preaching a different tune and acting like THEY were the first to recognize it. Nope. And they weren't even the first to measure it. I had measurements, which were dismissed because it "wasn't possible".
  
 Sounds like that old saying that those who say it can't be done should get out of the way of those already doing it.


----------



## BirdManOfCT

cel4145 said:


> Too bad the thread can't have this as part of the title:


 

 LOL


----------



## BirdManOfCT

tablix said:


> Sad fact is you cant persuade some people with science, data, or any other form of empirical evidence....people will spend their money how they like regardless.  Its entirely possible that temperature difference or humidity can affect sound quality with speaker set-ups yet people dont investigate that but still spend a few hundred bucks on silver cables.
> 
> Probably get a better response in the sound science forums, the geeks love this sort of data


 

 You can't evaluate a system only by its components alone. Kinda like saying the fuel line from gas tank to engine is digital -- either it works or it doesn't. Therefore, all gas-fueled cars are the same.


----------



## BirdManOfCT

groovyd said:


> the only improvement a 'better' cable 'might' make is in the ability to deliver clean bus power for dacs that might not be properly power isolated or use the usb power bus as a reference voltage directly.  but then again i highly doubt any decent dac designer worth their reputation would ever use the usb bus power directly without serious re-regulation and filtering in the middle. money better spent would be some sort of usb bus power filter.


 

 So, seems obvious that in some possible situations there could be an audible difference? And not just placebo effect?


----------



## Head Injury

birdmanofct said:


> So, seems obvious that in some possible situations there could be an audible difference? And not just placebo effect?


 

 In some rare, specific cases yes, I can see USB cables with a specific design helping, and same with analog cables.
  
 The effects, however, will have no correlation to price and little to do with the "innovations" audiophile cables claim to feature. And more often than not the problems will manifest in very obvious ways, like audible noise and dropouts. Not audiophile concepts like "air", "texture", "PRaT", etc.


----------



## domer

I actually have a bit of experience with this subject and because of that I want to quickly jump in here.  It is possible (ok, likely) that this same comment was already posted like 20 times, but I could only make it to someone copy/pasting an interview with some "expert" from Audioquest (yeah, the company that makes products like this) before giving up.
  
 Of course digital signals are simply analog square waves, and they are subject to the same damage and distortion as any other analog signal.  No argument from me on that!  The difference is that for a digital signal the 'damage' and 'distortion' don't actually affect the end result unless there is an event of biblical proportions causing said damage.  Like let's say you were listening to music in a running microwave oven.  That would do it probably.  Is your USB cable resting on top of a kicking subwoofer?  If so the subwoofer is probably also affecting the sound, but the signal might be wonky too.  You would not believe how bad a square wave can look while still transferring one billion bits with zero errors.  Anyone who claims they can hear a difference between a Monoprice USB cable and a $200 one is either a) lying, b) delusional, or c) the changes are coming from some external factor having nothing directly to do with the cable.  Like the background noise changed while you were exchanging cables, or an analog connector got bumped while putting the headphones on.  Those are the only options, now go buy this and donate $195 to the charity of your choice.


----------



## Lorspeaker

http://www.cabledyne.com/usb-cable.html
  
 y waste good money on a 5buckcable


----------



## HI-BIT

I agree, and one can also "waste good money" on $600 USB cables. The Cabledyne is sonically excellent and a bargain IMO.


----------



## hmorneau

domer said:


> I actually have a bit of experience with this subject and because of that I want to quickly jump in here.  It is possible (ok, likely) that this same comment was already posted like 20 times, but I could only make it to someone copy/pasting an interview with some "expert" from Audioquest (yeah, the company that makes products like this) before giving up.
> 
> Of course digital signals are simply analog square waves, and they are subject to the same damage and distortion as any other analog signal.  No argument from me on that!  The difference is that for a digital signal the 'damage' and 'distortion' don't actually affect the end result unless there is an event of biblical proportions causing said damage.  Like let's say you were listening to music in a running microwave oven.  That would do it probably.  Is your USB cable resting on top of a kicking subwoofer?  If so the subwoofer is probably also affecting the sound, but the signal might be wonky too.  You would not believe how bad a square wave can look while still transferring one billion bits with zero errors.  Anyone who claims they can hear a difference between a Monoprice USB cable and a $200 one is either a) lying, b) delusional, or c) the changes are coming from some external factor having nothing directly to do with the cable.  Like the background noise changed while you were exchanging cables, or an analog connector got bumped while putting the headphones on.  Those are the only options, now go buy this and donate $195 to the charity of your choice.


 
 If the quality of the cable were indeed making a difference on the digital cable all the internet would be in trouble. No body believe that when you download a high quality track from a server on the internet that the network cable quality make any difference in the sound, but something magical happens when the same data transfert between the computer and the dac. I don't know what is it, but suddenly for that last few inch the rules of how digital data travel change. 
  


> Originally Posted by *x838nwy*
> 
> 
> 
> ...


