# USB cable and Sound Quality



## RudyBagel

Dare I put my toes into the water? I'm a physicist and audiophile (establish credibility!). I've been into living room system audiophilia for 20 years. This pc-audio is new to me and I'm just starting up. Now, about USB cables: I can hear a small difference between cables. If we assume the bits are transferred properly (and there is some debate  about that in USB-audio vs. USB-data), I think the issue is electromagnetic nosie getting through the circuits and into, in my case, the headphone amplier. All EM noise is immediately spread through an entire system, end-to end. Since at the end of the day, something is converted to analog to hear it, the cleaner the power and the better the shielding, the cleaner the final D/A will be. This will not be anything that affects data transfer, per se. All billion TB of information can be transferred with perfect fidelity; when you open your word document, all the correct words are there. But we don't listen to data files. There has to be analog conversion somewhere. In my living room system, it was always well worth the effort to clean up the power and have well shielded cables. Do any of the audiophile USB cables actually provide effective power filtering and shielding, such that the headphone amp is cleaner even though connected to the PC? I don't know. This can be properly done in a living room system. But there are snake-oil produccts there too, of course.


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## proton007

A similar thread got locked just yesterday. Whats the point of this one?


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## liamstrain

Line noise in a USB cable would be irrelevant at the D/A conversion point unless it was so problematic as to actually affect the voltage swing enough to switch bits (extremely unlikely). 
   
  Any noise you hear after the D/A conversion would more likely be coming from somewhere else in the chain and should be unaffected by the USB cable. I could see maybe some case if the amplification circuit is powered via the USB... a ferrite choke cost about $2, and would be any easy thing to add to any USB cable to test if you continue to think that the culprit lies there.
   
  You state you heard differences between them. Did you do any sort of controlled/blind testing or ABX to determine this, or is this based on your own cable switching and general impressions.


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## Griploc

I emailed a lady at mapleshade audio about isb quality and here is wht she had to say:

The USB cable that we offer, the Clearlink USB, provides two main benefits which will enhance both audio conversion and sonics:
Our signal wires are not bundled together with the USB power wires, which allows the signal wires to perform with less interference. If the conductor that is transmitting the signal is not fighting with interference, the end result is a more efficient signal which provides clearer sound. This is important because digital audio signals are prone to problems that analog is not, and if you can address those problems it will sound noticeably better. The other main benefit has to do with the materials used, which also allow the signal to travel more efficiently and with less interference. We use a very thin copper conductor and good-sounding dielectric. Both the design and materials have benefits for sonics and audio conversion. If you would like more detailed technical information, please feel free to contact our tech advice support at tweaks@mapleshaderecords.com. Thanks.


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## Griploc

USB"


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## BlackbeardBen

How about mailing someone at the USB foundation instead?
   
  That would be infinitely more useful than the marketing spiel from a cable company.


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## billybob_jcv

With digital, how does "a more efficient signal" translate into "clearer sound"???  Is she suggesting that line interference would be causing transmit/receive errors?  If that were the case, I don't think it would be subtle at all - you would have signal dropouts and possibly stuttering - just like you do with any digital sound transmission (VoIP phones, cell phones, etc).  A dirty CD isn't subtle...


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## LFF

Quote: 





billybob_jcv said:


> With digital, how does "a more efficient signal" translate into "clearer sound"???  Is she suggesting that line interference would be causing transmit/receive errors?  If that were the case, I don't think it would be subtle at all - you would have signal dropouts and possibly stuttering - just like you do with any digital sound transmission (VoIP phones, cell phones, etc).  A dirty CD isn't subtle...


 

 Line interference inject noise into the signal. That's why I have purchased a Uber Sonic Bandwidth Cord from an engineering friend. It's a custom designed cable that rejects noise and custom made to reproduce those 1's and 0's in the most straight (for 1's) and curvy ( for 0's) way possible.
   
  With this cable, I get no signal dropouts and no stuttering. It's simply amazing. I was told that each cable gets blessed by a JEDI and that the designer crys every single time he sells one because they are so dear to his heart and mind.


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## ultrabike

Quote: 





rudybagel said:


> There has to be analog conversion somewhere


 
   
  Correct, but the analog conversion does not happen at the USB interfaces.
   
  USB 3.0 expects a bit error rate of less than 10^-12 according to the spec: http://www.usb.org/developers/docs/ (USB3_r1.0_06_06_2011.pdf section 3.2.4.1 and 4.4.10.1) Furthermore, the cable description to fulfill the requirements is specified clearly in section 11.4.7 (28 AWG for 0.8m all the way to 20 for 5.3m.) These requirements don't seem too unreasonable in terms of $.


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## Griploc

The usb cable mapleshade audio sells are built from the ground up and custom ordered so i think she may have an idea what she is saying


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## rhythmdevils

Wow I would love to come over and feel your 1's and 0's some time LFF too bad we dont' live closer.  USB cables are so important, I don't get why all those crazies say they don't matter.  The thicker, harder, longer, and stiffer the better.  Mine is so girthy and stiff that I have to keep the back of my dac facing the back of my puter.  But man those 1's and 0's come through in such glory.  It could also be the virgin goat entrails I had custom lined on the inside of mine too.  It adds an organic richness plus it lactose free.  Win win win.


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## ultrabike

Quote: 





griploc said:


> The usb cable mapleshade audio sells are built from the ground up and custom ordered so i think she may have an idea what she is saying


 
   
  I'm not sure how building something "from the ground up" and "custom" ordering means she knows what she is saying.
    
  Quote:


griploc said:


> This is important because digital audio signals are prone to problems that analog is not


 
   
  She should elaborate on this.
   
  Quote: 





griploc said:


> The other main benefit has to do with the materials used, which also allow the signal to travel more efficiently and with less interference. We use a *very thin copper conductor* and *good-sounding dielectric*. Both the design and materials have benefits for sonics and audio conversion. If you would like more detailed technical information, please feel free to contact our tech advice support at tweaks@mapleshaderecords.com. Thanks.


 
   
  The thinner the conductor, the worse it performs. AFAIK there is no such thing as good-sounding dielectric.


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## Griploc

Could you support data regarding good dielectric not sounding good


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## purrin

Because any dielectric will polarize the electrons. Essentially the cable becomes a capacitor.
   
  The EMI theory however is more sound. I actually got a subtle, but notable improvement by wrapping my USB cable with aluminum foil.


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## Griploc

Interesting. I emailed the company's tech support to elaborate with supporting data and graphs to berify their claims. I will post the answer back as soon as i recieve it


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## Griploc

Verify'


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## LFF

Quote: 





purrin said:


> Because any dielectric will polarize the electrons. Essentially the cable becomes a capacitor.
> 
> The EMI theory however is more sound. I actually got a subtle, but notable improvement by wrapping my USB cable with aluminum foil.


 

 That's awesome. Mine has aluminum wrapped in copper wrapped in a condom. They are all supposed to suppress things from penetrating into the signal.
   
  Mine is a bit thicker than yours though. It should be....cost me nearly $6,900.00!


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## rhythmdevils

Are you going to release an aluminum foil wrapped paradox to keep aliens from degrading the audio signals?


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## LFF

Quote: 





rhythmdevils said:


> Are you going to release an aluminum foil wrapped paradox to keep aliens from degrading the audio signals?


 

 No.
   
  I'm importing unobtanium from Pandora. Should be getting vetted by the JEDI council in short time.


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## Draygonn

I want a JEDI Cable too!


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## rhythmdevils

Quote: 





lff said:


> I'm importing unobtanium from Pandora. Should be getting vetted by the JEDI council in short time.


 
   
  That sounds stupendous.  I'm hoping to get my aluminum T50rp mods RexAeterna Certified ® sometime in the next couple weeks.


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## billybob_jcv

Quote: 





griploc said:


> Interesting. I emailed the company's tech support to elaborate with supporting data and graphs to berify their claims. I will post the answer back as soon as i recieve it


 
   
  Right, get more pseudoscience from the company selling the product.  I hope the graphs are in color, that makes them more impressive and will help convince everyone...


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## liamstrain

Quote: 





griploc said:


> The other main benefit has to do with the materials used, which also allow the signal to travel more efficiently and with less interference.


 
   
  It's still ones and zeros. As I stated above, you have REALLY screw up the signal to make it not read as ones and zeros. Interference up until that point, is irrelevant since it does not change the data the D/A conversion uses. The only other factor that *might* come into play is jitter. Which: 1) has not been demonstrated to be audible. 2) USB standards already have a certain amount of compensation for. 3) Is dealt with by many (if not most) D/A systems - especially async and anything that reclocks. and 4) you have to work really hard to generate an appreciable amount of in a short cable. 
   
   
   
  Quote: 





> We use a very thin copper conductor and good-sounding dielectric. Both the design and materials have benefits for sonics and audio conversion.


 
   
   
  No. These are not audio cables. There are no sonics. It is data. Ones and zeros. Unless the cable changes the order of the ones and zeros (and does so smartly - which ones and zeros are better bass? which ones are clearer treble?) then there is no way for the cable to affect the sound except to degrade it so far as to make it unreadable. 
   
  There *might* be an argument to be made if your device is powered off the USB bus, for the power component to affect the amplifier circuit. But not the D/A - and one would still need to provide actual evidence that this is the case.


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## ultrabike

Quote: 





griploc said:


> Could you support data regarding good dielectric not sounding good


 
   
  Read this article: http://www.audioholics.com/education/cables/dielectric-absorption-in-cables-debunked
   
  Furthermore, like so many have said in so many different ways, USB does not pass analog audio signal, it passes binary packets of data. Also, consider that USB 3.0 max nominal speed is 5 Gbps. Audio packets should be effortless and with negligible bit error rates if using standard recommended stock cable.


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## Griploc

Here is the reply back fro pierre, the founder of mapleshade audio:

Using current methods of measuring cables--that is, methods that are entirely limited to  how well they pass sine wave based test signals--assuming you had measuring instruments of cutting edge resolution, you would certainly be able to show measurable differences between cables of varying geometries and materials. And those differences would be guaranteed to be completely unrelated to which cables sounded better and which ones sounded worse. 

Why? Very simply because 1) no combination of sine waves (which are extremely simple, smooth and repetitive in shape) can begin to approximate the extraordinarily complex, sharp edged and non-repetitive waveform patterns of real musical instruments; and b) because of their inherently non-linear response, how wires/speakers/amplifiers/CD players/etc. respond to repetitive sine wave patterns is entirely different than how they respond to non-repetitive music waveforms. 

In fact, it is possible to demonstrate that the more you tailor the design of wires or electronics to pass sine waves accurately, the worse the wires or electronics sound with real music. Classic current examples of this are the MIT speaker cables, which are, of all cables on the market, the ones that are the most slavishly tailored to yield the best possible sine wave accuracy. The result of MIT's meticulous sine wave optimization is that our $120 Golden Helix speaker cable consistently beats their $10,000 Oracle cables in head-to-head listening tests.

Until audio engineering develops measurement techniques based on a library of real music waveforms (a very difficult task indeed), disciplined listening panel tests conducted by people who hear live, unamplified music at least once a week will remain a vastly more  accurate and scientifically reliable measurement tool than any currently known electronic instruments. And wires or speakers or electronics developed by meticulous experimentation using such listening tests will continue to sound strikingly and obviously better than those developed only according to sine wave theory and measurements.

Where does this leave you with respect to evaluating the Clearlink USB cable? Very simple: you can purchase it, borrow a much more expensive USB cable from a dealer or friend and listen to both, using identical one minute passages from well-recorded test files that you are really familiar with. Your ears will tell you whether there's a difference. And our money back guarantee means this experiment will cost you nothing but postage. Speaking of the importance of empirical evidence from listening tests: to date, we have sold multiple hundreds of our Clearlinks with that same money back guarantee; not one has been returned because it sounded inferior or only equal to the expensive wire our audiophile customers were already using.

If you're interested in more detailed information on any aspect of the above, please feel free to call me at our tech advice line, 410 867-7543.


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## Griploc

I am well aware the digital data is transferred in packets. I took a course in audio engineering and music production which explained this thouroghly a few years back. I only wish to recreate analogue information in the digital realm to a very close emulation. I have to admit though his pitch to sell his product is smeared and stepped away from the graphs and charts info which had me doubting his info.

Vibration control is something i am a firm believer about which is his area of expertise(pierre) and have heard it for myself which is a night and day transformation. 

I will listen to another highly respectble companys usb cable within the next few weeks and honestly give my feedback on the basis of true and false


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## billybob_jcv

Let me summarize his message:  "There are mysteries in audio that can't be measured.  Trust me, our cables are better."
   
  Where in his information did he make the distinction between analog and digital information?  No where.  His discussion of complex music waveforms is complete bunk.  Combining sinewaves of different amplitudes and frequencies does not present a problem for a cable, and it has ZERO to do with a digital signal.
   
  Unless your listening is done as part of a double-blind test, it means nothing - except that you will feel better about your desire to spend this money.   
   
  It is the same old subjective vs objective argument:  Golden ears claim to hear things that can't be measured.  Either you believe that or you don't.


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## liamstrain

Quote: 





griploc said:


> I will listen to another highly respectble companys usb cable within the next few weeks and honestly give my feedback on the basis of true and false


 
   
  Be sure to have them blindly switched out by someone other than you periodically. That will help remove some bias in your listening (usually unconscious). 
   
  Better if you can do a true abx or dbt, but that can be hard to manage on your own. 
   
  As for Pierre's comments - he managed to avoid providing evidence, neglected that this was digital vs. audio (and his audio information was poor anyway), or even solid electrical theory in his response. There are some things in audio cables that can affect the sound (RLC), and his lacking even the mention of those elements convinces me that it is safe to say that he has no idea what he's talking about.


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## nick_charles

Quote: 





griploc said:


> Why? Very simply because 1) no combination of sine waves (which are extremely simple, smooth and repetitive in shape) can begin to approximate the extraordinarily complex, sharp edged and non-repetitive waveform patterns of real musical instruments;


 
   
  Just plain nonsense and clearly written by someone who does not understand even the basics of Digital Audio re how sampling and reconstruction happens, this pervasive "sine waves are easier than music" is just out and out wrong and yet keeps getting trotted out again and again and again !
   
  Quote: 





> Originally Posted by *Griploc*
> 
> In fact, it is possible to demonstrate that the more you tailor the design of wires or electronics to pass sine waves accurately, the worse the wires or electronics sound with real music. Classic current examples of this are the MIT speaker cables, which are, of all cables on the market, the ones that are the most slavishly tailored to yield the best possible sine wave accuracy. The result of MIT's meticulous sine wave optimization is that our $120 Golden Helix speaker cable consistently beats their $10,000 Oracle cables in head-to-head listening tests.


 
   
  A comparison with MIT is very telling as they are a company that routinely bungs RC netwoks on their cables and peddles made up and irrelevant parameters (articulation, energy storage)  - not a good point of comparsion if you want to be taken seriously !
   
  Notwithstanding that , how about some blind listenintg tests to back this up ?
   
   
   
  Quote: 





> Originally Posted by *Griploc*
> 
> Until audio engineering develops measurement techniques based on a library of real music waveforms (a very difficult task indeed), .


 
   
  It is utterly trivial to send a real music signal down a cable and measure what comes out of it, I've done this with a $30 sound card !


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## nick_charles

Quote: 





liamstrain said:


> Be sure to have them blindly switched out by someone other than you periodically. That will help remove some bias in your listening (usually unconscious).
> 
> Better if you can do a true abx or dbt, but that can be hard to manage on your own.


 
   
  Or take the analog output and digitally record that for both cables and compare - this will show any differences very easily


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## liamstrain

Quote: 





nick_charles said:


> Or take the analog output and digitally record that for both cables and compare - this will show any differences very easily


 
   
  Good call. I think there is also value in a controlled listening test.


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## billybob_jcv

The problem with recording and comparing the signals is that it doesn't account for the magic that Pierre claims can't be measured.  He would just claim that neither the input nor the output show the signal that he can hear.  I would like to see him claim to hear a difference on a null signal - you could DBT him against a cable that isn't connected...


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## liamstrain

Quote: 





billybob_jcv said:


> I would like to see him claim to hear a difference on a null signal - you could DBT him against a cable that isn't connected...


 
   
  Would be curious to see how he would handle a DBT at all - especially interpretation of results. For kicks, I'd want to have some control duplicates in there.
   
  Of course, he would say that the testing method was invalid for some reason (unrealistic listening conditions, poor room, bad vibration control, etc.) But in the end, I'm not here to bash him. He just didn't answer the questions posed to him in a useful way - which is frustrating, if unsurprising.


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## billybob_jcv

Oh my, "pierre" is Pierre Sprey, a very well known figure in aerospace & defense.  As a fellow aeronautical engineer, I'm appalled that one of our own would go down the subjective path.
http://www.washingtonpost.com/wp-dyn/content/article/2006/05/15/AR2006051501518.html


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## nanaholic

Quote: 





griploc said:


> Why? Very simply because 1) no combination of sine waves (which are extremely simple, smooth and repetitive in shape) can begin to approximate the extraordinarily complex, sharp edged and non-repetitive waveform patterns of real musical instruments


 
   
  This is pure BS.  We have a whole mathematical field dedicated to representing non-periodic waveforms as a combination of sine waves (refer to Fourier series Fourier transform and Fourier integrals etc) of which we build our entire digital communications world upon this very field.  If we can't represent complex waveforms with the Fourier theories this very digital computer world you live in now simply doesn't exists.


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## nick_charles

Quote: 





nanaholic said:


> This is pure BS.  We have a whole mathematical field dedicated to representing non-periodic waveforms as a combination of sine waves (refer to Fourier series Fourier transform and Fourier integrals etc) of which we build our entire digital communications world upon this very field.  If we can't represent complex waveforms with the Fourier theories this very digital computer world you live in now simply doesn't exists.


 
   
  You are the 3rd person to critique that section, but your explanation is the best


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## nick_charles

Quote: 





billybob_jcv said:


> Oh my, "pierre" is Pierre Sprey, a very well known figure in aerospace & defense.  As a fellow aeronautical engineer, I'm appalled that one of our own would go down the subjective path.
> http://www.washingtonpost.com/wp-dyn/content/article/2006/05/15/AR2006051501518.html


 
   
  You can be subjective without purveying nonsense, it is the promotion of nonsense by someone who should know better that is the real tragedy


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## Griploc

Great info. I will do blind tests and record it via analogue recorder and a digital interface to hear if it is any different


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## Griploc

The two companies i deal with are extremely well respected in their knowledge and products they provide. It is hard to swallow the last message i recieved from a man with a calabur of his experience that wasnt fully explained or accurate in terms of digital cables rather than analogue terminoligy descriptions.


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## billybob_jcv

FYI - here's some light reading for you...
  http://www.usb.org/developers/docs/usb_20_071012.zip


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## Griploc

I will download it after work today. Looking forward to the read


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## LFF

OK...apparently my responses here have triggered some discussions.
   
  I have been contacted by an audiophile cable manufacturer in order to review a prototype cable they are designing. It will retail from $300 to $1,000 depending on length and connectors. They are said to be "revolutionary" in their design and I have been offered a discount to review them. I decided to order their 60 inch cable which runs for $800.00 plus shipping. I was offered an 80% discount as a "reviewer discount". I figured it wasn't much of an investment to try out something "revolutionary" so I have pulled the trigger.
   
  I'll report back on it once I get it in 3 - 4 days.


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## dleblanc343

Quote: 





lff said:


> OK...apparently my responses here have triggered some discussions.
> 
> I have been contacted by an audiophile cable manufacturer in order to review a prototype cable they are designing. It will retail from $300 to $1,000 depending on length and connectors. They are said to be "revolutionary" in their design and I have been offered a discount to review them. I decided to order their 60 inch cable which runs for $800.00 plus shipping. I was offered an 80% discount as a "reviewer discount". I figured it wasn't much of an investment to try out something "revolutionary" so I have pulled the trigger.
> 
> I'll report back on it once I get it in 3 - 4 days.


 

 May I ask what the company is?


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## anetode

I'm guessing Cardas. LFF is a big fan.


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## liamstrain

Quote: 





lff said:


> OK...apparently my responses here have triggered some discussions.
> 
> I have been contacted by an audiophile cable manufacturer in order to review a prototype cable they are designing. It will retail from $300 to $1,000 depending on length and connectors. They are said to be "revolutionary" in their design and I have been offered a discount to review them. I decided to order their 60 inch cable which runs for $800.00 plus shipping. I was offered an 80% discount as a "reviewer discount". I figured it wasn't much of an investment to try out something "revolutionary" so I have pulled the trigger.
> 
> I'll report back on it once I get it in 3 - 4 days.


 
   
  Cool. Be sure to provide your testing methodology and controls so others can duplicate your experiments.


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## billybob_jcv

For $1,000, I would expect the music to fly out of the end of the cable without being connected to the source, amp or speakers...


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## paradoxper

Quote: 





lff said:


> OK...apparently my responses here have triggered some discussions.
> 
> I have been contacted by an audiophile cable manufacturer in order to review a prototype cable they are designing. It will retail from $300 to $1,000 depending on length and connectors. They are said to be "revolutionary" in their design and I have been offered a discount to review them. I decided to order their 60 inch cable which runs for $800.00 plus shipping. I was offered an 80% discount as a "reviewer discount". I figured it wasn't much of an investment to try out something "revolutionary" so I have pulled the trigger.
> 
> I'll report back on it once I get it in 3 - 4 days.


 
  What kind of cable exactly? (connector wise)


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## LFF

Quote: 





paradoxper said:


> What kind of cable exactly? (connector wise)


 

 I asked for [size=11.0pt]a B-Style USB to Standard USB Connector.[/size]


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## LFF

Quote: 





dleblanc343 said:


> May I ask what the company is?


 
   
  I was just contacted by a German company rep. His sig read Blau Anbruch. 
	

	
	
		
		

		
			




   
  They are shipping it directly from their plant in China.
   
  Quote: 





anetode said:


> I'm guessing Cardas. LFF is a big fan.


 
  Nope.
   
  Quote: 





liamstrain said:


> Cool. Be sure to provide your testing methodology and controls so others can duplicate your experiments.


 
  I surely will.


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## LFF

Update...I just got a big refund. Their 60 inch USB cable is $300.00....not $800.00!


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## ultrabike

Going from $800 to $300 you should go from the "72 virgins" experience to the "Oh-Mie-Gwad" experience.


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## LFF

Quote: 





ultrabike said:


> Going from $800 to $300 you should go from the "72 virgins" experience to the "Oh-Mie-Gwad" experience.


 

 LOL!
   
  We shall see....


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## rhythmdevils

I don't know, I think it will probably suck then.  300 isn't nearly enough to develop proper expectations.


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## dleblanc343

I've tried the audioquest diamond usb, and I have to admit it was quite an innovation. Made me believe in digital cable differences; something I was highly skeptical about.


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## liamstrain

Quote: 





dleblanc343 said:


> I've tried the audioquest diamond usb, and I have to admit it was quite an innovation. Made me believe in digital cable differences; something I was highly skeptical about.


 
   
  Did you blind test it against other cables?


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## LFF

Quote: 





rhythmdevils said:


> I don't know, I think it will probably suck then.  300 isn't nearly enough to develop proper expectations.


 

 Certainly enough to provide _some_ expectations.
   
  And cheaper than this or this one.


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## billybob_jcv

So, the $300 USB cable can do magical things, but it can be built in the same Chinese factory that builds the $2 USB cables.  How convenient!


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## Subsequence

So when using an expensive usb cable soldered with the tears of puppies, the hair of unicorns as a conductor and insulated with a super thick coating of fud(air is the best insolator and this one surely has a lot of hot air), connected via extension cable to your dac... Does that mean i just bought a ticket to hell?


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## liamstrain

No. The puppy tears (in the solder) are protection against damnation. 
   
  Seems counter-intuitive, I know... but we have blind testing data to support this.


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## LFF

Quote: 





billybob_jcv said:


> So, the $300 USB cable can do magical things, but it can be built in the same Chinese factory that builds the $2 USB cables.  How convenient!


 

 Seriously.
   
  I haven't seen the cable but if I get a regular ol' USB cable...well...I'll chalk it up to experience.


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## Subsequence

Quote: 





liamstrain said:


> No. The puppy tears (in the solder) are protection against damnation.
> 
> Seems counter-intuitive, I know... but we have blind testing data to support this.


 
  But what if you use your gold plated ears?
  Quote: 





lff said:


> Seriously.
> 
> I haven't seen the cable but if I get a regular ol' USB cable...well...I'll chalk it up to experience.


 
  On the bright side i'm sure it will be thick enough to tow a car!


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## LFF

Quote: 





subsequence said:


> On the bright side i'm sure it will be thick enough to tow a car!


 
   
  I'll let you know. Cable is set to arrive tomorrow!


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## Griploc

I have a stefan audio art endorphin USB cable set to arrive in late august. I ordered it a month ago and it will take 3 weeks to build after his other orders that are in front of mine are done. Mine doesnt cost 800 but it does cost about 350. I will sirely blond test it against a generic and apogee USB cable. I will have one of my students switch the cables.


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## nick_charles

Quote: 





griploc said:


> I have a stefan audio art endorphin USB cable set to arrive in late august. I ordered it a month ago and it will take 3 weeks to build after his other orders that are in front of mine are done. Mine doesnt cost 800 but it does cost about 350. I will sirely blond test it against a generic and apogee USB cable. I will have one of my students switch the cables.


 
   
   
  DBT is better. You will need two students. Both should be unaware of the price or identity of the cables or the purpose of the test - the cables should be merely labelled A and B, if you can sheath them in something like rubber hose that may help.
   
  Get one student to toss a coin 20 times - heads = cable A, tails = cable B and write down the order.
   
  That student swaps cables between trials but does not reveal to anyone during the experiment which cable is in use at any time. Nothing else is changed.
   
  A second student ushers you in and out of the room and makes sure you don't peek. This 2nd student does not know what cable is being tested but records your answer for each trial i.e which cable you say you are listening to. NOT any vague subjective stuff -* just A or B*
   
  Perform *a minimum of 20 trials *- you will need to score at least 15/20 to demonstrate an audible difference


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## billybob_jcv

If I had no scruples and big brass ones, I would buy a container load of cables from Monoprice, sprinkle them with stripper dust (glitter), send a free one to 6moons, Stereophile and the other high priests, and build a web site offering them for $350.  I think Patrick might have the right idea...


----------



## Griploc

I have never hear of dbt. Can u send a link?


----------



## Griploc

I think the abbreviation was for double blind test... If so i am an idiot, i thought you were reffering to a brand of usb cable. I will use two students and follow the procedure you specified. I have proper vibration control system and i will monitoring through my apogee symphony io interface listening through a pair of akg k 702 and a pair of mackie hr 824 mk 2 nearfield monitors for referencing among other headphones in the akg line such as the k 240's and k 271's in protools 9 and logic as well as itunes wav audio files, recordings as well to see if any changes in sonics and data bits are relevant in conversion.


----------



## joeyjojo

The set up you describe nick_charles is hard though as he has no reference for A and B. When I think of double blind I think of the foobar ABX plugin - you get an A, B, X and Y sample and need to match A to X and B to Y or A to Y and B to X correctly. Also the time between trials will be large while he gets ushered in and out of the room, audio "memory" is shorter than that no?
   
  Still, I hope some kind of experiment goes ahead, I'm very interested


----------



## nick_charles

Quote: 





joeyjojo said:


> The set up you describe nick_charles is hard though as he has no reference for A and B. When I think of double blind I think of the foobar ABX plugin - you get an A, B, X and Y sample and need to match A to X and B to Y or A to Y and B to X correctly. Also the time between trials will be large while he gets ushered in and out of the room, audio "memory" is shorter than that no?
> 
> Still, I hope some kind of experiment goes ahead, I'm very interested


 
   
   
  It is less of a problem than you think. The guinea pig subject can listen sighted as long as he/she wishes* before *the test. This allows the subject to be familiar with the _sound_ of the two stimulae. I should have mentioned this but it is common practice in audio tests to allow listeners to have sighted experience first - sorry, my bad. So before the blind tests the listener has a conception of how the two items sound and the blind part is to confirm that their conception is accurate when other clues are removed.
   
  I agree there are issues with delay and audio memory and a random ABX box is a* much better solution in general*.
   
  However, most DACs have only 1 USB input and so even if you have a switching box with 2 USB in and one out you have an extra USB cable so you would need two of the super-duper cables otherwise an intervening bog-standard cable would be deemed to nobble the super cable, then you have the issue of feeding two identical signals into the box so you would need two computers running the same software/music and carefully time-aligned on each trial, even a slight misalignment would easily identify A from B when compared with X.
   
  If you had a DAC with two USB inputs you could switch between them , but then you do not have an X just A and B, you still have the sync problem even if you have one computer running two instances of the same media player through different USB ports (if this is even possible)
   
  You could do rapid cable swaps behind a curtain (Single blind) but then you have the Clever Hans problem where the invigilator can consciously or unconsciously give clues as to the identity of the cable, perhaps one is harder to fit or takes more effort to remove.
   
  One way you might manage it would be to have two identical DACs fed from two identical computers carefully sync'ed, feed the fixed line-level outputs (using identical analog cables) to an ABX box which sends A or B to an amp depending on the switching.
   
  Personally how I would do it would be to digitally record the analog line-level outs from the DAC fed by both cables, run the results through a spectrum analyzer (run the math on them)  or set up Foobar blind tests between two carefully trimmed and aligned samples, but then the objection is that the digitizing process obscures the differences between the cables even if it is accurate to 16 or 20 bits.


----------



## LFF

CABLE IS HERE!!!!


----------



## autumnholy

Quote: 





lff said:


> CABLE IS HERE!!!!


 
   
  Let the fun begins...


----------



## Subsequence

Quote: 





lff said:


> CABLE IS HERE!!!!


 
  I don't think i've ever been this excited over a cable


----------



## Silent One

Quote: 





subsequence said:


> Quote:
> 
> 
> 
> ...


 
   
  (Silent One quietly takes a seat)


----------



## Matt head 777

I heard you can induce a current if the lighter usb cable is vibrated it can alter the signal enough to introduce a posynomial 
  signal.


----------



## Grev

That cable is bollocks.


----------



## LFF

Just a tease....


----------



## zenpunk

Those connectors must be extremely fragile to be so carefully wrapped


----------



## ultrabike

The connector wrapping is not to protect the cable, It's there to protect the owner from being accidentally shot with awesomeness.


----------



## anetode

I resent all this cynicism over what appears to be a perfectly functional USB cable/mooring line/climbing rope.


----------



## Subsequence

Good god man, do you have to feed it a rat every 2 weeks?


----------



## LFF

Quote: 





ultrabike said:


> The connector wrapping is not to protect the cable, It's there to protect the owner from being accidentally shot with awesomeness.


 
  Damn....I knew that's what it was for!!!  
	

	
	
		
		

		
		
	


	



   
  Testing it out as I type....


----------



## DaBomb77766

Quote: 





lff said:


> Just a tease....


 
  That...looks a lot like a garden hose. 

 I find this thread very amusing.


----------



## LFF

Quote: 





dabomb77766 said:


> That...looks a lot like a garden hose.
> 
> I find this thread very amusing.


 
  Nah...it has no metal hose attachment part.

 Also...it's in Cardas blue!!!


----------



## BlackbeardBen

Quote: 





dabomb77766 said:


> That...looks a lot like a garden hose.
> 
> I find this thread very amusing.


 
   
  Suspiciously similar:
  
  http://anythingbutipod.com/2008/04/the-absoute-best-sounding-cables-ever-velumnatics-audiophlow/


----------



## grokit

The AudioPhlow 420


----------



## Subsequence

Quote: 





> The cabling itself is a technology licensed from a German aerospace firm called *Gaurdenhose* Polyimeplastic.


 
  Are you kidding me?


----------



## El_Doug

I guess the fact that it's a joke went right over your head? 
   
  Quote: 





subsequence said:


> Are you kidding me?


----------



## grokit

It only works if you use water that has been distilled, edit: _denatured_, at a sub-atomic level.


----------



## Subsequence

Quote: 





el_doug said:


> I guess the fact that it's a joke went right over your head?


 
  Honestly sometimes it's hard to tell with this stuff. But i will blame it on my friend alchohol since he doesn't mind(he will just get payback later).


----------



## Griploc

I will have my usb cable in a couple more weeks... I can reasure you all this will not be a garden hose...


----------



## hifuguy

Hi Guys... just my experiences and $0.02. I've been doing electronics since I was 10, have an EE degree, have been making a living in electronics for 30 years and have been an Audiophile for about 35 years. The brain suggests that bits are bits and the USB cable shouldn't matter. Real world experiences  and my ears tell me just the opposite, and it's not subtle, at least with my system and my ears. It's difficult to explain the reason as to why this is so from an electronics/physics standpoint. My guess is that it's mainly an issue with timing/jitter and perhaps isolation of the power lines from the data lines. The jitter issue is a difficult-to-explain and complex relationship of micro-vibration, dilectrics, conductor type and geometry. To this day, my brain says this doesn't really make any logical sense. My ears tell me the exact opposite. In the end, my ears won the debate hands down.Going back to a standard USB cable robs my system of the that magic make makes you forget that you're listening to just another good stereo. It all started with a Locus Design Polestar and then I upgraded to a Locus Design Axis, using Audirvana Plus, a Mac Mini and a Wyrd4Sound DAC2. I miss Lee Weiland... he was a cable genius,  a gentleman and an awesome guy. Whatever the secrets of USB cables really are, I think he knew most them. All of this being said, if you can't hear the difference, that's OK. Then USB cables are a non-issue for you. It really boils down to what you do or don't hear. If you try a good USB cable and you can't hear the difference, then that's that. On the other hand, if you do hear it, then it becomes of case of, "Is it worth it or not". Pretty simple really. If you haven't tried it in a nicely controlled experiment, then your opinion is nothing more, nothing less than a best guess. It doesn't take DBT. If it's that subtle, then it's not worth it to me. I've demonstrated the difference to four friends. They all heard the difference, and had a bewildered look, in about 30 seconds of listening. In my system at least, the difference is anything but subtle. You millage may vary and probably will. Again, this is just my $0.02... the last thing I'm looking for is a fight. I'm just trying to share my experience with you guys in the hopes that the music you love can become (even more) alive. Happy listening and happy experimenting everyone! High-end audio is awesome!


----------



## Griploc

I hope i hear a difference
But you have probably opened a can of worms, lol.


----------



## bigshot

I think jitter and timing is a convenient theory to explain every non-verifiable subjective impression. I'm beginning to read it as a synonym for "imagined".


----------



## Citan

So hifuguy, you and your friends could not only pick out the different cables blind, but could also come to a consensus of which sounded better (without knowing in advance which was which)?


----------



## nick_charles

Quote: 





hifuguy said:


> Hi Guys... just my experiences and $0.02. I've been doing electronics since I was 10, have an EE degree, have been making a living in electronics for 30 years and have been an Audiophile for about 35 years. The brain suggests that bits are bits and the USB cable shouldn't matter. Real world experiences  and my ears tell me just the opposite, and it's not subtle, at least with my system and my ears. It's difficult to explain the reason as to why this is so from an electronics/physics standpoint. My guess is that it's mainly an issue with timing/jitter and perhaps isolation of the power lines from the data lines. The jitter issue is a difficult-to-explain and complex relationship of micro-vibration, dilectrics, conductor type and geometry. To this day, my brain says this doesn't really make any logical sense. My ears tell me the exact opposite. In the end, my ears won the debate hands down.Going back to a standard USB cable robs my system of the that magic make makes you forget that you're listening to just another good stereo. It all started with a Locus Design Polestar and then I upgraded to a Locus Design Axis, using Audirvana Plus, a Mac Mini and a Wyrd4Sound DAC2. I miss Lee Weiland... he was a cable genius,  a gentleman and an awesome guy. Whatever the secrets of USB cables really are, I think he knew most them. All of this being said, if you can't hear the difference, that's OK. Then USB cables are a non-issue for you. It really boils down to what you do or don't hear. If you try a good USB cable and you can't hear the difference, then that's that. On the other hand, if you do hear it, then it becomes of case of, "Is it worth it or not". Pretty simple really. If you haven't tried it in a nicely controlled experiment, then your opinion is nothing more, nothing less than a best guess. It doesn't take DBT. If it's that subtle, then it's not worth it to me. I've demonstrated the difference to four friends. They all heard the difference, and had a bewildered look, in about 30 seconds of listening. In my system at least, the difference is anything but subtle. You millage may vary and probably will. Again, this is just my $0.02... the last thing I'm looking for is a fight. I'm just trying to share my experience with you guys in the hopes that the music you love can become (even more) alive. Happy listening and happy experimenting everyone! High-end audio is awesome!


 
   
  There have been a few credible studies of jitter audibility involving DBT and controlled levels of jitter both random and deterministic. To date the level of jitter that creates verifiably audible distortion is approximately 2 levels of magnitude higher than that found in generally competent digital components - viz there is no rigorous study that indicates that jitter is normally an issue.  
   
  As for your cable experiments, these are uncontrolled sighted listening tests prone to all sorts of human biases and of zero value in this subforum, this is the one subforum where we are allowed to request a higher level of evidence and anecdotes ("now just listen to this cable") such as you recount are simply insufficient for that purpose.


----------



## dvw

I have a few questions on jitter on USB cable that people attributed to in audio.
   
  1. If jitter is caused by the cable, this means the DAC's local clock must be synchronous to the transmit clock. USB 1.0 is 1.5Mbit/s and 2.0 is 480Mbit/s. The audio clock is 44KHz. How does this translate?
  2. If the local clock is indeed synchronous to the USB clock, what about the tolerance of the clock? Won't that change the audio playing at all? In this I mean if the recording is done at 43KHz sampling and the derived clock from the USB clock is at 45KHz, won't that be more detrimental.
  3. What if I am streaming audio, what is the local clock synchronous to?
  4. How does jitter change the value of a stream so you'll better highs and lows? Do I have to worry about my banking transaction if that indeed is the case.
  5. What does jitter sounds like?


----------



## bigshot

Number 5 assumes that jitter is audible. In the real world, it isn't.


----------



## dvw

Quote: 





bigshot said:


> Number 5 assumes that jitter is audible. In the real world, it isn't.


 
  Yes, but people that claim jitter is the cause of quality degradation never describe the sound. There is a theoretical sound and it ain't grainy high and smaller soundstage.


----------



## bigshot

I had one stereo salesman describe it to me as a buzzing vibration in the sound. As if someone could possibly detect picoseconds as discrete bumps in a vibration pattern!


----------



## anetode

It sounds like there are a bunch of ants crawling around in your Stax.


----------



## hifuguy

Hi Guys.... there really is no question in my mind, the high-end Locus Design (yeah, expensive) USB cables just sounds way better in many of the usual audiophile terms (that get kind of tedious sometimes), but the bottom-line is that it makes me forget it's just a very good stereo. With the fancy-pants USB cable It is able to transcend that and make you feel like you are at the musical event (at least on better recordings). Going back to a regular USB cable makes you feel like you're missing the magic. I really wish I could say why with authority, but other than the items discussed previously, I can't explain it in a proof that cable skeptics can/will accept. On one hand, If you have tried this experiement on a good system, but you can't hear it, then anything anyone says about it doesn't matter... it's simply not your reality and that's just fine. One the other hand, at least with the system that I have, I can assure you that I could pick it out every time.... I'll bet many (most?) you could too. I only bother to write all of the this because the addition of the USB cable really raised my level of musical enjoyment, and I wanted to share it with others. Also I should note, that I have a data sample of two! The Locus Design Polestar and Axis. I can only vouch for these two, as they are the only ones that I have personally heard. I can appreciate the very nature of this forum seeking to merge signal propagation theory with the art of real-world audio cable production... it would be swell if they match-up. If they did, then the suggestion would be that we know every nuance of how it works. But the logic of suggesting that if you can't measure it, can't explain it then it can't be possibly be true or of musical value to our hobby and our love of music escapes me. I think I'm going to go away now. Thanks for reading. Keep an open mind and give it a real try. Happy listening and all the best.


----------



## ultrabike

What are you using as your source, DAC, Amp, and transducers in your rig?


----------



## bigshot

Wires are not capable of transmitting magic, even high end ones.

As for all USB cables sounding the same, yes that is my reality. I try to live in reality and not stray too far from it.


----------



## hifuguy

Hi Ultrabike, Et All,
   
  Ha... well, it's a bit unusual. I should probably write it up in some other forum sometime. As I noted, I've been an audiophile for about 4 decades. But up until recently, I've never really been content and happy. Up until now, I had always took the typical approach, source (CD or DAC), amplification (preamp+amp or integrated) and then the speakers. But  no longer. I've now been very happy for quite some time with the following layout... it regularly trancends being just a good stereo and carries me away. Here's how it looks....
   
  Mac Mini - Audirvana Plus Music Player SW - (then the ever-ontroversial Locus Design USB cable!) - Wyrd4Sound DAC2 - Dynaudio BM5a Monitors.
   