 
 You may not have the tools, but it doesn't mean they don't exist. 
  
 From wikipedia:
Light is measured with two main alternative sets of units: radiometry consists of measurements of light power at all wavelengths, while photometry measures light with wavelength weighted with respect to a standardised model of human brightness perception. Photometry is useful, for example, to quantify Illumination (lighting) intended for human use. 
  
 Ho well, I give up. Buy all the cables you want, in fact I should start selling some.


----------



## x838nwy

hmorneau said:


> You may not have the tools, but it doesn't mean they don't exist.
> 
> From wikipedia:
> Light is measured with two main alternative sets of units: radiometry consists of measurements of light power at all wavelengths, while photometry measures light with wavelength weighted with respect to a standardised model of human brightness perception. Photometry is useful, for example, to quantify Illumination (lighting) intended for human use.
> ...


 
  
 I think you misunderstood my post. I wrote of detection and measurement to explain that just because I lack to tools to measure something, it does not mean I cannot detect its presence. I'm quite aware that several attributes of light or more generally - radio magnetic waves - can be measured. I was simply saying that just because I do not have any of these tools of measurement to hand does not mean I cannot say with any certainty that my room is lit. Just because I cannot currently measure the intensity or wavelength of the visible light content falling on my retina does not invalidate my statement that this room is lit with, say, a green light.
  
 Obviously if there are measurements of what I am seeing then my claims can be verified and science dictates that evidence overrules whatever my opinions or perceptions may be, but to demand that anyone* who claims to hear a difference that they produce a comprehensive set of measurements is a little silly.
  
 * - anyone without commercial interest in sales of these cables.


----------



## BirdManOfCT

x838nwy said:


> I think you misunderstood my post. I wrote of detection and measurement to explain that just because I lack to tools to measure something, it does not mean I cannot detect its presence. I'm quite aware that several attributes of light or more generally - radio magnetic waves - can be measured. I was simply saying that just because I do not have any of these tools of measurement to hand does not mean I cannot say with any certainty that my room is lit. Just because I cannot currently measure the intensity or wavelength of the visible light content falling on my retina does not invalidate my statement that this room is lit with, say, a green light.
> 
> Obviously if there are measurements of what I am seeing then my claims can be verified and science dictates that evidence overrules whatever my opinions or perceptions may be, but to demand that anyone* who claims to hear a difference that they produce a comprehensive set of measurements is a little silly.
> 
> * - anyone without commercial interest in sales of these cables.


 

 That makes too much sense. Therefore, your post is disqualified.


----------



## sANDEKERU

You need an audiophile USB controller (you will also need to shield it using tinfoil lined with something that will insulate the pcb) that only runs your dac so that no other usb devices connected to your computer can interfere with your dac.


----------



## hmorneau

x838nwy said:


> I think you misunderstood my post. I wrote of detection and measurement to explain that just because I lack to tools to measure something, it does not mean I cannot detect its presence. I'm quite aware that several attributes of light or more generally - radio magnetic waves - can be measured. I was simply saying that just because I do not have any of these tools of measurement to hand does not mean I cannot say with any certainty that my room is lit. Just because I cannot currently measure the intensity or wavelength of the visible light content falling on my retina does not invalidate my statement that this room is lit with, say, a green light.
> 
> Obviously if there are measurements of what I am seeing then my claims can be verified and science dictates that evidence overrules whatever my opinions or perceptions may be, but to demand that anyone* who claims to hear a difference that they produce a comprehensive set of measurements is a little silly.
> 
> * - anyone without commercial interest in sales of these cables.


 
 I agree that I can't argue with that, read about the "Argument from ignorance".
  
"Arguments that appeal to ignorance rely _merely_ on the fact that the veracity of the proposition is not disproven to arrive at a definite conclusion. These arguments fail to appreciate that the limits of one's understanding or certainty do not change what is true. They do not _inform_ upon reality. "
  
For more info: http://en.wikipedia.org/wiki/Argument_from_ignorance


----------



## x838nwy

hmorneau said:


> I agree that I can't argue with that, read about the "Argument from ignorance".
> 
> "Arguments that appeal to ignorance rely _merely_ on the fact that the veracity of the proposition is not disproven to arrive at a definite conclusion. These arguments fail to appreciate that the limits of one's understanding or certainty do not change what is true. They do not _inform_ upon reality. "
> 
> For more info: http://en.wikipedia.org/wiki/Argument_from_ignorance


 
  
 Thank you for pointing that out and it is useful to watch out for such arguments in future discussions of this kind (and of cables in general). However, I don't think it applies in the case of which I wrote.
  
 "I observe [X] when I do [Y]" is not an argument but a statement of observation. An argument from ignorance would be to say that "I observe [X] when I do [Y]_ because of_ [A]. I cannot prove that it is _not_ [A], therefore it _is_."
  