  So, the Dynaudios are of a pro audio linage, often finding themselves in recording studios. My twist with them is that they are not on stands. Instead, I admit to stealing an the idea from Mapleshade of putting them close to the floor, on a thick maple blocks. Being kind of cheap, I made them myself. The maple blocks are brass spiked to the sub-floor with 3 long spikes. On the top front of a wooden base is a very tall fourth brass spike that tips the front of the speaker way up. The plane created by the top of the speaker crosses the top of my head in my listening position. The speakers are brought well out into the room. They don't like being near a wall. The volume control is handled by the DAC2, and its remote control. You would think that the soundstage would burry itself into the floor, but it doesn't. Instead it amazing floats up above them and is incredibly deep and wide. It's awesome. The bass is solid and lightening fast.... I think it likes the boundry reinforcement off the floor. For what it worth, I've now seen two people come over and hear it and then go out and recreate the system identically in their homes because they fell so in love with it. That's pretty high praise. It really is that good. BM5a can be found on ebay for about 700-800. Not bad for a speaker and a power amplifier! BTW, each speaker has two 50 watt power amps, one for the tweeter and one for the woofer. The crossover is done in the low-level electronics domain... rather than the usual large high-power inductors and capacitors at the drivers. Thanks for asking.... I'm so happy with it. Send me a PM if you would like to know more. I don't even think about upgrading the basic pieces anymore.


----------



## ultrabike

Your rig does seem fairly decent, and therefore I'm a bit surprised that you can hear differences with the Locus Design USB cable vs a regular standards compliant one. Do they provide packet error rate performance numbers vs their competitors?
   
  For me, jitter is not too hard to understand. It's sort of low level FM modulated noise into a signal. I'm not that well versed on USB protocols, but from what I've read a USB receiver requires buffers and some clock recovery or re-clocking scheme (depending on USB operaton mode) to remove jitter from the chain and from the fact that data arrives in packets which need to have their control data and packet-to-packet time gaps removed. Errors resulting from jitter should be minimal if using a decent DAC with a decent USB receiver. That is why I'm a bit surprised your cable makes such a big difference.


----------



## bigshot

I'm betting your speakers are what make your system sound good. And yes, you always want speakers on the floor. The bass speaker uses the plane of the floor.


----------



## Lorspeaker

i heard a LOCUS DESIGN usb before...way to expensive for me to own it.
  But the soundstage, especially the depth was astonishing. i bet hifiguy's speakers sounded like it came thru the back wall.





   
  Now i settled for a double whammy...a LAT usb(left of pic) to my dac...and a Furutech usb(right) to my portable diskdrive.
  I wouldnt dare say this combo beats the LOCUS....but its almooooooost there. I know its logically crazy to put one on the diskdrive...but it works for my ears.
   
  cheers guys....


----------



## bigshot

I have a $120 Sony bluray player. I bet it sounds just as good as all that gear.


----------



## hifuguy

Hi Lorspeaker...
  Actually, you have touched upon one of my favorite aspects of it... image depth is one of my favorite hot buttons and its one of the aspects of high-end audio that I enjoy the most. It's so amazing that so many people don't even know it's possible. When the Dynaudio's are brought way out into the room, their image depth is just jaw-dropping fun. Soundstage recreation is such a major part of the illusion. If I put them back near the rear wall, they still sound good, but it goes back to being just a good stereo. So that's one of the nice things about the BM5a... they are so small and easy to move. My listening room is also our family room. So I'm happy and my wife is happy. I know this sounds a bit crazy, but I'd put it all up against just about any system and it would hold it's own. I go and visit hi-fi stores with the really high priced stuff and I leave with a (smug) smile, thinking that I have stumbled upon an affordable magic formula, though some thinking, some research and yes, some blind luck. Happy Listening. Here's a picture... the speaker is only 12" tall! I guess it would be best if I stop derailing this USB thread with speaker stuff. PM me if you have any questions and sorry, about the picture being in the wrong orientation. happy Listening!


----------



## bigshot

What you're calling "image depth" actually has a name... coupling. You never want to push your speakers up close to the wall, no matter what your wife says, or your speaker will couple with the wall, and you'll be hearing the effect of the wall more than the speaker. In order for a speaker to push sound out beyond itself, it has to be freestanding.

You do want the speaker to couple with the floor so it pushes the bass out in a straight line along the floor and doesn't bounce around too much. Never raise bass speakers up to face level or tilt them up at a sharp angle. They have to be low. Bass gets muddled pretty easy if it starts bouncing between the floor and ceiling. It should flow along the floor like water and fill the room.

Also, you want your two main speakers close together. No more than six to eight feet apart. The two channels need to couple together to form a complete left/right soundstage. Otherwise, they'll function separately and you'll get the "rechannelled for stereo" early Beatles sound. This is probably the most common mistake speaker newbies make. Keep 'em close!

This is all speaker room placement 101. It applies the same for inexpensive speakers the same as it does fancy ones. Like guitars, a lot of speakers sound good at low volumes. It's how they perform at peak listening level that separates the men from the boys.

When I demo my system for friends and play something like Marche Slav, or other pieces that start out quiet and end up with a devastating brass fortissimo, they always start out smiling and nodding... Then the blast hits and their jaws drop open and they utter the name of one of this forum's sponsors... "Holy Schiit!"

Really good speakers hold back when they need to. They don't produce bass or treble unless it's in the music, and they sound as good at 1/4 volume as full blast. Music should be able to sneak up on you with sound you aren't expecting because it hasn't come up in the timbre of the music yet. I don't know if I can explain that concept well in words. When you hear it, you understand.


----------



## bigshot

One interesting historical note on coupling...

In the users' manual for the Victor Victrola, it said to put the phonograph in the corner of a low ceilinged room for best sound. Acoustic records had very little bass to mess up with reflections caused by coupling. However the horn of the phonograph was about chest high, so coupling wth the floor, walls and ceiling in the corner of the room effectively extended the length of the horn, increasing bass.

It also focused the sound to shoot straight out of the horn, projecting a dimensional aural image about eight feet in front of the phonograph. If you play a Caruso record on a good Victrola well placed in a room, the phonograph is in the corner, but Caruso's voice comes from the center of the room. It's an uncanny experience and it can make the hair on the back of your neck stand up.


----------



## ultrabike

Quote: 





hifuguy said:


> Hi Lorspeaker...
> Actually, you have touched upon one of my favorite aspects of it... image depth is one of my favorite hot buttons and its one of the aspects of high-end audio that I enjoy the most. It's so amazing that so many people don't even know it's possible. When the Dynaudio's are brought way out into the room, their image depth is just jaw-dropping fun. Soundstage recreation is such a major part of the illusion. If I put them back near the rear wall, they still sound good, but it goes back to being just a good stereo. So that's one of the nice things about the BM5a... they are so small and easy to move. My listening room is also our family room. So I'm happy and my wife is happy. I know this sounds a bit crazy, but I'd put it all up against just about any system and it would hold it's own. I go and visit hi-fi stores with the really high priced stuff and I leave with a (smug) smile, thinking that I have stumbled upon an affordable magic formula, though some thinking, some research and yes, some blind luck. Happy Listening. Here's a picture... the speaker is only 12" tall!


 
   
  Those are nice speakers dude! Do you have a subwoofer to go along with them? Have you heard the Mackie HR624s? They seem to be well regarded as well.


----------



## paradoxper

Quote: 





lorspeaker said:


> i heard a LOCUS DESIGN usb before...way to expensive for me to own it.
> But the soundstage, especially the depth was astonishing. i bet hifiguy's speakers sounded like it came thru the back wall.
> 
> 
> ...


 
  Which Locus cable? I might be picking up one of these and maybe getting the USB cable LFF has been reviewing. NDA doesn't permit him
  to share any details on the cable. haha


----------



## Lorspeaker

wow its only *12*inches short....????  did u get the subwoofer too? 
  the dynaudio is an enclosed box right? not ported? i might sell my rig and just get this tiny thunderbolt. 
  i love softdome tweeters.  thanks for the heads up..will read more into this.
   
   
  ============
   
  i think he is referring to this...
  http://www.locus-design.com/index.php/axis-usb-cable


----------



## Lorspeaker

Quote: 





bigshot said:


> I have a $120 Sony bluray player. I bet it sounds just as good as all that gear.


 
   
  given your knowledge of acoustic alchemy...i bet u can create something beautiful out of that bluray...bypassing all the usb stuff.
  i have an old thomson dvd player


----------



## ultrabike

Quote: 





lorspeaker said:


> i think he is referring to this...
> http://www.locus-design.com/index.php/axis-usb-cable


 
   
  Yup, the same makers of the* $3549 3ft *Cynosure v2 USB cable, made out of "_carbon fiber, cotton, SPC braid, ERS fabric, Nylon, Teflon, and many more_" stuff. From their website, said cables are damped from mechanical vibrations. Their cables are terminated with the "_best Mundorf solder_" and some "_special adhesive_." Said cables are also "_CryoFreeze process_" treated. And they also "_wasted more money than_" they want "_to think about teaching_" their vendor partners "_to make the wire exactly like" they "want it made_."
   
  Kid you not: http://www.locus-design.com/index.php/cynosure-usb-cable
   
  That said, I don't think their cable is thick enough or long enough to satisfy most usb ports.


----------



## paradoxper

Quote: 





ultrabike said:


> Yup, the same makers of the* $3549 3ft *Cynosure v2 USB cable, made out of "_carbon fiber, cotton, SPC braid, ERS fabric, Nylon, Teflon, and many more_" stuff. From their website, said cables are damped from mechanical vibrations. Their cables are terminated with the "_best Mundorf solder_" and some "_special adhesive_." Said cables are also "_CryoFreeze process_" treated. And they also "_wasted more money than_" they want "_to think about teaching_" their vendor partners "_to make the wire exactly like" they "want it made_."
> 
> Kid you not: http://www.locus-design.com/index.php/cynosure-usb-cable
> 
> That said, I don't think their cable is thick enough or long enough to satisfy most usb ports.


 
  Sometimes I wish they would leave out the marketing crap and just list the specs and price. But I'm always interested
  when people say they hear a difference between cables, be it subtle or "night and day."


----------



## Lorspeaker

faintzz.....my absolute ceiling budget is usd100 bucks for a usb....n rcas....just wanna get off the stockcrabwire....and float alittle higher...
  but 3549...................................................................................thats thats....... fill in your own words here.
   
  but it will make sense if your speakers are usd100,000 a pair.


----------



## bigshot

The speakers can cost a million dollars and a $3800 USB cable is still gonna sound like one from Monoprice


----------



## ultrabike

Quote: 





lorspeaker said:


> faintzz.....my absolute ceiling budget is usd100 bucks for a usb....n rcas....just wanna get off the stockcrabwire....and float alittle higher...
> but 3549...................................................................................thats thats....... fill in your own words here.
> 
> but* it will make sense if your speakers are usd100,000 a pair*.


 
   
  Yeah, my bad. I left out that their Cynosure v2 USB cable is made out off "_ultra pure CFDCT-UP-OCC-Ag conductors_." And if for whatever "_odd reason_" the USB cable "_does not perform as expected in your system. A 20% restocking fee (of the total price) will be charged and any shipping charges incurred will be the responsibility of the buyer. In order to be eligible for return, the cable must be 'in' new condition (this condition will be evaluated by_" himself/herself "_, i.e." He/She "will be the judge)._"
   
  Now how is that for customer service! Take that Monoprice & Radio Shack!


----------



## Lorspeaker

Quote: 





bigshot said:


> The speakers can cost a million dollars and a $3800 USB cable is still gonna sound like one from Monoprice


 
   
  but of cos....when the power switch is OFF.


----------



## ultrabike

Quote: 





lorspeaker said:


> but of cos....when the power switch is OFF.


 
   And when the power switch is ON, be prepared to feel the might of CFDCT-UP-OCC-Ag!


----------



## ultrabike

The following paper relates to RCA cable interconnects more than USB cables. It compares > $100 cables and ~ $10 cables. I would recommend to at least read the last paragraph on page 41:
   
http://dspace.mit.edu/bitstream/handle/1721.1/46225/41567257.pdf
   
  Hope this is useful.


----------



## Lorspeaker

back to earth....i am seriously considering snagging a wireworld usb cable...(within my usd100)
  the powercord i had was amazingly detailed and airy on my setup...vs my other wires. 
  http://www.wireworldcable.com/categories/usb_cables.html
  http://www.apolloa-v.com/servlet/the-178/wireworld-starlight-usb-cable/Detail


----------



## LFF

Quote: 





ultrabike said:


> The following paper relates to RCA cable interconnects more than USB cables. It compares > $100 cables and ~ $10 cables. I would recommend to at least read the last paragraph on page 41:
> 
> http://dspace.mit.edu/bitstream/handle/1721.1/46225/41567257.pdf
> 
> Hope this is useful.


 

 BS...these people are obviously biased towards science and are not audiophiles. They are researchers!


----------



## ultrabike

Quote: 





lff said:


> BS...these people are obviously biased towards science and are not audiophiles. They are researchers!


 
   
  Dude, you are right! The paper was done to partially fulfill the requirements for a BS degree!


----------



## kskwerl

lff said:


> Quote:
> 
> 
> 
> ...




Nice find LFF

Sent from my SCH-I535 using Tapatalk 2


----------



## Lorspeaker

...tats....tats.... 1998 
   
  it could be true,  way back then
   
  but since then
   
  we have landed on mars...?
   




   
   
  yes...wireworld...usb3....deliciousssss.


----------



## ultrabike

Quote: 





lorspeaker said:


> ...tats....tats.... 1998
> 
> it could be true,  way back then
> 
> ...


 
   
  mars... usb cables... 
	

	
	
		
		

		
		
	


	




 Yup, I feel the magic, I think you've got something there.


----------



## drez

Quote: 





bigshot said:


> Number 5 assumes that jitter is audible. In the real world, it isn't.


 
   
  What is the real world?  Is the limit of what is real defined by current scientific research - ie everything that can be known is already known?  This is a position of philosophy and not of science.  My personal anecdotal experience over numerous iterations is that the performance of digital transports affects audio reproduction, and numerous other people have similar anecdotal experiences.  In my opinion of existing experimental data does not show low levels of jitter to be audible, the experimentation is clearly flawed in some way from my perspective.  One reality cannot disprove or prove another reality, it can merely attempt to guess at what is happening in this other reality.  
   
  To put it another way - One can point to a certain experiment testing the audibility and say "this is reality", or point to the magnitude of the distortion which a level of jitter will produce and say that this is below a threshold of audibility and say "this is reality" but in reality both of these are artificial analogues of reality and not reality itself.  Experiments are attempts to dismantle, reproduce and reconfigure reality, and are in this sense abstract and not ordinary or typical scenario.
   
  Take for example a chair is in a room - while you are in the room you can perceive it with your senses, but once you leave this room you can no longer directly perceive the chair with your senses.  Is the chair still in the room?  Thieves might have broken in and stolen the chair and then returned it, or it might have spontaneously combusted and rematerialised for all you know.  What if another person was still in the room and said that aliens appeared and abducted the chair while you were out of the room.  Can you prove that this was not real?  You can create another room and a chair, bring in a second person and say "look this second person did not see the chair be abducted by aliens."  Maybe you could say "the room was too dark to see what was happening clearly" or "the chair was too big to be taken out of the room so it is impossible".  Perhaps you can construct an experiment with cameras in the room to show that the chair was in fact not taken from the room by aliens and therefore claim that the first instance was invalid?  Maybe you can repeat this experiment a thousand times over with the cameras and therefore declare that the chair cannot be removed from the room by aliens?  No amount of repetition or permutation of experimentation will provide evidence that in the first instance the chair was not taken out of the room by aliens.
   
  For too often the line I see clung to is that there is some onus on the casual observer to provide evidence, because science has insurmountable evidence which is contrary to what they are observing.  My point from the above is to put into perspective what is being argued, and to show that there are practical limits on what we can declare to be real or not real, and limits also in the methods we might use to go about doing this.  One could do a blind test and get a negative result and still oneI can not prove that what someone else claims to have observed was not real or a valid observation.  At most one can claim that my observation was more credible because one took steps to recreate an artificial scenario which attempts to exclude certain problematic influences.  In other words "My experience does not match what you are observing, but I consider my methods of observation of similar but not identical phenomenon, along with the scientific theories  and observations of similar but not identical scenarios to be more reliable, therefore I do not consider your observation valid at this point."
   
  If we return for a moment to the OP's original post however:
   
  "Dare I put my toes into the water? I'm a physicist and audiophile (establish credibility!). I've been into living room system audiophilia for 20 years. This pc-audio is new to me and I'm just starting up. Now, about USB cables: I can hear a small difference between cables. If we assume the bits are transferred properly (and there is some debate  about that in USB-audio vs. USB-data), I think the issue is electromagnetic nosie getting through the circuits and into, in my case, the headphone amplier. All EM noise is immediately spread through an entire system, end-to end. Since at the end of the day, something is converted to analog to hear it, the cleaner the power and the better the shielding, the cleaner the final D/A will be. This will not be anything that affects data transfer, per se. All billion TB of information can be transferred with perfect fidelity; when you open your word document, all the correct words are there. But we don't listen to data files. There has to be analog conversion somewhere. In my living room system, it was always well worth the effort to clean up the power and have well shielded cables. Do any of the audiophile USB cables actually provide effective power filtering and shielding, such that the headphone amp is cleaner even though connected to the PC? I don't know. This can be properly done in a living room system. But there are snake-oil produccts there too, of course."
   
  I see no need to delve into challenges of what is real and what is not real - or for some people what has evidence and what does not have evidence.  This would be counterproductive at any rate as nobody likes being told what they are or are not perceiving, and the discussion does not go anywhere.  My response to this question would be as follows:
   
  There are several possible explanations for the difference you claim to have heard:
   
  1)Jitter performance of the cable.
  2)Noise or interference creeping through the DAC.
  3)You were mistaken in hearing a difference.
  4)Some as yet unknown magical influence.
   
  You may take your pick, but there is no evidence to prove any of these decisively at this point IMO.  Here is some food for thought:


----------



## ultrabike




----------



## hifuguy

Hi Everyone (again),
   
  I don't run a subwoofer with my BM5A and am fully satisfied on the bass side. I'm not a bass head, but I like solid, tunefull, tight bass as much as the next guy. I borrowed a subwoofer once, and decided that the pros versus cons were not worth it to me. Placing them and adjusting them isn't child's play, especially when the Dynaudio bass is so lightning fast. The Dynaudio's on the floor are amazingly satisfying. They don't go down real deep obviously, but they really like hanging out on the floor and meet my requirments for bass and are more than satisfying to me all by themselves.
   
  Can we please stop going around and around with the USB cables all sound like they came from Monoprice thing. I don't believe that is true and saying the same thing 10 times doesn't change anything. That is what I believe.... It is what I have experienced and tried first-hand. I you think USB cables all sound the same, then that's fine. Have you tried a good USB cable? If so and you found no difference, the perhaps it's your system, perhaps it is your ears, perhaps you can't rationalize it to be possible. Believe me, I get that it is really hard to comprehend. I'm thinking that there should be a new rule in the cable forum. If you have not heard first-hand what you are writing about then you should have to say that so everyone knowswhat you basing your comment upon, and on top of that you should probably think two or three times before writing any opinions at all. I'm not trying to be difficult, but how else can you know. The transmission of the one-and-zeros for high-end computer based audio is much more complex, much more subtle and much more important than it appears on the surface. I guess that's all from me. I've had my say on the debate. I was just trying to share my experiences of what made my system sing so that yours can too. I think most people who have invested into a reasonably good computer-based audio system will be happy they tried it. If not, just send it back. You have nothing to loose. Happy Listening


----------



## TickleMeElmo

Quote: 





hifuguy said:


> Hi Everyone (again),
> 
> I don't run a subwoofer with my BM5A and am fully satisfied on the bass side. I'm not a bass head, but I like solid, tunefull, tight bass as much as the next guy. I borrowed a subwoofer once, and decided that the pros versus cons were not worth it to me. Placing them and adjusting them isn't child's play, especially when the Dynaudio bass is so lightning fast. The Dynaudio's on the floor are amazingly satisfying. They don't go down real deep obviously, but they really like hanging out on the floor and meet my requirments for bass and are more than satisfying to me all by themselves.
> 
> Can we please stop going around and around with the USB cables all sound like they came from Monoprice thing. I don't believe that is true and saying the same thing 10 times doesn't change anything. That is what I believe.... It is what I have experienced and tried first-hand. I you think USB cables all sound the same, then that's fine. Have you tried a good USB cable? If so and you found no difference, the perhaps it's your system, perhaps it is your ears, perhaps you can't rationalize it to be possible. Believe me, I get that it is really hard to comprehend. I'm thinking that there should be a new rule in the cable forum. If you have not heard first-hand what you are writing about then you should have to say that so everyone knowswhat you basing your comment upon, and on top of that you should probably think two or three times before writing any opinions at all. I'm not trying to be difficult, but how else can you know. The transmission of the one-and-zeros for high-end computer based audio is much more complex, much more subtle and much more important than it appears on the surface. I guess that's all from me. I've had my say on the debate. I was just trying to share my experiences of what made my system sing so that yours can too. I think most people who have invested into a reasonably good computer-based audio system will be happy they tried it. If not, just send it back. You have nothing to loose. Happy Listening


 
   
  You do know there is something called science that overrides what you "feel"? It's not that we THINK that all USB cables sound the same, it is because binary data transmission and associated CRC protocols are the foundation of computer science. To deny what is correct is to admit that there is a magical element to computers that is beyond our comprehension.
   
  I have not tried a "good" USB cable and there is no point in trying a USB cable. The onus is on the party saying it does make a difference to prove the validity of his or her statement. If it can be proved (and it has) that any functional USB cable is equivalent to any other for transferring data (and that is all that a USB cable does), then the responsibility is for others to prove that there is a measurable difference resulting from use of a "better" cable. By your logic there is a point to trying to jump to escape the earth's orbit because there is no harm in not doing it. That line of reasoning is vacuous at best.
   
  The transmission of 1's and 0's is extremely well understood, there is no mysticism. There is no subtlety in methods of applying fourier transforms to sinusoidual waveforms to approximate square waveforms. Nor is there any subtlety in the fact that USB has a raw error rate of less than 10E-9. With 14000kbps (about what lossless 16/44.1 audio comes out to) and at an effective transmission rate of about 240mbps (after overhead) that is one raw error on average per TWO minutes. With error correction the error rate is for all intents and purposes ZERO.
   
  The fact that you think that USB cables make a difference lends about as much credence as the homeopath telling the terminal cancer patient that her special treatment can cure her. It is no different than the lady who won the lottery and thinks that "7" is her lucky number.


----------



## drez

Quote: 





ticklemeelmo said:


> You do know there is something called science that overrides what you "feel"? It's not that we THINK that all USB cables sound the same, it is because binary data transmission and associated CRC protocols are the foundation of computer science. To deny what is correct is to admit that there is a magical element to computers that is beyond our comprehension.
> 
> I have not tried a "good" USB cable and there is no point in trying a USB cable. The onus is on the party saying it does make a difference to prove the validity of his or her statement. If it can be proved (and it has) that any functional USB cable is equivalent to any other for transferring data (and that is all that a USB cable does), then the responsibility is for others to prove that there is a measurable difference resulting from use of a "better" cable. By your logic there is a point to trying to jump to escape the earth's orbit because there is no harm in not doing it. That line of reasoning is vacuous at best.
> 
> ...


 
   
  Data transmission over USB and the way in which A DAC streams audio from a computer are different.  Data transfer uses bulk mode which does not care about the timing at all.  Cheaper USB transports and DAC chips use adaptive transfer mode in which the USB receiver is reveives the clock from the computer, and attempts to fix any timing errors (jitter).  Some more recent or expensive USB transports use asynchronous tranfer where the USB device controls the rate at which the packets are tranfers with it's own clock, usually with some sort of buffer to attempt to ensure that if a packet is not sent in time the stream is not interrupted.  The Hiface uses bulk mode transfer which in theory means packets can be resent if they are not received correctly.  Bear with me if I have not described things correctly.
   
  Some USB transports draw power from the USB port, so the cable may contribute the the rective impedance of the power being supplied, or pick up noise from the surroundings, or crosstalk between the conductors.  Most USB cables are effective enough to ensure that non-timing critical transfer modes work without error.  At this point people who beleive they can predict how equipment will behave for whatever reason will say "but asynchronous USB is buffered to compensate for variation in the latency between when when the USB transports requests a packet and when it arrives, and they are correct in theory.  In practice things are not that simple in my experience and you may feel free to take my experience with a grain of salt if you think you know everything there is to know about digital audio.
   
  Me personally I know enough to know that I in fact do not understand everything to do with digital audio, and to trust my ears and judgement instead of my limited understanding of the technologies at hand, or what studies I have not actually closely studies might be used to make claims about what will or will not affect sound quality.


----------



## Lorspeaker

dang, jusr realised my mcbook air doesnt hv usb3......


----------



## bigshot

drez said:


> What is the real world?




"Real World" is what human beings can actually hear.

Welcome to Sound Science. Sorry about your misconceptions.


----------



## bigshot

hifuguy said:


> Hi Everyone (again),
> 
> I don't run a subwoofer with my BM5A and am fully satisfied on the bass side. I'm not a bass head, but I like solid, tunefull, tight bass as much as the next guy. I borrowed a subwoofer once, and decided that the pros versus cons were not worth it to me. Placing them and adjusting them isn't child's play,
> 
> Can we please stop going around and around with the USB cables all sound like they came from Monoprice thing. I don't believe that is true and saying the same thing 10 times doesn't change anything. That is what I believe...




You shouldn't dismiss subwoofers entirely. The setup on them can be a little complicated, but it's totally worth the trouble. Especially with smallish mains like the ones you have. The trick is that the lower a speaker goes, the more power it requires and the more expensive it is to get a good one. The Pieso supertweeters in my system cost $50 for the pair, and they spit out oodles of clean, loud super high frequency sound. But my Sunfire subwoofer cost thousands. But the ability to have a smooth response below 100Hz makes a LOT of difference. The bass carries a lot of the rhythm and fills up a room with sound. It's actually more important than the treble.

As for saying all USB cables sound the same... You're right that me simply repeating the truth over and over isn't going to change your mind. The way for you to change what you believe is to take the time and trouble to set up a nice level matched blind comparison. When you spend $100 on a wire that comes with your hard drives for free, there is a huge temptation to justify the expense to yourself by convincing yourself it sounds better. Just like you've convinced yourself that a subwoofer won't improve your speaker system. But it isn't true. It's perfectly fine to spend big money on simple wires if you have a c note to burn and you really like the color of the insulation on the fancy cable. But it doesn't make any difference to the sound at all. Not even a little bit.

It is very easy to make wires in China. If high end cable manufacturers had really stumbled across a scientific breakthrough in cable design, it wouldn't take two weeks for the five dollar Chinese knock offs to arrive at the Port of Los Angeles and do the exact same thing for pennies.


----------



## bigshot

drez said:


> Me personally I know enough to know that I in fact do not understand everything to do with digital audio, and to trust my ears and judgement instead of my limited understanding of the technologies at hand, or what studies I have not actually closely studies might be used to make claims about what will or will not affect sound quality.




Based on your comments, it's clear that you'va actually invested a lot of your time absorbing papers on this subject... But the problem is, it's the papers written by high end cable manufacturers to justify buying their products. And those papers leave out the simplest and most meaningful data of all...

What is the size of the error relative to a natural benchmark we can understand?
And what is the generally accepted threshold of audibility?

Jitter is generally measured in picoseconds. Now the average person has no clue how big a picosecond is. A little googling will answer that. Try to imagine the difference in scale between 24 frames a second in film, or how far a car will travel in a picosecond if it's going 100 miles an hour. Or even the speed of sound, or a bullet being fired from a gun. It's actually a fun little exercise and you'll learn something about time. Once your head is wrapped around how *infinitessimally small* the errors we're talking about really are, it isn't that much of a leap to realize that this stuff *just does not matter*.

Jitter is a marketing ploy. It isn't a measure of sound quality.


----------



## bigshot

lorspeaker said:


> dang, jusr realised my mcbook air doesnt hv usb3.




It doesn't need it for this. You have optical out.


----------



## liamstrain

Also, USB 2 is quite robust, if you don't want to use the optical.


----------



## bigshot

The big problem I've found with optical is that it's a bit delicate. Optical cables don't work well with kinks. Better for installation in fixed systems than portable.


----------



## Citan

Quote: 





bigshot said:


> "Real World" is what human beings can actually hear.
> *Welcome to Sound Science. Sorry about your misconceptions.*


 
  Gold.


----------



## LFF

Quote: 





ultrabike said:


> Dude, you are right! The paper was done to partially fulfill the requirements for a BS degree!


 
  See....I TOLD YOU!!! I KNEW IT!!!!


----------



## grokit

USB audio can suffer less from jitter (depending on how it's implemented) than toslink optical audio, but it's more susceptible to line noise. This is why the better USB cables that are made for audio have the power transmission component of the cable broken out or heavily shielded from the data transmission component. The type of USB cable does seem to make a difference to my ears, although I haven't tried to the ridiculous (>$150) high-end ones. This is just what I have noticed from playing around with different DACs and cables, so my findings are 100% unverifiable but that's my experience. I have also noticed improvement using a modest real glass toslink cable compared to a cheap plastic toslink cable when using optical.


----------



## bigshot

If you guys don't stop talking about college, I'll show you all my BA!


----------



## grokit

Quote: 





bigshot said:


> Quote:
> 
> 
> 
> ...


 
   
  The Macbook Air does not have the optical/analog combo jack found in all other Macs (except Mac Pro where they are separated), but it does offer HDMI output as an alternative to USB audio.


----------



## bigshot

HDMI is the slickest of all


----------



## dvw

Quote: 





drez said:


> Data transmission over USB and the way in which A DAC streams audio from a computer are different.  Data transfer uses bulk mode which does not care about the timing at all.  Cheaper USB transports and DAC chips use adaptive transfer mode in which the USB receiver is reveives the clock from the computer, and attempts to fix any timing errors (jitter).  Some more recent or expensive USB transports use asynchronous tranfer where the USB device controls the rate at which the packets are tranfers with it's own clock, usually with some sort of buffer to attempt to ensure that if a packet is not sent in time the stream is not interrupted.  The Hiface uses bulk mode transfer which in theory means packets can be resent if they are not received correctly.  Bear with me if I have not described things correctly.
> 
> Some USB transports draw power from the USB port, so the cable may contribute the the rective impedance of the power being supplied, or pick up noise from the surroundings, or crosstalk between the conductors.  Most USB cables are effective enough to ensure that non-timing critical transfer modes work without error.  At this point people who beleive they can predict how equipment will behave for whatever reason will say "but asynchronous USB is buffered to compensate for variation in the latency between when when the USB transports requests a packet and when it arrives, and they are correct in theory.  In practice things are not that simple in my experience and you may feel free to take my experience with a grain of salt if you think you know everything there is to know about digital audio.
> 
> Me personally I know enough to know that I in fact do not understand everything to do with digital audio, and to trust my ears and judgement instead of my limited understanding of the technologies at hand, or what studies I have not actually closely studies might be used to make claims about what will or will not affect sound quality.


 
  So what you are saying is the DAC receives its clock from the computer. How exactly does it work? USB2.0 runs 488MHz and the DAC runs 44KHz. What if I have a USB1 or USB3, won't that really screw up the system?
   
  Let's assume if indeed you get your clock from the computer. Let's say my music is recorded at 43KHz (there will be tolerance and I am exaggerating the difference) and you are running 44KHz. Won't that cause buffer under run?
   
  People are confused by synchronous transmission and synchronous timing. Synchronous transmission is synchronous to a transmit schedule which gurantees bandwidth and latency that's important in real time communication. Synchronous timing refers to clock synchronization which is necessary to recover data.


----------



## dvw

Quote: 





grokit said:


> USB audio can suffer less from jitter (depending on how it's implemented) than toslink optical audio, but it's more susceptible to line noise. This is why the better USB cables that are made for audio have the power transmission component of the cable broken out or heavily shielded from the data transmission component. The type of USB cable does seem to make a difference to my ears, although I haven't tried to the ridiculous (>$150) high-end ones. This is just what I have noticed from playing around with different DACs and cables, so my findings are 100% unverifiable but that's my experience. I have also noticed improvement using a modest real glass toslink cable compared to a cheap plastic toslink cable when using optical.


 
  Wouldn't it be cheaper simply to cut the power line? It might be interesting to DBT a USB cable with and without the power line since they're the same in every other aspect.


----------



## hifuguy

Ya know... I really like you guys, but I think I am going to need some therapy pretty soon.  :-0
   
  Just for fun.... here's a nice hypothetical question for you guys that believe in your hearts-of-hearts that USB cables don't sound better. Please humor me for just a second here... I'm really curious.
   
  What would you say "*IF*" (note the big, and bolded IF).
   
  1 - We all got together at my house... and drank a couple of beers (always a good plan... and maybe a pizza too... I like pepperoni)
  2 - We ran a 100% fully legitimate DBT to you full specifications.
  3 - The result of said DBT was that, "Yes" the high-end USB cable was identified as significantly better every single time. DBT passed with flying colors (remember the IF).
  4 - The beer in step 1 had no influence whatsoever in the results of step 3.
   
  What conclusions and thoughts would you have to say, if this were indeed the result?
   
  And yes, I really do believe in my heart-of-hearts, that on my system, in my living room, on my music, that I really could deliver this result.
   
  But coming back to our individual realities in the real world... I again suggest that unless you have heard a really good cable (Locus Design Polestar and Axis in my case), then I don't think that there is very much that you can tangibly contribute to threads such as this. The same goes for interconnects, speaker cables and power cables. On the other hand, if you really have indeed listened to a specific cable change (USB Cables in the case of this thread), then your experiences (confirming that you can hear improvements or conversely, that you can't) truly are invaluable to the our community and to our understanding of what is worthwhile and what isn't.
   
  If a cable does deliver an improvement, then it becomes a simple question of whether that amount of improvement is worth it to you, as you prioritize your short and long term financial situation and goals. If yes, then buy it; if no, then send it back. It's pretty simple really. Therory is great, but in a thread like this where all of us are really pretty much professional amatures at best, the back and forth theory debates fail to bring much real value to the table in terms of a specif cable being considered is worthwhile (or not). And with that... I'll be at the therapist if you need me any further 
   
  Take Care... Happy Listening!


----------



## AKG240mkII

Clearly, a lot of people know more than you do .
  No, the cable does not have any effect on how warm your zeros and ones sound .
  Your best argument is 'IF' ..


----------



## ultrabike

Quote: 





hifuguy said:


> Ya know... I really like you guys, but I think I am going to need some therapy pretty soon.  :-0
> 
> Just for fun.... here's a nice hypothetical question for you guys that believe in your hearts-of-hearts that USB cables don't sound better. Please humor me for just a second here... I'm really curious.
> 
> ...


 
  I like beer and pizza 
	

	
	
		
		

		
			





. 
   
  The nice thing about USB cable transfers is that due to the discrete nature of the signal, all you need is to verify error rate (since the analog conversion is done down the chain inside the DAC). Do you think running the USB cables in loopback and measuring bit error rate would suffice? Or is that not fair game here?
   
  Say something like this:
http://www.protechdiagnostics.com/usb-loop-back-plugs.htm#
  or this:
http://www.passmark.com/products/usb2loopback.htm


----------



## bigshot

hifuguy said:


> What conclusions and thoughts would you have to say, if this were indeed the result?




I'd run out immediately to see if the design of your cable is patented, because it would probably be even better for magically transmitting data than music.

As for not being qualified to comment on a cable without hearing it yourself, how do you feel about this one...

People are not qualified to speak on ghosts unless they've seen a ghost themself.


----------



## mikeaj

Quote: 





ultrabike said:


> I like beer and pizza
> 
> 
> 
> ...


 
   
  I don't think you can reduce it to BER (well, bits flipped over the channel, prior to coding / retransmission / whatever it does).  People are always going to make a big deal out of the small stuff.
   
   
  If the device is USB bus powered, then surely the cable can be considered part of the power supply in a sense, and it may make some small difference—particularly if the "cable" in question is doing things like including a ferrite bead, rather than just being conductors in a sheath; or if you have a massive source of EMI nearby and you're touting a well-shielded cable.  If the ground, power, or signal lines are not isolated, then some kind of very small effect could couple into the analog parts of the DAC... or even if there is galvanic isolation maybe there could be some effect, and so on.
   
  Note that "some small difference" doesn't necessarily imply a difference that people will pick up.
   
  When the DAC is being clocked by a crystal oscillator, DAC is getting info through I2S or something from the USB receiver (so jitter or other small irregularities on the USB transmission itself are quite isolated from the operation of the DAC), power supply rails are all filtered, some reasonable design standards are applied, it really seems like there shouldn't be much effect from any part of the USB transmission itself, so long as all the data gets there on time.  That's regardless of asynchronous mode or whatever people want to use.  And if there is some effect from the USB transmission, it seems like the active parts of the system, rather than the cable connecting those elements, should have a much larger impact.
   
   
   
   


hifuguy said:


> What would you say "*IF*" (note the big, and bolded IF).
> 
> 1 - We all got together at my house... and drank a couple of beers (always a good plan... and maybe a pizza too... I like pepperoni)
> 2 - We ran a 100% fully legitimate DBT to you full specifications.
> ...


 
   
  DBT can pass with a whole lot less than 100% identification rate, by the way.
   
  Anyway, I'd want to try it again with other USB cables and analyze what's going on with the two that were tested.  I would think that if it actually happened, the most likely explanation would be that one of the two cables is faulty.  Or in the case of one cable doing things like lifting power/ground while the other does not, try again with a lower-end cable of similar functionality, and I'd check the DAC to see if there's any particularly bad susceptibility to whatever.
   
  If everything everybody comes up can't find an explanation (i.e. no faulty cable, checks out in all the other ways) and particularly if these results can be repeated by others, then I would believe it.


----------



## hifuguy

Quote: 





bigshot said:


> What would I say to:





> People are not qualified to speak on ghosts unless they've seen a ghost themself.


 
   
  Interesting question!
   
  In the context of a forum dedicated to gathering the real-world implications and impact of ghosts.... I'd most 100% agree with the premise


----------



## hifuguy

Quote: 





mikeaj said:


> I don't think you can reduce it to BER (well, bits flipped over the channel, prior to coding / retransmission / whatever it does).  People are always going to make a big deal out of the small stuff.
> 
> 
> If the device is USB bus powered, then surely the cable can be considered part of the power supply in a sense, and it may make some small difference—particularly if the "cable" in question is doing things like including a ferrite bead, rather than just being conductors in a sheath; or if you have a massive source of EMI nearby and you're touting a well-shielded cable.  If the ground, power, or signal lines are not isolated, then some kind of very small effect could couple into the analog parts of the DAC... or even if there is galvanic isolation maybe there could be some effect, and so on.
> ...


 
   
  Thanks for your comments... I really liked the last 13 words of your last post. You should give it a try. Pizza arrives in 30 minutes!


----------



## Lorspeaker

everyone has a right to defend his wallet....it really is a pain to touch/buy any branded cable.
  i defintely agree that usb cables wont do any good to your system. pls do not participate in any DBT...
  or sneak a usb home to test.. u will hate yourself. i rather u have peace n bli$$.




   
  but being an addict...i am just sad that the mcbookAir hasnt got a usb3 socket...sobsob.
   
  that wireworld usb3 cable is so gorgeously made...how flat...how intricate inside..oooo...i wonder how it would sound like..
  and it IS less than usd100bucks.oooooooooo...somebody SHOOT me now...save me.




   
  =======================
   
  hey hifiguy....
  i had a REL subwoofer before...quite musical when properly matched to my bookshelf speakers...but my neighbours hated it when the dinosours stomped thru my living room.
   
  But after a while...i still went back to my floorstanders...i cant get away from the paradigm of a tweeter/mid/bass driver set.
  If u dun need the sub...power to u man!!


----------



## hifuguy

> The nice thing about USB cable transfers is that due to the discrete nature of the signal, all you need is to verify error rate (since the analog conversion is done down the chain inside the DAC). Do you think running the USB cables in loopback and measuring bit error rate would suffice? Or is that not fair game here?
> 
> Say something like this:
> http://www.protechdiagnostics.com/usb-loop-back-plugs.htm#
> ...


 
   
  I don't think the sound quality that we have been debating here about USB cables is the result of data errors. I think the tester gizmos in the links above would give a pass to most any USB cable. I'm the first to admit that the underlying reasons as to why USB cables sound so different is challenging to understand. Audio, in the rarefied context that all of us talk about and love so much, is incredibly fragile. If I understood all of this, I'd patent the intellectual property aspects of it and start a company too.


----------



## hifuguy

> hey hifiguy....
> i had a REL subwoofer before...quite musical when properly matched to my bookshelf speakers...but my neighbours hated it when the dinosours stomped thru my living room.
> 
> But after a while...i still went back to my floorstanders...i cant get away from the paradigm of a tweeter/mid/bass driver set.
> If u dun need the sub...power to u man!!


 
   
  The Rel Subs are very nice.... cool for you. The sub I tried briefly wasn't in that league. You sound happy and that's what this is all about. My room isn't treated accoustically. It's my family room and the chances of my wife going for that idea are a big fat zero. Kind of a bummer, but that's my reality. In addition to the challenge of getting the "right" sub in the "right" place and adjusted just "right," I'm pretty sure my room might be best left 'unexcitted" at the real low (yummy) frequencies. I sometimes think a sin of omission is better than a sin of commission. As you say, "If u dun need the sub"...   Thanks so much for your thoughts!