 As an example, before the days of Newton, a person can truthfully say that when he lets go of an unsupported object, it falls to the ground. This is a correct observation because the object does certainly fall to the ground. If the person were to state that said object falls to the ground at a constant velocity, this would be an incorrect observation as it disagrees with other precise and measured observations. It's still however not an argument. Now if the person were to claim that objects fall and he/she thinks it is because the earth is full of little holes and it just kindda sucks things down this is now an argument or rather this proposal is open for argument. It still, unfortunately, does not make it an appeal to ignorance as it still need to go further to say that "because it cannot be proven that the earth doesn't suck through little holes, therefore it must" to be come such an appeal/argument.
  
 So saying cable [C] sounds better than cable [D] is _not_ an argument from ignorance. What I was writing about was that if someone makes such a claim, it is not productive to ask him/her for measurements or "proof" or whatever because the tools to obtain the "proof" is normally not within reach of the person reporting the observation. To further go on to claim that if no "proof" can be given for the observation then the observation must be somehow false is equally silly and is entering the realm of being an appeal to ignorance.
  
 Before we go further, I agree that a statement of observation does not and cannot make a very strong case for anything. But that is sadly a limitation a great number of us face - we do not have the tools or the expertise to offer explanations of what we observe so there is simply not enough material for a proper argument among typical** members of this forum. In fact, most of us do not even have the tools to verify our observations except for our ears and perceptions. And this is really there we hit a bit of am imps-ass. Some say they do, some say they do not but the majority cannot offer a great deal of explanation or verification of their observation.
  
 This is were I think the more expert and learned members and the MOT's can really help - and thankfully they have offered information and measurements to support both views. It is clear that more evidence suggests that there is no difference between USB cables (as long as they are to spec. etc.) that will result in a different output from the DAC. But there are some quite prominent figures in the industry who do not make or sell cables who claim they do hear a difference. So yes, if one were to conclude based on currently available information, one would have to conclude that USB cables make no difference. But then again, a lot of very smart people once claimed "perfect sound forever" 
  
 Actually, come to think of it, "audiophile USB cables make no difference - there is no proof that they do, therefore they do not" is actually an argument from ignorance. Odd that.
  
 ** - members like myself who just use their (untrained) ears and may be an amount of reading on the subject.


----------



## hmorneau

x838nwy said:


> Actually, come to think of it, "audiophile USB cables make no difference - there is no proof that they do, therefore they do not" is actually an argument from ignorance. Odd that.


 
"One must always remember that the burden of proof is on the person making a contentious claim."


----------



## x838nwy

hmorneau said:


> "One must always remember that the burden of proof is on the person making a contentious claim."


 
  
 A feeling shared by many. But the contentiousness of a claim is subjective. Talk to a creationist about evolution and you'll find that they think the whole evolving from apes thing not just contentious but simply bat-$hit crazy. But to scientists, the idea of a creator putting fossils in the ground to test our faith is a stretch of the imagination to say the least. To someone one who hears (or believes they hear) the difference, a claim otherwise is contentious. To a person who hears none, a claim to the contrary is more contentious.


----------



## hmorneau

x838nwy said:


> A feeling shared by many. But the contentiousness of a claim is subjective. Talk to a creationist about evolution and you'll find that they think the whole evolving from apes thing not just contentious but simply bat-$hit crazy. But to scientists, the idea of a creator putting fossils in the ground to test our faith is a stretch of the imagination to say the least. To someone one who hears (or believes they hear) the difference, a claim otherwise is contentious. To a person who hears none, a claim to the contrary is more contentious.


 
 The science (backing the evolution theory) says that there is no loss of sound quality when it's digital. Those who hear the difference I let you guess which category they belong according to your explanation.


----------



## x838nwy

hmorneau said:


> The science (backing the evolution theory) says that there is no loss of sound quality when it's digital. Those who hear the difference I let you guess which category they belong according to your explanation.


 
  
 Lolz. Admittedly when it comes to audiophile cables, I'm a bit of a Fox Mulder


----------



## valtopps

wow still people don't believe there a difference in sound with usb cables, wow! again.
 I don't know the how or why but I can hear it. ive went with a belkin gold usb and it sounded good. I decided to try a pangea usb w/ 4% silver a few months ago and wasn't thinking I was going to here anything, wow I said to my self that's sound so good, better then the belkin.
 a week ago I bought the pangea pure silver usb again wow! I heard more detail clearer highs.
  
 the people saying theres no difference must not have high end equipment or never tried a good usb cable.


----------



## domer

valtopps said:


> wow still people don't believe there a difference in sound with usb cables, wow! again.
> I don't know the how or why but I can hear it. ive went with a belkin gold usb and it sounded good. I decided to try a pangea usb w/ 4% silver a few months ago and wasn't thinking I was going to here anything, wow I said to my self that's sound so good, better then the belkin.
> a week ago I bought the pangea pure silver usb again wow! I heard more detail clearer highs.
> 
> the people saying theres no difference must not have high end equipment or never tried a good usb cable.