----------



## Lorspeaker

tot i read somewhere that usb data of 0s and 1s are not really 0s n 1s....
  but a series of valleys( counted as 0s...) ...and peaks (counted as 1s )...
  and below that waveform...there are aload of other signals that got transmittd as sound..luxurious sound or noise otherwise.
   
  much like fuzzy logic in a washing machine...
  4.5 / 4.9kg..5kg....its a full load..
  2.3/ 3 kg...its a half load.
   
  i am no scientist..or electrical engineer..
   
  if i dun get at least a half load on my truck..its a NO GO...tats a  "0
  if i get around 3/4 load..thats a GO...its a "1"


----------



## ultrabike

Quote: 





mikeaj said:


> I don't think you can reduce it to BER (well, bits flipped over the channel, prior to coding / retransmission / whatever it does).  People are always going to make a big deal out of the small stuff.
> 
> If the device is USB bus powered, then surely the cable can be considered part of the power supply in a sense, and it may make some small difference—particularly if the "cable" in question is doing things like including a ferrite bead, rather than just being conductors in a sheath; or if you have a massive source of EMI nearby and you're touting a well-shielded cable.  If the ground, power, or signal lines are not isolated, then some kind of very small effect could couple into the analog parts of the DAC... or even if there is galvanic isolation maybe there could be some effect, and so on.


 
   
  If the device is USB powered then the problem will couple through the interconnects and the cable will matter little as far as that goes. I would make sense to me that a better source and/or DAC would make the difference.
   
  The USB cable can have an affect on the signal due to a ferrite bead, EMI pick up, poor contact, out of spec length and/or gauge. This will translate into a higher noise floor, jitter, and affect the cable transfer function (ferrite bids, cable gauge and length.) All these parameters will affect bit error rate which is a direct function of SNR. FWIW, the test "gizmos" have the following disclaimer about cables:
   
  "While just about any USB cable will work, it is better to select a *quality high speed, shielded, USB cable when testing*. Note that some of the *cheaper USB cables are not shielded and thus are not recommended*. The *cable must be shorter than the 5m allowed in the USB standard*. If a USB connection is required beyond 5m one or more hubs are required to extend a USB connection. *We have noted during our testing that longer cables are more likely to have higher error rates*."
   
  So crappy cable should have crappy BER performance, in their experience.
   
  Quote: 





> Originally Posted by *mikeaj* /img/forum/go_quote.gif
> 
> *Note that "some small difference" doesn't necessarily imply a difference that people will pick up*.
> 
> When the DAC is being clocked by a crystal oscillator, DAC is getting info through I2S or something from the USB receiver (so jitter or other small irregularities on the USB transmission itself are quite isolated from the operation of the DAC), power supply rails are all filtered, some reasonable design standards are applied, it really seems like there shouldn't be much effect from any part of the USB transmission itself, so long as all the data gets there on time.  That's regardless of asynchronous mode or whatever people want to use.  And *if there is some effect from the USB transmission, it seems like the active parts of the system, rather than the cable connecting those elements, should have a much larger impact.*


 
   
  Yup!


----------



## mikeaj

Quote: 





lorspeaker said:


> tot i read somewhere that usb data of 0s and 1s are not really 0s n 1s....
> but a series of valleys( counted as 0s...) ...and peaks (counted as 1s )...
> and below that waveform...there are aload of other signals that got transmittd as sound..luxurious sound or noise otherwise.
> 
> ...


 
   
  For digital communications (just looking at the data transmission, not anything else now), there is some digitally-encoded information that gets sent from a transmitter to a receiver.  To actually send information somewhere in the real world, you need to transmit a (analog) signal, with some kind of predetermined agreement between the transmitter and receiver of what analog signal (symbol) corresponds to what information.  There are lots of different ways to map the digital information to analog signals, with different advantages and disadvantages, and often times there are a lot of intermediate steps and mappings between the original digital information and the symbols that are transmitted, not to mention all kinds of higher-level book-keeping / management / framing aspects to keep things going smoothly.  Something like USB is fairly simple.  It's the difference in voltage between two lines that is used for signalling.
   
  As you say, there are a range of analog values that when received will be interpreted by the receiver as a '0' symbol and another range corresponding to a '1' symbol.  If a voltage corresponding to '1' is sent and the received voltage is so far off it's in the '0' range, then it will be incorrectly interpreted as a '0', resulting in a bit error.
   
  So long as all the information (encoded as those '0' and '1' symbols) gets across, there's no data loss or change in anything.  End of story.  There's no hidden other data that corresponds to the music.  The music data is represented wholly by the digital information that's sent, that gets interpreted as those '1's and '0's.  For some systems, there is built-in redundancy and/or automatic retransmissions if something goes wrong.
   
   
  So people are either implying a difference in bit error rate (probability of '1' sent and '0' being interpreted and vice versa, to simplify it), or something other than the operation of the digital communications link, that's different.  See my previous post about some of the potential "something else" issues—or non-issues, depending on your perspective.
   
   
   
   


ultrabike said:


> The USB cable can have an affect on the signal due to a ferrite bead, EMI pick up, poor contact, out of spec length and/or gauge. This will translate into a higher noise floor, jitter, and affect the cable transfer function (ferrite bids, cable gauge and length.) All these parameters will affect bit error rate which is a direct function of SNR. FWIW, the test "gizmos" have the following disclaimer about cables:


 
   
   
  That's true: those things will affect bit error rate too.  I tend to think of small BER as pretty much 0 (comparing 0 vs. 0 in my head...), since pretty much every system I look at has FEC, so it doesn't matter.  How long do they need to run the testers to get a significant number of errors?  Seems like it'd be a snorefest waiting for errors to accumulate.  




   
  fake edit:
   
  I found something.
   
   
   

   
  10 minutes per test to ensure no errors in 2.996 * 10^12 bits... (USB3 draft)


----------



## ultrabike

Quote: 





mikeaj said:


> 10 minutes per test to ensure no errors in 2.996 * 10^12 bits... (USB3 draft)


 
  Given a decent source and quality DAC, it sounds like a lot of flawless music through standard USB cables 
	

	
	
		
		

		
		
	


	



   
  BTW, by better source and quality DAC, I mean by implication better USB transceivers.


----------



## bigshot

lorspeaker said:


> .i am just sad that the mcbookAir hasnt got a usb3 socket...sobsob.




We already gave you the tip on that. HDMI is your friend.


----------



## bigshot

hifuguy said:


> I don't think the sound quality that we have been debating here about USB cables is the result of data errors.




That's all a cable can do. It can't improve the sound. It either passes the data across without changing it, or it distorts it. Wires don't have magical properties to make music more musical or anything like that.


----------



## bigshot

I have Never understood the need for an external DAC anyway. Perhaps that's because I'm a Mac guy. If the computer comes with excellent audio in and out, and your iPod had the same DAC as in standalone CD players, why string up a chain of Christmas lights just to play a song?


----------



## Lorspeaker

Quote: 





bigshot said:


> We already gave you the tip on that. HDMI is your friend.


 
   
[size=1em] *[size=1.3em]Moshi Mini DP to HDMI adapter[/size]*[/size]        The Moshi Mini DisplayPort to HDMI adapter lets you connect to a display or HDTV that uses an HDMI connector. It supports full HD video display at 1080p (1920 by 1080), as well as HDMI audio pass-through. Compatible with Mac computers with Mini DisplayPort or Thunderbolt ports.

       
  *None [Subtract S$ 54.00]*
  *Moshi Mini DisplayPort to HDMI Adapter (with audio)*

   
  think i will need to add an adaptor if i go hdmi..


----------



## hifuguy

Quote: 





bigshot said:


> That's all a cable can do. It can't improve the sound. It either passes the data across without changing it, or it distorts it. Wires don't have magical properties to make music more musical or anything like that.


 
  Not true. Some USB cables harm the music less... and there you have it. We simply disagree.


----------



## bigshot

Uh... I don't see how we disagree. You just said the same thing I did.


----------



## danne

Quote: 





bigshot said:


> I have Never understood the need for an external DAC anyway. Perhaps that's because I'm a Mac guy. If the computer comes with excellent audio in and out, and your iPod had the same DAC as in standalone CD players, why string up a chain of Christmas lights just to play a song?


 
  Then you really need to head out there to your local dealer and audition some DACs the diffrence is HUGE.
  No computer today comes with excellent audio.


----------



## ultrabike

Quote: 





bigshot said:


> I have Never understood the need for an external DAC anyway. Perhaps that's because I'm a Mac guy. If the computer comes with excellent audio in and out, and your iPod had the same DAC as in standalone CD players, why string up a chain of Christmas lights just to play a song?


 
   
  I have an HP laptop these days with fabulous beats audio 
	

	
	
		
		

		
			





... It's still an upgrade from my 5 year old Dell. Eventually I will bypass their annoying automatic volume gain control buried deep inside MickeySoft Windoze. I have it running Ubuntu via wubi to bypass beats awesomeness.
   
  If you have a desktop with a good soundcard, or if a Mac's laptop audio card gets the job done I guess life is good 
	

	
	
		
		

		
		
	


	




.


----------



## bigshot

Danne, do you have a Mac? Because it isn't like with PCs. My Mac Mini A/V server kicks ass major league. I'd put it up against anything. It's designed to be an audio and video hub from the ground up. Plug and play.

I'm driving a high end screening room and listening room off a little Mac Mini. It's really all you need. HDMI out, straight into my Yamaha amp. Piece of cake. The analogue out sounds just as good.


----------



## ultrabike

Quote: 





bigshot said:


> Do you have a Mac? Because it isn't like with PCs. My Mac Mini A/V server kicks ass major league. I'd put it up against anything. It's designed to be an audio and video hub from the ground up. Plug and play.
> I'm driving a high end screening room and listening room off a little Mac Mini. It's really all you need.


 
   
  Nope. I'm considering an iPad in the near term for somewhat portable (my Sansa Zip cuts it for portable for now.) I currently use a Netgear NeoTV550 to pump bits out of my NAS into my Yamaha  RXV-663 via *monoprice* HDMI cables 
	

	
	
		
		

		
		
	


	




. My little ones get to use it more though... Pixar get's a lot of play time these days. At night got to keep it low, so it's just my laptop and my phones...
   
  Maybe a DAC/amp in the future to improve on my laptop's sound card (though I have Total Bithead which I sometimes use), and some better phones. Leckerton UHA-6 mkII seems well regarded, we'll see...


----------



## nanaholic

Quote: 





bigshot said:


> I have Never understood the need for an external DAC anyway. Perhaps that's because I'm a Mac guy. If the computer comes with excellent audio in and out, and your iPod had the same DAC as in standalone CD players, why string up a chain of Christmas lights just to play a song?


 
   
  I build my own PCs, I want a better sound card and/or external DAC just for the fact that most integrated sound chips on PC motherboards have poor shielding which picks up EM noise that you can actually hear with sensitive IEMs.


----------



## OJNeg

Quote: 





nanaholic said:


> I build my own PCs, I want a better sound card and/or external DAC just for the fact that most integrated sound chips on PC motherboards have poor shielding which picks up EM noise that you can actually hear with sensitive IEMs.


 
   
  I pick up line noise from my onboard soundcard even with full-size headphones. Not the case with my dedicated sound card though.


----------



## drez

Quote: 





dvw said:


> So what you are saying is the DAC receives its clock from the computer. How exactly does it work? USB2.0 runs 488MHz and the DAC runs 44KHz. What if I have a USB1 or USB3, won't that really screw up the system?
> 
> Let's assume if indeed you get your clock from the computer. Let's say my music is recorded at 43KHz (there will be tolerance and I am exaggerating the difference) and you are running 44KHz. Won't that cause buffer under run?
> 
> People are confused by synchronous transmission and synchronous timing. Synchronous transmission is synchronous to a transmit schedule which gurantees bandwidth and latency that's important in real time communication. Synchronous timing refers to clock synchronization which is necessary to recover data.


 
   
  Thanks for explaining this - so with synchronous adaptive transmission the DAC uses an [adaptive] control circuit to clock the PCM data output based on the average transfer rate, but the computer is in charge of clocking the data transmission to the USB device?
   
  I think I did mix up synchronous timing with synchronous transmission.


----------



## drez

Quote: 





bigshot said:


> "Real World" is what human beings can actually hear.
> Welcome to Sound Science. Sorry about your misconceptions.


 
   
  So there is no reality outside of what can be proven to others?  Is something real if it has not yet been proven?


----------



## TickleMeElmo

Quote: 





drez said:


> So there is no reality outside of what can be proven to others?  Is something real if it has not yet been proven?


 
   
  If something runs counter to accepted and already proven theories it is the responsibility of the former to prove the existence and/or validity of the claim. Just as lack of proof doesn't necessarily imply falsehood, lack of proof to the contrary is not equivalent to truism.
   
  If A is true and any such B contradicts A, proving B is true would mean A is untrue. Inductively if B cannot be proved true we can say A is true in the general case. If no arbitrary B can be produced we can say that A is true and B is false.
   
  To me (correct me if I am wrong), to prove there is a difference in sound one would have to:
   
  A) Show quantitatively that an average (working) USB cable is unable to transport data as well as a high end cable. This can be done through monitoring packets or otherwise. Since it is a digital signal it should be bit perfect, this is quite easily to verify unlike analog signal that can depend on the sensitivity of the testing instruments. If the data is verified as having no errors it is unequivocal proof that cables make no difference.
   
  B) ABX testing with statistically valid sample sizes. Since with any statistical test even as n goes to infinity one cannot state with true certainty ABX testing is only useful if case A) is inconclusive. It A proves there is no data degradation or otherwise but ABX testing shows statistically valid differences the analytic solution will always take precedence over statistical and numerical methods. 
   
  This argument cannot be necessarily extended to analog signal because then you are limited by the accuracy and precision of measuring equipment.


----------



## bigshot

nanaholic said:


> I build my own PCs, I want a better sound card and/or external DAC just for the fact that most integrated sound chips on PC motherboards have poor shielding which picks up EM noise that you can actually hear with sensitive IEMs.




It's a PC thing I guess. I've never had a Mac that had EM interference. Even the very first AV Mac with audio in and out I had 15 years ago. Mac sound has always been as good as you possibly need.


----------



## hifuguy

Sighhh... A good USB cable really does sound better.... way better. This phenomenon isn't caused by bit errors. It goes beyond our expertise here to talk about it with any degree of authority. If the issue were simple bit errors, the difference between an average USB cable and a high-end USB cable would not be manifested as a loss in sound-staging, frequency response, dynamics, pace, (add your own here) and the subtle nuances that make music so enjoyable to us. If a most-significant bit error occurred, then such errors would result in a click/pop artifact. That not what happens between run-of-the-mill and high-end USB cables. If bit errors were responsible, the musical integrity would come and go, it would be intermittent. That doesn't happen either.
   
  Please move past the theory and try it on a nice system... preferably not a Yamaha receiver. Go visit a good dealer (or perhaps find a nice company with a  trial period), bring your nice $20 Belkin USB cable and ask them to swap it out with a really good USB cable. Start to finish, it should take less than 15 minutes (well maybe an hour, because like all of us who have done this, you'll go back and forth 3 times in disbelief)..If you have invested in computer-based music, and you don't do this, then you're leaving musical performance that you paid for on the table. That's sad... and that's why I took the time to share my experiences with all of you. Don't let the lack of explainable theory keep you stuck in the land of mid-fi. Once you hear the difference, you can enjoy your music more than ever, and then still go back and try to understand it... but good luck... you'll need it. If any of you really do take the challenge,  then report back what happens. That would make me happy. Better yet, PM me as I don't expect to participate in this discussion any further..Bye guys. Happy Listening... I tried my best...


----------



## Griploc

Im running an intel mac mid 2010 with an apogee symphony io dac. The truth is the sound quality changes significantly when u have good converters and good clocking recording digital.


----------



## bigshot

hifuguy said:


> If a most-significant bit error occurred, then such errors would result in a click/pop artifact.




That isn't necessarily true. Jitter, if it does reach audible levels (which it rarely does), operates in a time frame measured in picoseconds. That is a sliver of time that is so minute, you wouldn't hear it as a pop at all. It would sound more like distortion.

But I wouldn't know for sure, because I've never heard jitter, because it pretty much doesn't exist at audible levels in consumer stereo equipment.

It really pays to be a little bit skeptical and to chase down the truth yourself instead of taking the word of equipment manufacturers. If you really know what is going on, at least at a basic level, it really helps you determine what can make a big difference and what can't. When you hear someone say that improvements aren't measurable, or talk about vague improvements in things like soundstage or imaging, you can be pretty sure they're building their reputation on placebo effects. Madison Avenue plays on this sort of thing all the time. It's more common than most people think. All you have to do to counteract it is engage in a little healthy skepticism.

As for conducting a test at a retailer... Let me tell you a little story about when I was shopping for speakers...

I knew I wanted good speakers, so I went to a pretty high end shop in West LA. I was young, so the salesman gave me a look of disdain, but deigned to demo some speakers for me. He insisted that he would run the switcher. I would just point at what I wanted to hear. I was listening and comparing, and I happened to be looking at the salesman as he switched, and his hand quickly turned a dial when he thought I wasn't looking. I walked over to him and looked at the dial. It was the bass control. He had been boosting and cutting the bass as he switched to make me think one set of speakers were better than another.

I called him on it and told him we'd be there all day trying to figure out which sounded the best if he insisted on changing the settings. He got huffy. Didn't say a word. Just walked away and waited on another custmer. I caught a guy doing the same trick at Circuit City once.

Retailers are the worst place to try to run a controlled comparison. They will flat out try to trick you. Even the good ones. All it takes is a salesman with a low commission total that week.


----------



## bigshot

griploc said:


> Im running an intel mac mid 2010 with an apogee symphony io dac. The truth is the sound quality changes significantly when u have good converters and good clocking recording digital.




I'm talking only about playback. Recording requires a whole different level of sound quality. It's a different kettle of fish.


----------



## danne

Quote: 





bigshot said:


> Danne, do you have a Mac? Because it isn't like with PCs. My Mac Mini A/V server kicks ass major league. I'd put it up against anything. It's designed to be an audio and video hub from the ground up. Plug and play.
> I'm driving a high end screening room and listening room off a little Mac Mini. It's really all you need. HDMI out, straight into my Yamaha amp. Piece of cake. The analogue out sounds just as good.


 
   
  I do have both a PC, Mac mini, macbook air, ipad etc and there is just miles apart in audio quality when using an external DAC with all of them.
  However if you are happy with the sound, there is no need to look further, it will save you alot of money for other stuff.


----------



## ultrabike

Quote: 





hifuguy said:


> Sighhh... A good USB cable really does sound better.... way better. This phenomenon isn't caused by bit errors. *It goes beyond our expertise here to talk about it with any degree of authority*. If the issue were simple bit errors, the difference between an average USB cable and a high-end USB cable would not be manifested as a loss in sound-staging, frequency response, dynamics, pace, (add your own here) and the subtle nuances that make music so enjoyable to us. If a most-significant bit error occurred, then such errors would result in a click/pop artifact. That not what happens between run-of-the-mill and high-end USB cables. If bit errors were responsible, the musical integrity would come and go, it would be intermittent. That doesn't happen either.
> 
> Please move past the theory and try it on a nice system... preferably not a Yamaha receiver. Go visit a good dealer (or perhaps find a nice company with a  trial period), bring your nice $20 Belkin USB cable and ask them to swap it out with a really good USB cable. Start to finish, it should take less than 15 minutes (well maybe an hour, because like all of us who have done this, you'll go back and forth 3 times in disbelief)..If you have invested in computer-based music, and you don't do this, then you're leaving musical performance that you paid for on the table. That's sad... and that's why I took the time to share my experiences with all of you. Don't let the lack of explainable theory keep you stuck in the land of mid-fi. Once you hear the difference, you can enjoy your music more than ever, and then still go back and try to understand it... but good luck... you'll need it. If any of you really do take the challenge,  then report back what happens. That would make me happy. Better yet, PM me as *I don't expect to participate in this discussion any further..Bye guys. Happy Listening... I tried my best...*


 
   
  Chill out dude. If you were/are in disbelief, it should be understandable that others would be as well. I personally found your audio rig really cool... I just haven't bought into the USB cable awesomeness deal.
   
  You've got to understand where I'm coming from. I used monoprice USB (Hard Drive to Media Player) and HDMI (Media Player to Receiver) cables and bro I was floored when experiencing my HD movies video and audio. 1080P video was simply flawless, and DTS-HD audio was mosquito fart revealing... What can I say? Maybe I'll give Uber-USB cables a try...
   
  Also, If I did hear a dramatic improvement, I would make an attempt to figure out why that is. Saying that no _degree of authority_ or _expertise _will ever be able to explain what's going on sounds a bit defeatist to me. To start with, how did the USB cable manufacturer found out the secret formula for this metallic uber-conductive technological wonder? What's the deal with "ultra pure DCT-UP-OCC-Ag" and "CryoFreeze process"? Shielding makes sense, but what about damping? Damping what? I don't see anything wrong with trying to figure out what's going on...


----------



## liamstrain

hifuguy said:


> A good USB cable really does sound better.... way better. This phenomenon isn't caused by bit errors. It goes beyond our expertise here to talk about it with any degree of authority. If the issue were simple bit errors, the difference between an average USB cable and a high-end USB cable would not be manifested as a loss in sound-staging, frequency response, dynamics, pace, (add your own here) and the subtle nuances that make music so enjoyable to us.


 
   
   
  please explain how the frequency response can change with a USB data stream. A 0 or 1 does not make a note slightly higher or lower or clearer if it is transmitted better, it is still a 0 or a 1 when it hits the A/D conversion. Likewise dynamics or pace, etc. 
   
  Great if you want to believe that your cable makes a difference. Maybe it actually does, but since you have not done any blind testing, or measurements, we cannot say for sure - especially in the light of there being no current reason or theory supporting that it should or even could make a such a difference.
   
  All we are asking for is objective evidence to back up your claims, or even a good theory that explains why you hear what you say you hear. Then we can talk. 
   
  For the record, I have tried many "good" USB cables, and heard no difference under level matched, blind switching listening tests.


----------



## mikeaj

Even supposing there were differences to detect, usually the big changes are between different low-end gear or maybe between low-end and midrange, for a number of reasons.  It's usually not going to be the expensive product that's a revelation or a tier way above.
   
  The exception may be when there's a new process or technology that delivers something never seen before, and the new product works by a different set of principles than the old stuff.  Then that's more a matter of different technology than low- vs. high-end.


----------



## paradoxper

Quote: 





mikeaj said:


> Even supposing there were differences to detect, usually the big changes are between different low-end gear or maybe between low-end and midrange, for a number of reasons.  It's usually not going to be the expensive product that's a revelation or a tier way above.
> 
> The exception may be when there's a new process or technology that delivers something never seen before, and the new product works by a different set of principles than the old stuff.  Then that's more a matter of different technology than low- vs. high-end.


 
  Are we talking actual objective new technology or could buzzword marketing and or placebo be included?


----------



## liamstrain

I hope, since we are in Sound Science, actual objective new technology.


----------



## mikeaj

I was thinking about real changes, like along the lines of Laserdisc -> DVD, but maybe it's applicable elsewhere.


----------



## paradoxper

Quote: 





liamstrain said:


> I hope, since we are in Sound Science, actual objective new technology.


 
  Well, from a certain other "SS" thread, SS = Objective means moot.


----------



## liamstrain

Quote: 





mikeaj said:


> I was thinking about real changes, like along the lines of Laserdisc -> DVD, but maybe it's applicable elsewhere.


 
  I think definitely - I would not at all be surprised, for instance in improved D/A conversion chips or music encoding, or even better transmission protocols (async timing) etc. Things that actually can affect what happens with how digital data is encoded and decoded. THAT makes sense. But not the wire they are transmitted on.


----------



## ultrabike

I honestly don't think we have all the answers, and for me it's easier to understand that different topology amps/DACs would sound different, specially when coupled with different types of cans.  For example, my Total BitHead, my Sansa Zip, my Creative Zen, and my laptop all sound different (my laptop beats audio is hands down *worse* btw). Harder to swallow that there are life changing differences among two 28 AWG cables that pass error corrected 1's and 0's... But who knows...
   
  Maybe the cable acts as an ideal low pass filter that removes out of band noise, and prevents it from aliasing into the DAC (and affecting the conversion stages inside the DAC) before 1's and 0's even make it to the USB receiver interconnects. Aliens did it, or you can't figure it out by definition is IMO not an acceptable answer though.


----------



## bigshot

danne said:


> I do have both a PC, Mac mini, macbook air, ipad etc and there is just miles apart in audio quality when using an external DAC with all of them.




How do you connect an external DAC to an iPad?

I'm basing my comments on a line level matched direct A/B comparison of my Macs' and iPods' audio out to grood standalone CD and SACD players. The sound with uncompressed audio is identical. If there is a difference I'm not hearing, it really can't be miles apart. I would have heard it.

My Mini is now running into my AV amp so I can decode 5:1, but I couldn't tell any difference because of that, except that 5:1 sound is a huge improvement over two channel.

It seems to me, if a computer or portable device sounds exactly like a $1000 standalone player, there isn't much room for improvement over that.


----------



## bigshot

ultrabike said:


> If I did hear a dramatic improvement, I would make an attempt to figure out why that is.




That's a very important point.

I actually *have* made dramatic improvements in the quality of my sound in the past. But that was never from just swapping in some piece of equipment randomly, just because people say it's good. Whenever I was able to make a nice leap forwards, it's always because I... 1) Identified a specific shortcoming in my rig, 2) Researched how to specifically address the problem, and 3) verified after I had made a change that the improvement I was intending to make had happened.

Getting good sound is a lot like parallel parking a car. You have to go back and forth, makng more and more precise adjustments until you reach your goal. You don't get there by just turning the wheel any old which way and hitting the gas.


----------



## bigshot

mikeaj said:


> Even supposing there were differences to detect, usually the big changes are between different low-end gear or maybe between low-end and midrange, for a number of reasons.  It's usually not going to be the expensive product that's a revelation or a tier way above.




With CD players in particular, I've found that low and midrange equipment is of remarkably high quality, and are remarkably consistent. A high end CD player is more likely to be wonky because of a boutique manufacturer coloring the response to achieve a "house sound signature".

Solid state amps are similar, but more expensive amps either have more power or distortion and noise specs that extend beyond the inaudible levels that are common with midrange equipment. Again, high end tube amps are the most likely to perform out of spec, but they're designed to do that.


----------



## bigshot

mikeaj said:


> I was thinking about real changes, like along the lines of Laserdisc -> DVD, but maybe it's applicable elsewhere.




My high end laserdisc player cost ten times what my cheapo bluray player cost. You're right, the low end and midrange categries don't really apply here.


----------



## danne

Quote: 





bigshot said:


> How do you connect an external DAC to an iPad?
> I'm basing my comments on a line level matched direct A/B comparison of my Macs' and iPods' audio out to grood standalone CD and SACD players. The sound with uncompressed audio is identical. If there is a difference I'm not hearing, it really can't be miles apart. I would have heard it.
> My Mini is now running into my AV amp so I can decode 5:1, but I couldn't tell any difference because of that, except that 5:1 sound is a huge improvement over two channel.
> It seems to me, if a computer or portable device sounds exactly like a $1000 standalone player, there isn't much room for improvement over that.


 
   
  The ipad can be connected with the "camera connection kit" that makes you able to get USB out from the ipad.
  What speakers are you running with your reciver btw?


----------



## bigshot

ultrabike said:


> I honestly don't think we have all the answers, and for me it's easier to understand that different topology amps/DACs would sound different, specially when coupled with different types of cans.  For example, my Total BitHead, my Sansa Zip, my Creative Zen, and my laptop all sound different (my laptop beats audio is hands down *worse* btw).




It's hard for me to wrap my head around this, but I'm realizing that in the PC world, there is a lot of jerry rigged solutions that produce a range of results, from craptastic to good. I've always had Apple products and they've always performed exactly the same... perfect out of the box. I've found the same to be true of most CD players and receivers or amps. All the ones i've had just plain worked until they died.


----------



## bigshot

danne said:


> What speakers are you running with your reciver btw?




A combination of JBL towers and studio monitors and a Sunfire HRS 12 subwoofer. The rears are Klipsch bookshelves.


----------



## paradoxper

Quote: 





bigshot said:


> It's hard for me to wrap my head around this, but I'm realizing that in the PC world, there is a lot of jerry rigged solutions that produce a range of results, from craptastic to good. I've always had Apple products and they've always performed exactly the same... perfect out of the box. I've found the same to be true of most CD players and receivers or amps. All the ones i've had just plain worked until they died.


 
  Big, do you use any parametric eq'ing or hardware? And what music player are you using on OS X?


----------



## bigshot

Oh yeah! I've been finessing the EQ for the past four months! EQ makes ALL the difference. It's a six band parametric. I need a graphic too for little bumps but I can't afford it right now. My Rane analogue one won't jive with the 5:1.

I use iTunes as my music server. Video is played back using Plex. About 35 TB of online storage on four Drobos. Sony bluray player. Yamaha AV receiver.

My system is a solid 2:1 with smaller speakers to fill in 5:1 for movies. I have an Epson 8500UB 1080p projector and a ten foot screen. The room doubles as a listening room and screening room.


----------



## paradoxper

Quote: 





bigshot said:


> Oh yeah! I've been finessing the EQ for the past four months! EQ makes ALL the difference. It's a six band parametric. I need a graphic too for little bumps but I can't afford it right now. My Rane analogue one won't jive with the 5:1.
> I use iTunes as my music server. Video is played back using Plex. About 35 TB of online storage on four Drobos. Sony bluray player. Yamaha AV receiver.
> My system is a solid 2:1 with smaller speakers to fill in 5:1 for movies. I have an Epson 8500UB 1080p projector and a ten foot screen. The room doubles as a listening room and screening room.


 
  And where do you place your eq since there aren't really rules to placement?


----------



## bigshot

I started by using automatic EQ. Then I've been adjusting by ear using a variety of classical recordings. A sound engineer buddy is coming by soon with a signal generator to help me fine tune it to flat.


----------



## paradoxper

Quote: 





bigshot said:


> I started by using automatic EQ. Then I've been adjusting by ear using a variety of classical recordings. A sound engineer buddy is coming by soon with a signal generator to help me fine tune it to flat.


 
  What is automatic EQ? Presets? Flattening out a EQ for playback excessive much? or is that for producing/mixing.


----------



## mikeaj

Quote: 





liamstrain said:


> I think definitely - I would not at all be surprised, for instance in improved D/A conversion chips or music encoding, or even better transmission protocols (async timing) etc. Things that actually can affect what happens with how digital data is encoded and decoded. THAT makes sense. But not the wire they are transmitted on.


 
   
  Right.  The things you mention make a lot more sense for making an appreciable difference.  But there's not even much evidence to show that even these kinds of changes add up to any type of practical difference in home audio playback, so long as the baseline you're comparing to is reasonably okay (which can be done pretty cheap these days).
   
   
  One thing that bugs me* is how people seem attracted to the little tweaks, sweating the tiny things that could possibly conceivably make a change, things that—if they truly are valid—are so small that nobody's yet been able to validate them in controlled listening tests or bench measurements.  To me, if you want to obsess at details that small, I think you should be taking care of business in all other aspects that everybody knows actually makes a difference, e.g. room treatment / correction / EQ.  Or purchasing multiple copies of your favorite headphones so you can find drivers that are better matched or sound better.  I mean, the difference between different headphone samples of the same model, or different headphone positioning of the same headphones on the same person's head, seem to be an order of magnitude or two above the differences in some amplifiers, not to mention some cables, not to mention _digital_ cables.  IMHO, something doesn't add up.
   
  *not that I'm actually bothered.  People are free to do as they please.  I mean that it seems counterproductive, or that I think that priorities may be misplaced.  It's a curiosity.  And I think it has to do with some tweaks seeming _cooler_ than others and not particularly with what actions would be rationally motivated by some kind of price-to-performance analysis.
   
  I want to see a high-end headphone placement robot.  It puts headphones on the exact same spot on your head, every time!


----------



## bigshot

paradoxper said:


> What is automatic EQ? Presets? Flattening out a EQ for playback excessive much? or is that for producing/mixing.




The equalizer has an automatic adjustment with a microphone. It didn't work very well. But it gave a good jumping off place. It identified an issue at the crossover point between the full range mains and the subwoofer. The volume balance between the six channels was all messed up though, so I had to do a lot of adjusting by ear to get the channels to couple. Once I got that working, it knocked the response a little off, so I had to adjust that... Which knocked the coupling off again, and so on. Lots of parallel parking, but I'm close now.

I listen to a lot of classical music, so flat response is my goal. I am looking to get to a totally balanced place. No frequencies boosted, none attenuated.


----------



## liamstrain

Don't forget your room treatments - that was the biggest barrier I had in getting anywhere near a flat response in my mixing room.


----------



## bigshot

I'm limited in that because this is a living space, not a work space. But luckily, the room acoustics are quite good and there aren't any glaring problems like glass doors or low angled ceilings. I've taken care with the placement of the speakers and layout of the furniture. The rest is up to the EQ.

http://animationresources.org/pics/clclubhouse2.jpg
http://animationresources.org/pics/clclubhouse.jpg


----------



## liamstrain

Nice! Consider me jealous. My home space is much more limited (darn city condo's)


----------



## bigshot

I lived for 29 years in an apartment with my nice big speakers. It helps to just not care about the neighbors!


----------



## liamstrain

I'm building some new full range back loaded horns... but I had to get clearance from the wife first.


----------



## TickleMeElmo

Quote: 





hifuguy said:


> Sighhh... A good USB cable really does sound better.... way better. This phenomenon isn't caused by bit errors. It goes beyond our expertise here to talk about it with any degree of authority. If the issue were simple bit errors, the difference between an average USB cable and a high-end USB cable would not be manifested as a loss in sound-staging, frequency response, dynamics, pace, (add your own here) and the subtle nuances that make music so enjoyable to us. If a most-significant bit error occurred, then such errors would result in a click/pop artifact. That not what happens between run-of-the-mill and high-end USB cables. If bit errors were responsible, the musical integrity would come and go, it would be intermittent. That doesn't happen either.
> 
> Please move past the theory and try it on a nice system... preferably not a Yamaha receiver. Go visit a good dealer (or perhaps find a nice company with a  trial period), bring your nice $20 Belkin USB cable and ask them to swap it out with a really good USB cable. Start to finish, it should take less than 15 minutes (well maybe an hour, because like all of us who have done this, you'll go back and forth 3 times in disbelief)..If you have invested in computer-based music, and you don't do this, then you're leaving musical performance that you paid for on the table. That's sad... and that's why I took the time to share my experiences with all of you. Don't let the lack of explainable theory keep you stuck in the land of mid-fi. Once you hear the difference, you can enjoy your music more than ever, and then still go back and try to understand it... but good luck... you'll need it. If any of you really do take the challenge,  then report back what happens. That would make me happy. Better yet, PM me as I don't expect to participate in this discussion any further..Bye guys. Happy Listening... I tried my best...


 
   
  Who are you to say it is beyond our expertise to talk about? If you can't understand basic protocols of computer science, it doesn't mean that nobody else can. Please don't bring everyone to your level if you don't understand something by trying to obfuscate and mystify it.
   
  Your experiences are invalid. It's like going to a chemotherapy ward and telling the patients there they should stop taking treatment because you know of this really good homeopath down the road that can heal them for next to no money.


----------



## dleblanc343

Here's a facebook post I made just now:
  
 "Nerdiest thing in the world. Testing the difference in sound of usb cables through a semi-high end audio system. With digital cables, the signal either passes to the next component or it doesn't; there's no in between or "better" transmission. It's one or the other, therefore it should sound the same.

 BUT IT DOESN'T"   
  I am being serious, no intent to troll or stir up trouble/ be a sower of discord. I can't really accept it either, I was 95% expecting no difference and 5% expecting the slightest lifting of a veil across the audio spectrum... but what did I get? More than that. Well, an hour of A/B'ing between 4 songs and each time I could tell the same differences. I have great ears, but I still believe anyone would be able to hear it.
   
  My mind is not playing tricks, I HEAR IT. I am mad, because the audioquest cable is inferior compared to the tellerium cable I loaned from a dealer. I can't believe the difference because 1. it's a digital cable and 2. it's being processed by the dac and then the amp; after the dac, it should sound the same.
   
  I will elaborate on each track I tried and what exactly sounded different later on. I'm startled by my testing and don't feel like typing now. (I already feel it's a waste of time to write about this but I will do it).
   
  Two things I need to consider though. The audioquest carbon cable uses copper, the tellerium is pure silver. Also, the tellerium is about 1 meter, whereas the audioquest is 1.5 meters.
   
  I also used SoX resampler to upsample to 192 even though CD rips are at 44.1 bitrate. All songs are in wav format. I noticed songs clipping more often, while being upsampled, when using the audioquest.
   
  I would actually consider paying the 350$ for the tellerium if I can sell the audioquest for what it cost me. And my coworkers and I at the Hi-Fi boutique were laughing about the ludicrous price of this cable just earlier today.
   
  I don't want to create any hype, but I think I'm a believer now 
	

	
	
		
		

		
			




   
  Daniel
   
  (more to come)


----------



## paradoxper

Quote: 





dleblanc343 said:


> Here's a facebook post I made just now:
> 
> "Nerdiest thing in the world. Testing the difference in sound of usb cables through a semi-high end audio system. With digital cables, the signal either passes to the next component or it doesn't; there's no in between or "better" transmission. It's one or the other, therefore it should sound the same.
> 
> ...


 
  Not being rude, mean, or trolling you. I actually sit in a neutral camp.
   
  Why if no one has ever successfully DBT cables do you find your ears to be the exception, if not for placebo?


----------



## dleblanc343

It's not placebo because there is one bird cry in a song I can _literally not _hear with one cable and barely hear at all with the other.
   
  I can't explain this scientifically, but I can hear it!
  
  And this is after inter-changing cables at least 12 times


----------



## bigshot

The fact that it took you an hour of back and forth A/Bing tells me that the difference is likely very small, if a difference exists at all. Once you've line level matched and set up the switcher, the actual comparison shouldn't take a lot of time.


----------



## bigshot

dleblanc343 said:


> It's not placebo because there is one bird cry in a song I can _literally not_ hear with one cable and barely hear at all with the other.




Did you set up a preamp on each and line level match? I bet that's your problem here.

If you didn't have a switcher to directly compare, it's no good. Auditory memory for similar sounds won't hold up more than a second or two.


----------



## Griploc

playing any music through my apogee symphony io is definitely a boost in quality when it comes to sound big shot. if you are curious to how my room is set up i am using mackie hr 824 mk2's. a well acoustically treated environment, mapleshade audio mounting system for my apogee symphony io  and mapleshade audio isoblocks under my imac. i have much more gear, just giving you an idea of the signal chain from computer to dac to nearfield monitors. mogami cabling throughout system as well


----------



## paradoxper

Quote: 





bigshot said:


> Did you set up a preamp on each and line level match? I bet that's your problem here.
> If you didn't have a switcher to directly compare, it's no good. Auditory memory for similar sounds won't hold up more than a second or two.


 
  x2 ^ I don't mean to belittle your finding or anything. It's almost impossible to do a legitimate A/B switch.


----------



## Citan

Quote: 





bigshot said:


> Did you set up a preamp on each and *line level match*? I bet that's your problem here.
> If you didn't have a switcher to directly compare, it's no good. Auditory memory for similar sounds won't hold up more than a second or two.


 
  Winner!


----------



## bigshot

griploc said:


> playing any music through my apogee symphony io is definitely a boost in quality when it comes to sound big shot.




I've done production sound recording and editing, and I've supervised sound mixes. I had a 24 bit ProTools workstation on my desk at work. I did a lot of testing, because I was the recording and post production supervisor and was responsible for every single track.

What I found was that for recording, ProTools kicked ass. I could take an off mike vocal or a soft guitar lick and boost it as far as I wanted and there would be no noise. But once a mix was done and the track was bounced down to redbook, I could play it on ProTools or on a $150 Yamaha CD player and it sounded the same. The improved quality of the equipment only applied to raising the volume of quiet stuff. At normal listening volume it was identical.

Try a direct A/B line level matched comparison yourself. With a mixing board, it's easy to do. Yu'll find out what I'm talking about.


----------



## drez

Quote: 





ticklemeelmo said:


> If something runs counter to accepted and already proven theories it is the responsibility of the former to prove the existence and/or validity of the claim. Just as lack of proof doesn't necessarily imply falsehood, lack of proof to the contrary is not equivalent to truism.
> 
> If A is true and any such B contradicts A, proving B is true would mean A is untrue. Inductively if B cannot be proved true we can say A is true in the general case. If no arbitrary B can be produced we can say that A is true and B is false.
> 
> ...