 
  
 You, sir, fall under category 'B'.  See my earlier post for more details.


----------



## Lorspeaker

... bravo for the B club      bad for the wallet..


----------



## valtopps

lmao like I said before try before you open your mouth or buy some good equipment before testing.  im not going to argue over this, I spent a whole night testing all three cables and I can tell you what cable was plugged into my dac without looking. please don't respond to this post I don't care what you have to say.


----------



## domer

If you really don't care then hey, don't reply!  Let me ask this: Do you care about the cable that transfers music to your digital music player?  (Maybe it's your phone, or Fiio X5, or whatever.)  I'm mostly just curious.  I mean, the correct answer is no, but a yes would be no more crazy than the rest of this thread, so I'm ready for anything.  You tell me.


----------



## bfreedma

valtopps said:


> lmao like I said before try before you open your mouth or buy some good equipment before testing.  im not going to argue over this, I spent a whole night testing all three cables and I can tell you what cable was plugged into my dac without looking. please don't respond to this post I don't care what you have to say.




Unsubstantiated anecdotal evidence supported by vigorous hand waving or known science supported by actual measurements indicating no possible audible difference. What to believe.....


----------



## hmorneau

valtopps said:


> wow still people don't believe there a difference in sound with usb cables, wow! again.
> I don't know the how or why but I can hear it. ive went with a belkin gold usb and it sounded good. I decided to try a pangea usb w/ 4% silver a few months ago and wasn't thinking I was going to here anything, wow I said to my self that's sound so good, better then the belkin.
> a week ago I bought the pangea pure silver usb again wow! I heard more detail clearer highs.
> 
> the people saying theres no difference must not have high end equipment or never tried a good usb cable.


 
 I do believe that you ear a difference, that's why company (with big money) still "waste" their time with placebo. Placebo are effective, sometime even more then the real pill. Here we are not arguing that sugar pills doesn't heal people, we simply say that there is no basis for a cable to make a difference in the sound. That's why there is a double blind test (double is actually that the person listening to it doesn't know which cable is plugged AND (that's where the double come from) the person who ask you doesn't know as well.
  
 Try it for fun, buy a cable even more expensive (who care about the quality) just get the most expensive you can find, you will see that it sound better. That's how human we are made. That's why there is the homeopathie, placebo, etc. There was even an article I saw that was talking about the placebo effect of the fake surgery. Some people get cured without receiving the actual surgery, they basically open them up and close them without doing anything. Result are very impressive (and ethically challenging as well) and we still don't understand how it's even possible. Ha that little thing that nobody fully understand yet, called the brain. Now do you hear a difference, ho yeah! Now do there is a difference, that's an other topic... Are you crazy? No, just human.
  
 Now do I have listen to those expensive usb cable? No, as I'm not inclined to take a sugar pill or homeopathy as well. The audiophile cable there is no logic what so ever being this. Hey, read this: http://gizmodo.com/363154/audiophile-deathmatch-monster-cables-vs-a-coat-hanger
  
 Maybe I should start selling coat hanger as audiophile cable, since they sound as good as monster cable. Now here the real reason why people sell homeopathie or "audiophile" usb cable: http://consumerist.com/2008/02/08/monster-cables-monster-ripoff-80-markups/
  
 Ho yes, what a surprise, money!
  
 I recently looked at those audiophile cable, well a friend was over and he did not believe that people were paying up to $1000 for a cable. I explained him that yeah, people beleive that last 6 inch (for a power cable) will actually made a difference big enough even if that 6 last inch is meaning less if you take into the account all the cable you have inside the wall of your house, or other appliance that do a lot of interference and inject those directly into your electrical system, the shield of the last 6 inch when you look at it in that perspective, is well, meaning less. But still people beleive, that's good. Anyway, I was looking closer, and yes, they put carbon fiber on those connector.Yes it's expensive, and it's light, super cool on a car or on bike, well for something that move, but do you really NOT think that it's a big waste on a connector? Ho well. There is no point of using precious material like gold or silver in a cable as well, but still, so much nicer sounding. 
  
 You may like the look of your cable, but the sound change, seriously, if you want a new sound, change your headphone, amp or even you dac. 
  
 Here a picture of my 5$ usb cable, it's going into what I would call of mess of electric cable before going into my computer (full of noise a computer by the way, but who cares when you shield the last 6 feet). And even if I put my auditor to the max I don't hear any noise. If my usb were adding anything I would logically ear it, if you do, you have a bad dac, get a new one. 
  

 You can see all my non-audiophile cable. Does my setup sound nice? Hell yes, it's simply amazing. 
  
 That was my last post on cable, not that I don't want you to reply, I think everybody is free to argue that my setup is **** and that I'm missing so much, but in fact we never miss what we don't know we could actually be missing.
  