 
   
  My point was not to equate evidence, proof and reality but rather the opposite - to bring into focus the tacit belief that in order for something to be real it must first have evidence or proof withing a commonly acknowledged theoretical framework - in this case science.  My point is that there should be distinction between what is considered real and what is considered proven or evidenced by science, otherwise one ends up in a state of hopeless nihilism unable to operate or make progress without the assurance of veritable evidence or proof.  In my previous post I took this philosophy to an extreme case to show that we necessarily consider things which we do not have direct evidence of to be real usually if they agree with our own experiences or understanding of what is possible or likely - but in effect these are best-fit extrapolations reliant on faith in our own experience and understanding of the natural world.
   
  Regarding what you are proposing to be necessary to provide evidence of the influence of USB cables of sound quality for:
   
  A)  The USB specification provides the requirement of 90 Ohms +/- 15% between the digital conductors in order to minimise the signal reflectoins due to impedance of the USB sender and receiver chips.  This impedance is a product of capacitance and inductance in the cable.  One can achieve impedance withing this tolerance with a range of consuctor sizes, shielding arrangements etc but most standard USB cables use a 28 AWG copper conductor twisted or parralel pair with foil shielding and braided tinned copper shield.  Many of the aftermarket cables use  larger gauge for the digital pair or +5V and Gnd conductors in order to minimise resistive losses.  Different shielding and damping arrangements can reduce RF and EM interference as well as crosstalk and microphonics between the wires.  The aim of all this is to transmit the cleanest square waveform possible, however one cannot reduce characteristic impedance past the 90 Ohms +/- 15% otherwise you might increase signal reflections, therefore at most you can possibly reduce resistive loss and noise/interference making the square wave harder to read.  Possibly one could tune the relationship between capacitance and inductance to reduce phase distortion also.  One manufacturer showed a square wave pattern from their cable as part of marketing but in general most manufacturers don't bother with emprirical measurements and rely instead on marketing and reputation/reviews.  The only possibility for USB cable to make an influence is by affecting jitter (resulting from uncertainty in reading the square waveform) and noise of the USB signal.  There is however one sure-fire way to reduce all of these losses which is to use a shorter cable - and unsurprisingly the more expensive USB cables tend to come in shorter lengths than the cheaper models - is this a coincidence?  IMO probably not.
   
  B)  ABX testing - if USB cables to perform significantly differently then yes ABX testing might be able to show a difference.  Problem is that in most ABX tests people have not been able to discern very small differences in sound quality - the one possible exception being the blind tests that ESS conducted when developing the SABRE DAC.  IMO blind testing is very difficult - even for very obvious differences the test can be confusing.  On the other hand cognitive biases make sighted testing problematic.
   
  My opinion is that people do hear differences, but unfortunately it is difficult to tell good from bad.  IME jitter does not always cause a harsher or more grainy sound - in fact it can sound euphonic in my experience.  Because of this it is difficult to tell which audio cues people are responding to.  On the other hand - eye diagrams and distortion plots may not tell you whether the resulting sound will be to your taste.  ABX testing might be an answer if it were less prone to produce null results IMO.


----------



## Griploc

i dont think i agree with your statement. i am also a protools user and i notice improved sound quality on a pro tools session rather than being bounced down to iTunes or downs-ampled from 24 to a 16 bit on a cd to a cd player and a/bing it with my apogee symphony io through my imac or even through my earlier apogee ensemble. huge differences. i am sorry but i do not agree.


----------



## danne

Quote: 





bigshot said:


> I've done production sound recording and editing, and I've supervised sound mixes. I had a 24 bit ProTools workstation on my desk at work. I did a lot of testing, because I was the recording and post production supervisor and was responsible for every single track.
> What I found was that for recording, ProTools kicked ass. I could take an off mike vocal or a soft guitar lick and boost it as far as I wanted and there would be no noise. But once a mix was done and the track was bounced down to redbook, I could play it on ProTools or on a $150 Yamaha CD player and it sounded the same. The improved quality of the equipment only applied to raising the volume of quiet stuff. At normal listening volume it was identical.
> Try a direct A/B line level matched comparison yourself. With a mixing board, it's easy to do. Yu'll find out what I'm talking about.


 
   
  I really do think you should source out your local dealer and ask them to demo some sources for you, couse unlike USB cables, DAC's and CDplayers are well known for making a big diffrence in sound (more or less anyone could tell you this).


----------



## Griploc

agreed danne


----------



## Griploc

as for the usb not making a difference i will be doing a dbt with multiple usb's very soon and will give my upmost honest opinion on the subject as well as my findings on if there is truly any change in sound quality. I really do hope there is because the usb i ordered costs around 350 dollars and itf it doesnt make any changes to my sound quality set up i will be sending it back for an upgraded ac cable.


----------



## Lorspeaker

Quote: 





dleblanc343 said:


> Here's a facebook post I made just now:
> 
> "Nerdiest thing in the world. Testing the difference in sound of usb cables through a semi-high end audio system. With digital cables, the signal either passes to the next component or it doesn't; there's no in between or "better" transmission. It's one or the other, therefore it should sound the same.
> 
> ...


 
   
  bro...is this the cable u bought??   and it killed the audioquest...kool. u must be in sonic shangrila 
   
  if u have money to spare, can u get a wireworld usb too...and give it a go..
   
  ============
   
  hifiguy....cheers..u are the man !


----------



## ultrabike

Quote: 





griploc said:


> as for the usb not making a difference i will be doing a dbt with multiple usb's very soon and will give my upmost honest opinion on the subject as well as my findings on if there is truly any change in sound quality. I really do hope there is because the usb i ordered costs around 350 dollars and *itf it doesnt make any changes to my sound quality set up i will be sending it back* for an upgraded ac cable.


 
   
  Hope they are not charging 20% re-stocking fee. But don't worry mang,  for < $350 you could still get:
   
http://www.amazon.com/Behringer-FBQ2496-Suppressor-Parametric-Equalizer/dp/B000KIPT26/ref=sr_1_1?s=musical-instruments&ie=UTF8&qid=1345185896&sr=1-1&keywords=FBQ-2496
   
http://www.leckertonaudio.com/products/uha-6s-mkii/
   
http://www.amazon.com/Marantz-CD5004-CD-Player/dp/B003R7KMTW/ref=sr_1_12?ie=UTF8&qid=1345182430&sr=8-12&keywords=marantz
   
http://www.walmart.com/ip/Apple-iPod-touch-8GB-with-FaceTime-Camera-and-Retina-Display/15075124?ci_src=14110944&ci_sku=15075124&sourceid=1500000000000003142050&veh=dat
   
http://www.amazon.com/Yamaha-R-S500BL-Natural-Stereo-Receiver/dp/B0044779GI/ref=sr_1_10?s=electronics&ie=UTF8&qid=1345182625&sr=1-10&keywords=yamaha+receiver
   
  and of course... usb cables that dramatically improve sound.


----------



## paradoxper

Didn't really mean to make the guy feel ganged up on.


----------



## bigshot

griploc said:


> i dont think i agree with your statement. i am also a protools user and i notice improved sound quality on a pro tools session rather than being bounced down to iTunes or downs-ampled from 24 to a 16 bit on a cd to a cd player and a/bing it with my apogee symphony io through my imac or even through my earlier apogee ensemble. huge differences. i am sorry but i do not agree.




So you've done an A/B comparison between a 24 bit ProTools session and a redbook CD played in a CD player? You didn't mention that before.


----------



## bigshot

danne said:


> I really do think you should source out your local dealer and ask them to demo some sources for you, couse unlike USB cables, DAC's and CDplayers are well known for making a big diffrence in sound (more or less anyone could tell you this).




All CD players that are operating to specs sound pretty much the same. I've done the comparisons myself with CD players, SACD players and iPods. Put the same exact audio file in them, line up the levels and you'll have a great deal of trouble ever telling them apart without peeking.

Not everyone could tell you that, but not everyone goes to the trouble to test their gear like I do.


----------



## Griploc

i dont have one. but i think a 24 bit audio wav file will sound better than a 16 bit wav file. my DAC converters verses my imac converters will always end up with the DAC winning. it cant compete with the symphony io sound quality alone. i pesonally havent used a cd since 2010. i would rather upload to a usb stick and plug and play


----------



## drez

Quote: 





ultrabike said:


> Hope they are not charging 20% re-stocking fee. But don't worry mang,  for < $350 you could still get:
> 
> http://www.amazon.com/Behringer-FBQ2496-Suppressor-Parametric-Equalizer/dp/B000KIPT26/ref=sr_1_1?s=musical-instruments&ie=UTF8&qid=1345185896&sr=1-1&keywords=FBQ-2496
> 
> ...


 
   
  That is a pretty sweet list, esp the Marantz CD player.  I am dying to compare my computer setup to a decent quality CD transport - I have put a lot of work into my music server...
   
  USB cables IMO are hit and miss - some $1500 cables sound worse than $300 ones, other $150 cables worse than $10 cables.  I think the problem is the 90 Ohms - you can't really cheat it and lots of manufacturers have come up with a myriad of other aspects they can try to "improve" upon but never tend to mention the magnitudes of the differences they make.  At least with money back thing there is less of a risk.  Also worth noting is I have found that the solder seems to need burn in for some strange reason (sounds warm and smooth at first but this goes away) - that or some sort of brain burn in occurs...  Took my latest cable about a week of playing maybe 4-6 hours a day to settle down (or for my brain to adjust to).


----------



## danne

Quote: 





bigshot said:


> All CD players that are operating to specs sound pretty much the same. I've done the comparisons myself with CD players, SACD players and iPods. Put the same exact audio file in them, line up the levels and you'll have a great deal of trouble ever telling them apart without peeking.
> Not everyone could tell you that, but not everyone goes to the trouble to test their gear like I do.


 

 If that is your conclusion you should be happy, or atleast your wallet. 
	

	
	
		
		

		
		
	


	



  Personally I think there is a huge diffrence in sources and would not go back to getting the audio straight out of the mac mini.
  I do  think quite alot of people on this forums takes their time and testing gear, it's after all quite a big part of the forum to share your experience of your finds on the "audio-journey".


----------



## ultrabike

Quote: 





drez said:


> That is a pretty sweet list, esp the Marantz CD player.  I am dying to compare my computer setup to a decent quality CD transport - I have put a lot of work into my music server...


 
   
  I think so. I also would not dismiss something like this (depending on your requirements & needs):
http://www.amazon.com/Pioneer-Dv610av-s-Upconverting-DVD-Audio-Playback/dp/B001CF6B32/ref=sr_1_4?s=electronics&ie=UTF8&qid=1345221163&sr=1-4&keywords=sacd


----------



## bigshot

Danne... You would be surprised how many people judge sound quality by file size and never bother to actually set up a line level matched A/B comparison. They go with what they think seems to make sense.

You're in the Sound Science forum right now though, and you're mixing with people who have a desire to know, and not just think. My personal experience is that 24 bit is identical to redbook for normal music playback and that all CD players that are performing to spec sound the same... I'm not alone in this. My conclusions have been confirmed by other people here who have taken the time to find out for themselves.

It's easy to think 24 bit sounds "night and day" better than redbook if you haven't played a CD in three years. It's easy to think that lossless sounds better than a high bitrate LAME MP3 if you've always just ripped to lossless and only have a few low bitrate files friends gave you. And it's easy to think every CD player sounds different if you've only ever owned one CD player at a time. But none of these things are true.

I'm really not arguing here. I'm sharing facts that I have done the legwork to find out. Feel free to set up your own test and check my results if you'd like. I'd be happy to share tips to help you set up a really clear test. I know what you'll find out. I've had thirty years in this hobby, and I've produced sound for release on CD and television. It's not like I don't know what I'm talking about.

If you want to learn, you do that by finding people who know more about a subject than you do and pick their brain for info you can use. You don't gain anything by just contradicting them without any basis. Personally, I like to learn, and I've found a few really good sources of information in this forum. That's why I'm here.


----------



## bigshot

I had an inexpensive Pioneer DVD/Bluray player like that and it was fine for audio, but for some reason, it was incapable of passing 1080 progressive to my Epson video projector through HDMI. We tried everything and it always interlaced. I ended up just buying a cheap Sony to replace it and it not only delivered 1080p, it was less prone to errors in playing disks and it had a much better remote.


----------



## ultrabike

Quote: 





bigshot said:


> I had an inexpensive Pioneer DVD/Bluray player like that and it was fine for audio, but for some reason, it was incapable of passing 1080 progressive to my Epson video projector through HDMI. We tried everything and it always interlaced. I ended up just buying a cheap Sony to replace it and it not only delivered 1080p, it was less prone to errors in playing disks and it had a much better remote.o


 
  Possibly a handshake issue on an early model. FWIW that one is a multi-region up-converting DVD/DVD-Audio/SACD player (no Blu-Ray) with a 192kHz/24-bit DAC (to support the SACD format.) If no SACD playback requirement, and Blu-Ray playback required, may be better to get something else 
	

	
	
		
		

		
		
	


	



   
  Personally I got this for parents:
http://www.amazon.com/Panasonic-DMP-BDT210-Integrated-Wi-Fi-Blu-ray-Player/dp/B004G8HXXO/ref=sr_1_1?s=electronics&ie=UTF8&qid=1345226607&sr=1-1&keywords=bdt210
  since they had no SACD requirements and it did most of what they needed. It loaded fairly fast and picture quality was great IMO. I don't think we paid more than $150 for it.
   
  Which Sony player (model) did you end up getting?


----------



## bigshot

They aren't making my Sony any more (natch!) it cost $120 though. That's easier to sort out than model numbers.

The new Sony bluray players also play SACDs, so they make a good all in one solution.


----------



## Griploc

When you take away 16 bits of sampling from a 24 bit audio .wav file frequencies are chopped and slightly distorted. A dither is then used to smoothen out the harsh distortion or chopped frequencies. It cant sound identical. It loses frequencies modtly in the upper hf content. I took a very detailed course on the subject in college when studying audio engineering and music production back in 2008. I have also had 11 years recording mixing and mastering experience. I dont want to say that it doesnt sound close the 24 bit file because i wouldnt know but it is impossible in fact to be identical sounding because you lose 1/2 of the sampling bits.


----------



## Griploc

Personally a dvd would make sense to be burning audio onto imo


----------



## bigshot

The principle difference between 16 bits and 24 is the dynamic range and depth of the noise floor. Frequency response on both cover the full audible spectrum. If you use the proper dither, there is no audible impact on the sound bouncing it down. Do some googling. Your school didn't give you the straight dope on this.


----------



## ultrabike

Quote: 





bigshot said:


> The principle *difference between 16 bits and 24 is the dynamic range and depth of the noise floor*. Frequency response on both cover the full audible spectrum. If you use the proper dither, there is no audible impact on the sound bouncing it down. Do some googling. Your school didn't give you the straight dope on this.


 
   
  Yup.


----------



## mikeaj

I guess you could call it chopping frequencies, taking a loose definition and wrangling things around?  Suppose you have a really really really quiet sine wave (any frequency of your choice) with amplitude represented in the 8 least significant bits with 24-bit samples.  Once you convert to 16-bit samples, then that sine wave is gone.  So that can happen at any frequency. 
   
  But honestly, these are issues of noise and dynamic range.  You really need some relatively extreme circumstances—high listening volume, cranked up gain because average levels are so low, quiet listening environment—to be able to hear the digital noise floor for 16-bit playback.  Considering the best SNR you can get with microphones in the recording studio (far under 96 dB or so), usually there's some noise in the recording itself that would be above the digital noise floor, so is there much of a point?
   
  Anyway, there are plenty of threads on this already.


----------



## bigshot

I did the math. In order to hear the difference between 24 bit and 16 bit using speakers in a living room, you would have to turn the volume up high enough that it would be as loud as standing a few yards from the engines of a 747 as it takes off. Hearing damage time.


----------



## billybob_jcv

Quote: 





bigshot said:


> I did the math. In order to hear the difference between 24 bit and 16 bit using speakers in a living room, you would have to turn the volume up high enough that it would be as loud as standing a few yards from the engines of a 747 as it takes off. Hearing damage time.


 
   
  Yeah, but at 24 bits you can tell the difference between a 747-400 and 747-8...


----------



## Griploc

Thank you for correcting me. I jumped the gun too quickly when i replied to your response. Still there is a difference in sonicality, I prefer to losten to headphones when at home and i listen to loud levels but i mostly compare my mixes from 24 bit wav to 16 bit 320 kps mp3 formats because my clients prefer to have the mp3 format to upload to itunes or any other online store.


----------



## Griploc

My goal is to have the mp3 format as good as the wav format every render


----------



## mikeaj

Quote: 





bigshot said:


> I did the math. In order to hear the difference between 24 bit and 16 bit using speakers in a living room, you would have to turn the volume up high enough that it would be as loud as standing a few yards from the engines of a 747 as it takes off. Hearing damage time.


 
   
  What were the calculations?
   
  Even in Meyer/Moran (though according to many, _nothing_ is to be believed there 
	

	
	
		
		

		
			





 **), when they added 14 dB to their listening level (resulting in an "often unbearably" loud level), then people could identify the 16-bit A/D/A loop 10/10.
   
  Granted, that's the noise combined from the hi-rez system, the A/D, and the D/A.  The A/D/A loop had no noise shaping, too.  Also, the test was with no input, so there's no signal to mask anything.  With a signal, any noise would be much much harder to hear—and again, there is going to be noise in most music content as a result of the recording process.
   


Spoiler: Warning%3A%20**



Though I would be more careful than some in terms of conclusions drawn.  There are extensive and meaningful results, but it is possible to have a more sensitive test regimen, maybe cranked volume would make differences easier to hear, and so on.  What happened is just a large number of A/B/X tests performed on a large number of test subject in a certain fashion in a variety of good listening conditions with a good setup.


   
   


griploc said:


> My goal is to have the mp3 format as good as the wav format every render


   

   
  What mp3 encoder?  There's obviously going to be some additional information lost as the result of the lossy encoding, but even those need not necessarily be audible at all.  Anyway, do the comparison blinded, if you haven't already—that's easy to do with just two different music files.


----------



## Griploc

I use the waves dithers mostly with the L316


----------



## bigshot

griploc said:


> i mostly compare my mixes from 24 bit wav to 16 bit 320 kps mp3 formats because my clients prefer to have the mp3 format to upload to itunes or any other online store.




I've done tests on MP3s too, and I found that not all MP3 encoders are the same. ITunes is fantastic at creating great sounding AAC files, but it isn't very good at creating MP3s. Encoding in LAME is much better, and sounds as good as the Redbook.


----------



## bigshot

mikeaj said:


> What were the calculations?




It was a shirtcuff calculation. I took the 90dB of CD sound, added 25dB to overcome the noise floor of the average living room, then added another 15 or 20dB so the difference would be raised above the edge of the edge of the noise floor. That's around 130dB... Woodchipper time!

However, since most music doesn't use more than 45dB or so, you can feel free to add another 45dB to bring the noise floor of redbook up to the music's level. Are ya bleeding from the ears yet?


----------



## Griploc

I use either protools mp3 encoder or itunes. I personally prefer itunes


----------



## Typhoon859

Maybe I missed it but there is something that's not being addressed which I would like to inquire about. 
   
  I've been reading things here and there about USB because of many strange things I've experienced in the past - details like phones not charging with some but charging with others, strange inconsistencies with different sources of power supply with different cables, and a while ago I remember coming across somebody making a claim that their DAC/AMP sounds better with a certain cable over another, saying that the other cable provides more power.  To be honest, in general I've learned absolutely nothing.  Everybody argues against the other and it's incredibly confusing.  All I know is, there is a digital signal; there is a power signal; past certain distances you need power hubs and/or thicker cables. 
   
  Now, my question roots from this person's claim and furthermore after hearing that the FiiO E17 amp I have is powered by USB somehow and it works differently than through S/PDIF - that the power drawn through USB when connected is important.  There are many reasons that doesn't make sense to me, but that's maybe because of certain unfounded assumptions on how the device works and maybe because I don't really know what I'm saying past what I can logically infer from what's right in front of me.  All I know is, the power supply makes a difference (like what kind of battery is used as any company for portable audio needs to debate).  I always assumed that the best voltage/current was determined and whatever necessary amount of energy was drawn - difference between the sources simply being how fast they drain.  Apparently not, SO, *could a USB cable which sup**plies more power to a DAC/AMP combo result in a fuller sound?  *
   
  Digitally, if I don't hear any breaks/skips, I really don't see how the sound could be affected unless audibly obvious in some other way.  I have a bunch of these cables lying around everywhere and I see no reason why I shouldn't just grab a random one that transmits the data without a hiccup besides if it affects anything to do with power.


----------



## ultrabike

Quote: 





typhoon859 said:


> *could a USB cable which sup**plies more power to a DAC/AMP combo result in a fuller sound? *


 
  USB cables do not generate power, they merely "transport" it.
   