 Have a nice one


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## Lorspeaker

ya, that last inch of brakepads dont matter...same with the tyres. 
 u are not gonna hit on the brakes, u wont feel the lost. 
 good for u. enjoy your ride


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## sANDEKERU

I'm sure audiophile usb cables adds to the wow factor of your setup, but the difference is only cosmetic.
Any USB cable built within the USB standard for quality (copper thickness, twisted pairs etc) and length will do the job just the same (for data transfer) provided there are no defects in the cable.
  
 Audiophile USB cables is pretty much redefining snake oil.


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## Lorspeaker

nah...


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## BirdManOfCT

lorspeaker said:


> nah...


 

 +1.


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## hmorneau

lorspeaker said:


> ya, that last inch of brakepads dont matter...same with the tyres.
> u are not gonna hit on the brakes, u wont feel the lost.
> good for u. enjoy your ride


 
 I will reply even if I said that I won't because it's simply stupid.
  
 Brake pad thickness when new: 12mm
 When pad need to be replaced: 3mm
  
 Same for the tire:
 New tire: 9/32 (for a typical car)
 Replacement at 2/32 (better to do earlier).
  
 So we are talking about of a 9mm of margin for brake pad, and 7/32 of a inch for tire. 
  
 Now your "audiophile cable": 6 feet
 Electrical distribution, at least here in Québec where we get our electricity from: ~1330km 
 Electrical lenght in your wall, around 50 feet, maybe more or less.
  
 If we put those number in perspective, 6 fts vs 50 fts, it would be like your brake pad have a thickness of 14020mm when new and would still be good until they are down to 3mm... So yes, I would not mind of that last 12mm if I had 14008mm still left on my brake pad. 
  
 Not only that, but it doesn't make any sense what so ever, because brake pad are doing the actual braking and it's not sharing it's work with anything else. Your cable doesn't do all the electric distribution, but just the last 6 inch, it would be like arguing that the cable is more important on the sound quality then to actually have an amplifier to connect to it. 
  
 How can people even make an argument like that is over me.
  
 Here some instructive stuff to put a bit of balance in this world: http://xiph.org/video/vid2.shtml


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## Lorspeaker

just bot an audioquest micro-usb cable for my portable ext harddisk... lets see how this 0.75m cable affect my library


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## sANDEKERU

lorspeaker said:


> just bot an audioquest micro-usb cable for my portable ext harddisk... lets see how this 0.75m cable affect my library


 
 It won't affect anything except your wallet. Buying a "audiophile" 0.75m USB cable is like buying sand in sahara (I'm trying to make a terrible comparison) as the main issues with USB arise once you go outside the specs of max USB cable length and there's too much delay.
  
 Edit: the limitation in cable length is actually caused by the speed of the electric signal regardless of how much you pay for the cable or if it's made of silver or copper.


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## Lorspeaker

nah...
  
 tried it b4 with a furutech, i gotten a cleaner, more bodacious sound...v easy to hear.. like a defoamed580
  
 i leave the 010101 science/logic to u scientists


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## Chris J

hmorneau said:


> I will reply even if I said that I won't because it's simply stupid.
> 
> Brake pad thickness when new: 12mm
> When pad need to be replaced: 3mm
> ...




Ummm.....a lot of that harmful electrical noise is generated in your own house by your own equipment?


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## hmorneau

chris j said:


> Ummm.....a lot of that harmful electrical noise is generated in your own house by your own equipment?


 
 Ho yes, it's such an important issue that there is regulation around this to limit the source of Electromagnetic Interference (EMI):
  
 From Wikipedia:
  
 "In the United States, the 1982 Public Law 97-259 allowed the Federal Communications Commission (FCC) to regulate the susceptibility of consumer electronic equipment.[6]
Potential sources of RFI and EMI include:[7] various types of transmitters, doorbell transformers, toaster ovens, electric blankets, ultrasonic pest control devices, electric bug zappers, heating pads, and touch controlled lamps. Multiple CRT computer monitors or televisions sitting too close to one another can sometimes cause a "shimmy" effect in each other, due to the electromagnetic nature of their picture tubes, especially when one of their de-gaussing coils is activated.

Switching loads (inductive, capacitive, and resistive), such as electric motors, transformers, heaters, lamps, ballast, power supplies, etc., all cause electromagnetic interference especially at currents above 2 amps. The usual method used for suppressing EMI is by connecting a snubber network, a resistor in series with a capacitor, across a pair of contacts. While this may offer modest EMI reduction at very low currents, snubbers do not work at currents over 2 A with electromechanical contacts.[8][9]"

 

While a cable with a good shield will prevent radiative noise from those appliance, it won't shield against what is already in your electrical network. EMI transfer as well on conductive (so if it's connected on the same electrical network (which by the way it is, that's why we call it an electric grid), it can get by the cable). 

 

That's why you sometime see cable that look like this:

 



It's a ferrite bead, it can be used to cut interference before it get into an appliance (one of the most effective and least expensive way). It can also cut interference going out of an appliance to meet government regulation. Now why the gov did regulate on this? Because it was cause issue. Electric network have to filter interference as well so they don't transfer between house, and to do that successfully, the best way is to limit them directly at the source. So yes your electrical network is clean enough, but there is already noise in it, but not enough to cause issue with your sound and nothing that your expensive cable will filter out since the shield only block what could radiate into it. And even then a Ferrite bead would be actually better, it will not only filter out the EMI from that got in on that 6 feet cable just before getting into your amp, but it will filter what was actually already on your electrical network. Personally I have already try a cable with one, and I did not notice any difference, probably because the equipment I use already have all the filter embedded in them or they are simply not sensible to them by the way they are designed. 

  
 I know it won't convince anyone, and since a cable with a ferrite bead is so less expensive then your $1000 cable, the placebo won't work as well. So you will actually notice a degradation in sound quality.


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## hmorneau

lorspeaker said:


> ya, that last inch of brakepads dont matter...same with the tyres.
> u are not gonna hit on the brakes, u wont feel the lost.
> good for u. enjoy your ride


 
 Ok, I find an other way to counter that logic.
  
 If you are ready to pay 1000$ for a cable to get the most out of an amp, why would they settle to pay way less for critical equipment in hospital that maintain human alive? Hospital Grade cable are made from copper, no shielding, nothing magic. If one of the people you love was connected to one of those machine, do you really wanted that any radiate nasty stuff could have any effect on the machine performance? Not, but still, that's what they use. And if you believe that your amp is way more sensitive, you are wrong, those equipment are made with tons of very precise electronic. Even for just a risk factor, if some piece cost few thousand not to say few hundred thousand, why would they take any risk by being cheap on that "last 6 feet"... But instead here a case with very critical equipment that "that last inch dont matter..." They just need something that is proven (grade hospital) to be good enough (and that doesn't include magical specification).
  
 Now if you counter argue by saying they must be build to deal with EMI or RFI, then why your soo expensive amp is not build that way as well? (which I assume is probably designed that way). Which prove again that an electric cable should not change the sound. 
  
 Read more here: http://www.head-fi.org/t/171172/the-truth-about-hospital-grade-power-cords


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## Lorspeaker

the heart of the matter is....... 
  
  
  
 in the hearing.


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## Chris J

hmorneau said:


> Ho yes, it's such an important issue that there is regulation around this to limit the source of Electromagnetic Interference (EMI):
> 
> From Wikipedia:
> 
> ...




You're talking to the wrong guy.
I've performed EMC testing.


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## Aradea

Guys, just wanna share my experience
  
 I just tested three different $5  (A to B) USB cables (one with a ferrite bead, other two without) to connect my laptop to my ADL GT40 amp-DAC.
 All three sounded differently: one sounded muffled but with sufficient definition of vocals and instruments , the next one sounded open but lean (a bit harsh in some songs), and the last one just sounded between the two. This last one was the one I use at the end, the one with the ferrite bead.
  
 My silly conclusion is: if you really have to use cheap USB cables, find the one which looked solid and has a ferrite bead hahaha! 
	

	
	
		
		

		
			




  
 Just for laughs guys.. honestly, using a high quality USB cable is not my priority right now but I may get one someday.
  
 Cheers


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## Lorspeaker

lorspeaker said:


> just bot an audioquest micro-usb cable for my portable ext harddisk... lets see how this 0.75m cable affect my library


 
  
 been listening for 3 hours to my setup with the audioguest cable attached to the harddisk...
 my dt150 has never sounded clearer, v happy with this small investment.
  
 http://www.custom-cable.co.uk/audioquest-forest-usb-micro-digital-audio-cable.html


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## ampair

oh, those facepalm moments...
  
@Lorspeaker: i truly hope you set this as a sarcasm trap, if so then shame on me. otherwise i have bad news for you.
 the only way that a "better" usb cable for the ext-hdd may have an influence (if any) on the sound, is when (a) the ground rails of your computer are noisy as hell AND (b) the usb-input of your dac is crappy enough to not isolate the usb ground connectors from the rest of the device. so, either you're a victim to autosuggestion, or your audio-gd generally sucks with usb. your choice 
  
 (if you like, i can elaborate further on the matter. in that case, beware of a veeeery lengthy post.)


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## Tablix

ampair said:


> oh, those facepalm moments...
> 
> @Lorspeaker: i truly hope you set this as a sarcasm trap, if so then shame on me. otherwise i have bad news for you.
> the only way that a "better" usb cable for the ext-hdd may have an influence (if any) on the sound, is when (a) the ground rails of your computer are noisy as hell AND (b) the usb-input of your dac is crappy enough to not isolate the usb ground connectors from the rest of the device. so, either you're a victim to autosuggestion, or your audio-gd generally sucks with usb. your choice
> ...


 
 You bought the can of worms AND opened it   But I cant argue with your post


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## ampair

tablix said:


> You bought the can of worms AND opened it   But I cant argue with your post


 
  
 oh yes, i do like worms. big and juicy ones. perfectly suited for throwing them in the face of whoever sold you the can


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## Chris J

ampair said:


> oh, those facepalm moments...
> 
> @Lorspeaker
> : i truly hope you set this as a sarcasm trap, if so then shame on me. otherwise i have bad news for you.
> ...




I think Lorspeaker is sincere.
Lorspeaker is also entitled to his opinions.


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## Lorspeaker

Just a user, I replaced that stock USB cable betw the laptop n the external portable hard disk...
With an Audioquest with a micro USB cable.

been sleeping with this dt150 for months now, it is like a hd650 kind of sound in a closed can form..
The improved clarity is significantly to my ears...
And pushing the mt220 towards being a tat too bright.

Seems to runs against known digital knowledge which I hv v v little...
Always tot USB cable is just another wire in my setup...
So I tried them out with no mental resistance.
 gone thru Furutech,,wireworld., LAT, cabledyne, Audioquest....
Some are bright, one bodacious, one is holographic. 

Gonna plug it into the fiio e18 next session n give the fx850 a listen...can't wait.


U can start boiling the can of worms..I go enjoy my music..chow!


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## x838nwy

ampair said:


> oh, those facepalm moments...
> 
> @Lorspeaker
> : i truly hope you set this as a sarcasm trap, if so then shame on me. otherwise i have bad news for you.
> ...




If the usb ground is crappy, how can the cable help? The AQ, afaik has no isolating properties. Please elaborate.

Edit: spl


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## x838nwy

Oh, and Lorspeaker was talking about the cable between his hdd and his pc. How does his dac's usb input have anything to do with the hdd->computer connection?


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## Boris Bollokov

There is no difference between £1 cable and £500 if it is built in line with the original specs. But I hear SQ improvement... no you don't, it is placebo. But I ..... no god dammit! 
  
 I am an Audiophile I use my ears, the real deal, not science.... Yeah cool story bro.
  
 Quote:


chris j said:


> I agree.
> Looks crazy.
> 
> 
> ...


 
  
 When i read Jimmer's original post with that quote I LAWLED very hard. But then again not everyone knows the fundamentals of digital signals and technology standards, USB in this case.
  
 Back at Uni I used Data Communications Networking 4th edition by Behrouz A Forouzan. I consider this guy to be the Boss. I wonder how he would have reacted to £500 USB cables 
  
 USB uses digital baseband transmission. The encoding scheme is NRZI. The USB interface never actual sends 1/0s that your PC audio driver generates. The data signal is first NZRI encoded. 
  
 This NZRI encoded digital signal (square wave) is in fact a composite aperiodic analogue signal, not that it matters, just saying. If the USB cable had the bandwidth from 0Hz to Infinity the square wave would always be perfect at the receiving end. In USB binary state 1 is represented by no transition, and binary state zero by a transition.
  
 Below is an example of data signal encoded via NRZI:
  

  
 You can see from the above image that there simply is NO concept of narrow and wide bits. It is just transition states, in case of NRZI transition happens for binary state 1. Each USB packet starts with synchronization (SYNC) field, which is a coded sequence that generates a maximum edge transition density. 
  
I have oppo-ha 1 that uses isochronous transfer mode. The main purpose of isochronous transfer is for applications such as audio data transfer, where it is important to maintain the data flow, but not so important if some data gets missed or corrupted.  If a USB cable is made according to USB 2.0 specs, the PC and the DAC both use USB 2.0 interfaces, then the will be no corruption to the transmitted square wave, no data loss, it will be bit perfect, it will be recovered correctly by the receiver. 
  
 Of course if you have a source of serious EMI next to the cable, then it can corrupt the square wave, and the receiver might not be able to distinguish. 
  
 Some further reading o USB clock recovery:
  
 http://www.cypress.com/?docID=25374


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## Boris Bollokov

x838nwy said:


> If the usb ground is crappy, how can the cable help? The AQ, afaik has no isolating properties. Please elaborate.
> 
> Edit: spl


 
  
 So true, how buying a different cable going to help?
  
 Within the PC chassis it is a very noisy environment. If ground noise is picked up and carried over USB pin 4 (GND), then regardless of what cable you use the noise WILL be carried.
  
 Decent motherboards are likely to be engineered with USB Host EMI Layout Considerations to ensure minimal noise is picked up buy USB circuitry. Also, I would have though a decent DAC will filter pin 4.
  
 http://www.ti.com/sc/docs/apps/msp/intrface/usb/emitest.pdf - Page 5


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## Chris J

boris bollokov said:


> When i read Jimmer's original post with that quote I LAWLED very hard. But then again not everyone knows the fundamentals of digital signals and technology standards, USB in this case.
> 
> Back at Uni I used Data Communications Networking 4th edition by Behrouz A Forouzan. I consider this guy to be the Boss. I wonder how he would have reacted to £500 USB cables
> 
> ...




Wow!
I posted that way back in February 2014!

Interesting explanation, BTW.


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## Boris Bollokov

I was reading this thread from the start only today  and that part about bits made me laugh


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## Chris J

boris bollokov said:


> I was reading this thread from the start only today  and that part about bits made me laugh




Right, now I remember, Jimmers supplied us with a very funny quote from a Hi Fi magazine about "the little bits being high frequency content".
Ummm, OK.:rolleyes:


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## nicholars

I am cynical with things like this and try to be "objective" about it.... but I had my D1050 connected to my PC with a cheap 3m printer cable I found lying around, I wanted to use USB async on my DAC but was a bit disappointed that the USB connection sounded worse than the SPDIF coaxial from my Xonar STX.... I bought a £20 QED graphite 2m audio USB cable and plugged it in expecting probably nothing.... Surprisingly no grain in the sound and the USB async connection sounds the same or better than the SPDIF connection. I am not imagining it either there is definitely harshness / grain / sibilance on the cheapo 3m cable whereas the QED 2m audio cable sounds clean and a lot better (like the coaxial SPDIF from Xonar STX does). I wouldn't expect a USB cable to change the frequency response or anything like that, but it seems a decent cable vs a crap one can clean up the sound, I have no desire to spend any more than £20 or try any other cables as I think a decent, short as possible, audio USB cable is all you need compared to a £1 3m printer cable.


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## Kane Williams

What about Y cables that split the data and 5V power, so one can disconnect the power going to the DAC altogether (after handshake) if the DAC runs on battery or another PSU? Is there any scientific proof that USB Bus power can degrade the audio?
  
So why does everyone rave on about asynchronous USB for audio if isochronous transfer was designed for audio etc?


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## nicholars

kane williams said:


> What about Y cables that split the data and 5V power, so one can disconnect the power going to the DAC altogether (after handshake) if the DAC runs on battery or another PSU? Is there any scientific proof that USB Bus power can degrade the audio?
> 
> So why does everyone rave on about asynchronous USB for audio if isochronous transfer was designed for audio etc?


 
  
 Basically because async is controlled by the DAC and then a very short distance from USB chip > DAC chip so it will have less jitter whereas isochronous is controlled by the clock in the PC which is obviously not going to be as good as the DAC.


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## Kane Williams

I knew that Asynchronous was to do with the DAC doing the clocking but having read this following statement, it sounds like isochronous, was designed with audio in mind too?

"I have oppo-ha 1 that uses isochronous transfer mode. The main purpose of isochronous transfer is for applications such as audio data transfer, where it is important to maintain the data flow, but not so important if some data gets missed or corrupted. If a USB cable is made according to USB 2.0 specs, the PC and the DAC both use USB 2.0 interfaces, then the will be no corruption to the transmitted square wave, no data loss, it will be bit perfect, it will be recovered correctly by the receiver".


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## nicholars

kane williams said:


> I knew that Asynchronous was to do with the DAC doing the clocking but having read this following statement, it sounds like isochronous, was designed with audio in mind too?
> 
> "I have oppo-ha 1 that uses isochronous transfer mode. The main purpose of isochronous transfer is for applications such as audio data transfer, where it is important to maintain the data flow, but not so important if some data gets missed or corrupted. If a USB cable is made according to USB 2.0 specs, the PC and the DAC both use USB 2.0 interfaces, then the will be no corruption to the transmitted square wave, no data loss, it will be bit perfect, it will be recovered correctly by the receiver".


 
  
 Everything I have read says that well implemented async USB is the best out of all digital connections to DAC.
  
 I think that is a typo.... On the oppo website it says "Asynchronous USB DAC"


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## x838nwy

Isn't a step change a bunch of sines? So if we're talking a very abrupt step, then it can be approximated into a number of high freq. sines. So "the bits are high freq." or whstever is not entirely incorrect.


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## Chris J

x838nwy said:


> Isn't a step change a bunch of sines? So if we're talking a very abrupt step, then it can be approximated into a number of high freq. sines. So "the bits are high freq." or whstever is not entirely incorrect.




Well you are correct, the step waves are really just a bunch of sine waves.

But the original statement which was quoted way back when made it sound like the small bits are high frequencies, the wide bits are low frequncies. That part is not true.


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## Kane Williams

So anyone tried the Audiocadabra Optimus USB cable? I like the idea of a split power/data cable like the ifi one but would cheaper.


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## Kane Williams

I ended up buying a Y style (split power/data)  USB cable from Achtung Audio on Ebay. I was hoping that I would be able to disconnect the power leg of the Y cable altogether once the initial handshake between my MBP and Ifi Nano had been made, but unfortunately, this just results in the laptop disconnecting from the DAC. Bummer!


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## cablepro98

I'd say that the difference in usb is not really about pcocc silver and all that "voodoo" but rather what makes the biggest difference is capacitance low for data to reduce jitter but high on power side for usb powered dacs because high frequency roll off would be good considering how noisy the power most computer usb ports have.


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## dmbr

I got good results from the iFi Gemini cable.

Anyone compared it to alternatives?


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