  A stock and cheap USB cable I have is able to supply 1 amp to my 500G hard drive from my laptop so that it can spin. If the source is my NAS, the 500G will not spin, but that's because my NAS can only supply 500mA to the hard drive. In other words, the power supplied to your DAC/AMP combo is probably more dependent on your power source than your USB cable.


----------



## OJNeg

Quote: 





ultrabike said:


> USB cables do not generate power, they merely "transport" it.
> 
> A stock and cheap USB cable I have is able to supply 1 amp to my 500G hard drive from my laptop so that it can spin. If the source is my NAS, the 500G will not spin, but that's because my NAS can only supply 500mA to the hard drive.* In other words, the power supplied to your DAC/AMP combo is probably more dependent on your power source than your USB cable.*


 
   
  As far as I know, a USB source from something like a laptop port will deliver around 100mA. From a desktop mobo or a USB hub with a dedicated power supply, it can be much more.


----------



## ultrabike

AFAIK the Dell E1505 can supply 1 amp, otherwise my WD 500G portable wouldn't have worked:
   
http://www.readynas.com/forum/viewtopic.php?f=31&t=35826&p=203284&hilit=usb#p199504


----------



## OJNeg

It probably varies heavily between laptops. And every other device on the market for that matter.


----------



## liamstrain

Quote: 





typhoon859 said:


> *could a USB cable which sup**plies more power to a DAC/AMP combo result in a fuller sound? *


 
   
  There should be no  change to the signal transmitted. However... IF the Dac/Amp relies on the USB power to power the amplifier circuit, it is possible that with some lower sensitivity headphones, it will have more juice, effectively - and can power them better (effectively stepping up the power source). The M3, for instance, has different power ratings, depending on the power supply you use with it. 
   
  This does not affect the signal - but does affect the ability of the amp to power more difficult headphones, which *could* theoretically, result in fuller apparent sound (higher volume for the same setting). 
   
  But this is a function of how much power is being provided by the USB output (computer v. hub, etc.) - and the cable itself would have very little impact over normal distances.


----------



## joeyjojo

Depending on the component there may be a difference between say USB and TOSLINK, e.g. the CA Dacmagic performs far worse with USB than other transports http://www.stereophile.com/content/cambridge-audio-azur-dacmagic-da-converter-manufacturers-comments
   
  I'd bet a good amount of money that if I crept into Lorspeaker's house and swapped that expensive cable for a cheap one he'd never notice


----------



## Lorspeaker

u wont get pass my anti-junkstockcable detector...


----------



## Lorspeaker

ok just to enthuse myself..
  i just put back my stock usb and played FOURPLAY...
  and it sounded like this..
   
   (((  
	

	
	
		
		

		
		
	


	




  )))
   
   
   
  then i swapped back my branded usb....
  and FOURPLAY sounded like this
   
*(((      *



*       )))*
   
   
   

   
   
   
  Just did a test on the first song of PURE by Hayley Westenra....
  on the stock usb, she was singing in a classroom,
  on the branded usb, she was surrounded by mountain spring 




   
  1.30 minutes into the song, when the chorus joined in,
  i wanted to walk out of the classroom on the stock usb...just too crowded...
  but i stayed to play in the waters with the branded usb on.


----------



## bigshot

Those braided wire covers create a mountain stream! Yoo kwazy!


----------



## germanium

Quote: 





joeyjojo said:


> Depending on the component there may be a difference between say USB and TOSLINK, e.g. the CA Dacmagic performs far worse with USB than other transports http://www.stereophile.com/content/cambridge-audio-azur-dacmagic-da-converter-manufacturers-comments
> 
> I'd bet a good amount of money that if I crept into Lorspeaker's house and swapped that expensive cable for a cheap one he'd never notice


 
   These jitter tests are done in the analog domain & as such noise can interfere as they did here in the jitter test with the switch mode power supply connected. This is not true jitter even though it may appear to be so. It is power supply hash that gets through as a result of poor filtering or regulation. The native jitter of the device in test on battery was very low. This jitter was buried by the noise of the power supply. If one wants to know the true jitter of the clock one needs to measure the clock & only the clock. Measuring in the analog domain opens you to too many other issues. If one were to measure the actual on board clock of the device in question you would find the jitter quite low in most cases, far below any analog measured jitter. It is this clock that the DAC goes by as the data is buffered & released by this local clock. The manner in which data is transfered by usb would probably add some noise not to be confused with jitter as it is transferd in bursts as are all computer transfers. though with USB1.0 spec the bursts come veryu close to the actual data requirements which with poor regulation & noise filtering in the powersupoply can possibly cause a disturbance of the clock by having small powersupply related spikes riding on it. There is a difference in load to the power supply as to when there is a transfer & when there isn't a transfer taking place however small it may be. Some device power supplies handle it well & some may not. Obviously the laptop in question did not & power supply noise was likely present tn the USB bus appearantly in fairly large quantity.


----------



## bigshot

What you're saying is, there are much bigger things to deal with than jitter.


----------



## Lorspeaker

Quote: 





bigshot said:


> Those braided wire covers create a mountain stream! Yoo kwazy!


 
   
  hehehehehehehehehehehehehehehehehehehehehe...i had a few whisky..pardon me. 
  back to my frolicking in the waters.


----------



## ultrabike

Quote: 





germanium said:


> These jitter tests are done in the analog domain & as such noise can interfere as they did here in the jitter test with the switch mode power supply connected. This is not true jitter even though it may appear to be so. It is power supply hash that gets through as a result of poor filtering or regulation. The native jitter of the device in test on battery was very low. This jitter was buried by the noise of the power supply. If one wants to know the true jitter of the clock one needs to measure the clock & only the clock. Measuring in the analog domain opens you to too many other issues. If one were to measure the actual on board clock of the device in question you would find the jitter quite low in most cases, far below any analog measured jitter. It is this clock that the DAC goes by as the data is buffered & released by this local clock. The manner in which data is transfered by usb would probably add some noise not to be confused with jitter as it is transferd in bursts as are all computer transfers. though with USB1.0 spec the bursts come veryu close to the actual data requirements which with poor regulation & noise filtering in the powersupoply can possibly cause a disturbance of the clock by having small powersupply related spikes riding on it. There is a difference in load to the power supply as to when there is a transfer & when there isn't a transfer taking place however small it may be. Some device power supplies handle it well & some may not. Obviously the laptop in question did not & power supply noise was likely present tn the USB bus appearantly in fairly large quantity.


 
   
  It seems the Cambridge audio DAC USB receiver had some issues dealing with data jitter according to JA's measurements (Fig. 12 @ http://www.stereophile.com/content/cambridge-audio-azur-dacmagic-da-converter-measurements.) Seems the Peachtree iDac did a little better: http://www.stereophile.com/content/peachtree-idac-da-converter-measurements.
   
  I personally doubt swapping the USB cable would have made a significant difference. If that was the case, I bet Cambridge Audio would ship usbmagic cable along with it's Dacmagic as well, as part of their jitter reduction scheme...


----------



## LFF

Hey people...ultrabike heard my uber awesome audiophile USB cable at the LA meet. He can tell you how awesome my rig sounded with that cable!!!


----------



## ultrabike

Quote: 





lff said:


> Hey people...ultrabike heard my uber awesome audiophile USB cable at the LA meet. He can tell you how awesome my rig sounded with that cable!!!


 
   
  Was that what it was!!!? WOW. That cable is an exception to the rule! With that USB cable the sound stage spread-eagled. Otherwise piercing highs were dominatrixly tamed. Muddy lows were nun tighten. Sucked mids were ... brought forth. Was it the super conductive phoenix feather metal alloy core that did the trick?


----------



## mikeaj

Quote: 





ultrabike said:


> I personally doubt swapping the USB cable would have made a significant difference. If that was the case, I bet Cambridge Audio would ship usbmagic cable along with it's Dacmagic as well, as part of their jitter reduction scheme...


 
   
  Nah, the cable companies all have secret tech that none of the other audio component manufacturers can understand or replicate, and they're all too cheap to bundle the goods with the secret-sauce cables, so they send us cheap stock cables that are in desperate need of replacement!  I'd DIY the cables myself, but I don't have any pixie dust handy...


----------



## drez

being smug is so cool...


----------



## Lorspeaker

Quote: 





ultrabike said:


> Was that what it was!!!? WOW. That cable is an exception to the rule! With that USB cable the sound stage spread-eagled. Otherwise piercing highs were dominatrixly tamed. Muddy lows were nun tighten. Sucked mids were ... brought forth. Was it the super conductive phoenix feather metal alloy core that did the trick?


 
   
  its the whisky.....


----------



## LFF

Quote: 





lorspeaker said:


> its the whisky.....


 

 LOL!


----------



## AKG240mkII

Quote: 





lorspeaker said:


> hehehehehehehehehehehehehehehehehehehehehe...i had a few whisky..pardon me.
> back to my frolicking in the waters.


 
  http://www.hear-it.org/Alcohol-can-cause-hearing-loss
   
  ( No, it's not a joke ! )


----------



## Typhoon859

ultrabike said:


> USB cables do not generate power, they merely "transport" it.
> 
> A stock and cheap USB cable I have is able to supply 1 amp to my 500G hard drive from my laptop so that it can spin. If the source is my NAS, the 500G will not spin, but that's because my NAS can only supply 500mA to the hard drive. In other words, the power supplied to your DAC/AMP combo is probably more dependent on your power source than your USB cable.




I understand the cable itself doesn't generate the power. What I am saying though is that certain cables transfer less than what they should. If all USB cables transmitted power equally, then it wouldn't matter what cable was used for any device. But, depending on the device, certain cables provide enough to charge/power it while some don't. That's the whole basis for my question. To be honest, my question is also directly in relation to the FiiO E17 DAC/Amp and how it functions so if I can rephrase the question more specifically... For the E17, would a cable that transmits more power from the source effectively drive the sound better? Would a higher output even from the source make a difference? I always thought the E17 was driven by its battery the same from any source and that the power transmitted through the USB just charged it (the only factor being whether more or less efficiently). Can anyone sort this out for me? I really don't have the knowledge to do so on my own. If the question can be answered for something like the E10 which is 100% driven by the USB supply, that would be great too. 

PS- When I say fuller sound, I mean the effect that a good amp has on the signal at equal loudness relative to another. An amp I've found has a significant effect on neutral cans with a large soundstage, not necessarily at all hard to drive. E.g., an iPad has significant amping to drive my Brainwavz HM5's as loud as I could possibly want but through line out and a FiiO E11 amp, it sounds SIGNIFICANTLY better (fuller - more alive, or in stricter terms, more presence and dynamics in the mids and bass).


----------



## TickleMeElmo

Quote: 





typhoon859 said:


> t a good amp has on the signal at equal loudness relative to another. An amp I've found has a significant effect on neutral cans with a large soundstage, not necessarily at all hard to drive. E.g., an iPad has significant amping to drive my Brainwavz HM5's as loud as I could possibly want but through line out and a FiiO E11 amp, it sounds SIGNIFICANTLY better (fuller - more alive, or in stricter terms, more presence and dynamics in the mids and bass).


 
   
  That's somewhat different in two key ways:
   
  A. You cannot say that it sounds better out of the E11 unless you double blind test it with a reasonable confidence interval (i.e. not try it 4 times and if you guessed right 3 times call it a day).
   
  B. The circuitry in the iPad is limited and it may not provide the same wattage at different frequencies and other factors. This is less about the iPad not having enough power to drive it, it's more about the iPad not being designed for completely faithful reproduction throughout the entire frequency spectrum.


----------



## astroid

Isnt it the ports that supply the power and the ports that have differences in the voltage they supply, the cables will transfer what they are fed?  


typhoon859 said:


> I understand the cable itself doesn't generate the power. What I am saying though is that certain cables transfer less than what they should. If all USB cables transmitted power equally, then it wouldn't matter what cable was used for any device. But, depending on the device, certain cables provide enough to charge/power it while some don't. That's the whole basis for my question. To be honest, my question is also directly in relation to the FiiO E17 DAC/Amp and how it functions so if I can rephrase the question more specifically... For the E17, would a cable that transmits more power from the source effectively drive the sound better? Would a higher output even from the source make a difference? I always thought the E17 was driven by its battery the same from any source and that the power transmitted through the USB just charged it (the only factor being whether more or less efficiently). Can anyone sort this out for me? I really don't have the knowledge to do so on my own. If the question can be answered for something like the E10 which is 100% driven by the USB supply, that would be great too.
> PS- When I say fuller sound, I mean the effect that a good amp has on the signal at equal loudness relative to another. An amp I've found has a significant effect on neutral cans with a large soundstage, not necessarily at all hard to drive. E.g., an iPad has significant amping to drive my Brainwavz HM5's as loud as I could possibly want but through line out and a FiiO E11 amp, it sounds SIGNIFICANTLY better (fuller - more alive, or in stricter terms, more presence and dynamics in the mids and bass).


----------



## liamstrain

typhoon859 said:


> I understand the cable itself doesn't generate the power. What I am saying though is that certain cables transfer less than what they should. If all USB cables transmitted power equally, then it wouldn't matter what cable was used for any device.


 
   
  Within the "normal" USB 2 standard specs, the length of the USB cable should never be so long as to have this be an issue. And to date, I've not seen any USB 2 rated cable (as even the cheapest monoprice cables are) that had power issues. Do you have data or specific examples of this being the case?
   
  I HAVE seen non-standard USB ports, which did not provide enough power. But this is unrelated to the cable's ability to transport it.


----------



## OJNeg

Remember folks, wire is wire. As long as the cable itself is to spec, there will be no difference in how the receivers interface or how much power it will transfer. Look at the pin-out for a standard USB cable.
   
  http://en.wikipedia.org/wiki/USB
   
  For USB 2.0, there are 4 pins as you can see. V+, D-, D+, and GND. You wouldn't even need the two data pins if only powering a device through USB. I could jerry-rig two wires to the V+ and GND pins and I would still be able to get power.
  
   
  Quote: 





astroid said:


> Isnt it the ports that supply the power and the ports that have differences in the voltage they supply, the cables will transfer what they are fed?


 
   
  There shouldn't be any differences in voltage. USB is 5V standard. Even a low-powered USB port shouldn't deviate (too much) from this, or else the device might not even turn on. The difference lies in the current available. And since P = VI, more current gives you more power.


----------



## Typhoon859

I can't believe all the responses are questioning the little that I mentioned.  I DON'T KNOW, that's why I'm asking you guys.  To be honest I can't feel but a bit insulted but then again, I'm just some random guy and nobody could really know to the extent to which I tested any of this.  I won't repeat any of what I said.  I will only say that I am certain of it all; I am aware of all the phenomenon that could've compromised my judgment.  At the very least for now, for the purposes of figuring out the rooted factor in all of this, try to answer the questions under the assumption that what I mentioned is inherently true.  Like...
   
  In terms of the sound from the FiiO E11 amp vs. the iPad's, it is 100% not placebo - there is a very significant difference.  There are cases where I'd need to make sure, trying to blindly see if there are any subtle differences; this isn't one of them.  It's simply a better designed amp and a more powerful one, driving the mids and lows more evenly relative to anything going higher in frequency.  I can't tell you what those differences could be in design and why/in what way the iPad's e.g. is flawed, but the iPad's volume is limited to loudness in Treble while through the amp the harder to drive frequencies relative to the higher ones are done so evenly and the volume isn't limited in that way.  Consider that my technical explanation, lol. 
   
  In terms of the cables, like I said, unless I have many many MANY cables that randomly don't meet the standard (I have many cables XD), then clearly there's something more involved than poor design being the reason that the power isn't being fully transmitted.  This is randomly true in combination with different sources, different devices, and different cables, as in, with some sources certain cables work for a device while others don't.  In another source, some of those same cables may work for the device but some may not and others do.  I always thought it just had something to do with resistance.  And I mean, everyone I know has run into this problem at least once, not even trying to test anything.  They just didn't think much of it/didn't care, used a different cable, and that was that.  I wouldn't care enough to delve into all the complexities myself if it were just a matter of a device charging or not; I'd also just switch to a cable that works and move on.  In this case though, there's the potential that it affects quality and considering probable differences in it, I need to know. 
   
   
  I'm trying to find out if for prior mentioned devices, if difference in power transmitted could lead to better "quality" (as has been defined), so, let's make this EVEN simpler, sigh..
   
  (>Power --> amp = >Quality)?
  (More efficient cable --> amp = >Quality)?  <-----This could obviously still be debated but I've told my experience and I thought it was a common
                                                                      one. There's no other explanation and it's not like I've acquired all the "weird cables" of the world.
                                                                      Maybe there's a way to test the power transmitted through the cables; maybe some sort of device?
   
  People here are doubting if a better amp could even lead to an improvement in quality (at the same levels) which clearly it can since one can be designed in a great number of ways, especially with compromises like for ones which are integrated into portable multi-functioning devices such as an iPad.  So, I have a feeling like with anything else audio related, I won't ever get an answer - certainly not a straight one.  This is like the least freakin' scientifically treated field I've ever seen.  Nobody knows crap about anything and just applies their personal assumptions based on random observation/theory they've learned that they think may apply.  We'll never be able to move on to the next problem and the next if nothing before is established.  Every time I ask something that's dependent on a factor prior, the factor prior is contested because everyone still disagrees on the elementary.  You can't do the root of something if you can't agree on how to multiply...
   
  Look at Psychology.  They've been able to establish grounds for a large assortment of problems based on similar testing.  Why can't we?  Psychology has even less information to go on.  We have the entire field of Electrical Engineering.  I understand that couldn't have happened in the field through forums and talks like this but the information I look for doesn't seem to be remotely universal even in the professional world.  So frustrating...  I already isolate myself by nature and this only adds to this problem which provokes the idea of reinventing the wheel about every little thing I wish to figure out, isolating you into individualized testing for every minor thing.  This is in fact a scientific field and yet nobody gets together to do thorough, long, really involved research that leads to conclusive results that people can learn from.  Nowhere else do students EVEN THINK to argue something like a pretty cable in fact making a difference over an ugly one which really works just as well because it's understood as being founded knowledge being taught.  Of course that's exaggerated but it's only in dreams where it isn't like this to any extent of a degree.  Then again, not many people even dream about it unless they're intent on learning this BS like many of us are through our interest.  At best, people conform to all the wrong unfounded ideas and I'm starting to not see a difference between them and us so-called "audiophiles".  I'm not speaking for myself btw..
   
  Sorry about the rant.  It's just so exhausting already...
   
   
  Quote: 





ticklemeelmo said:


> That's somewhat different in two key ways:
> 
> A. You cannot say that it sounds better out of the E11 unless you double blind test it with a reasonable confidence interval (i.e. not try it 4 times and if you guessed right 3 times call it a day).
> 
> B. The circuitry in the iPad is limited and it may not provide the same wattage at different frequencies and other factors. This is less about the iPad not having enough power to drive it, it's more about the iPad not being designed for completely faithful reproduction throughout the entire frequency spectrum.


 
   
  Quote: 





astroid said:


> Isnt it the ports that supply the power and the ports that have differences in the voltage they supply, the cables will transfer what they are fed?


 
   
  Quote: 





liamstrain said:


> Within the "normal" USB 2 standard specs, the length of the USB cable should never be so long as to have this be an issue. And to date, I've not seen any USB 2 rated cable (as even the cheapest monoprice cables are) that had power issues. Do you have data or specific examples of this being the case?
> 
> I HAVE seen non-standard USB ports, which did not provide enough power. But this is unrelated to the cable's ability to transport it.


----------



## liamstrain

Quote: 





> At the very least, try to answer the questions under the assumption that what I mentioned is inherently true.


 
   
   
   
   
No - that's not the way science works. Especially when the concept in question is not at all likely to be true. I have never run into this problem, with the exception of one broken cable. But let's say what you are experiencing is inherently true - we still have not determined it is the cables that are at issue - they may only be a trigger for an equipment fault, or it could be entirely coincidence. Without objective testing, we cannot know. 
   
   
   


> This is like the least freakin' scientific field I've ever seen.


 
   
   
No - you are expecting science to say things it cannot with the evidence so far provided. And the people in the best position to do the research (the product manufacturers themselves), have no vested interest in doing so, since most of it will put them out of business. 
   
   


> Maybe there's a way to test the power transmitted through the cables; maybe some sort of device?


 
   
   
Any reasonably sensitive multimeter with an appropriate adapter plug, will give you readings from the USB port, and then from the cable, to compare. I have not done such a test, but there is little reason to suspect that a short length of cable like this will show any appreciable power loss. 
   
   
   


> In terms of the sound from the FiiO E11 amp vs. the iPad's, it is 100% not placebo - there is a very significant difference.


 
   
   
  It is especially in the "obvious" differences that we need to double check ourselves using objective methods. Blind testing is not just for subtlety. I actually don't doubt you on this call, but I do doubt the reasons for the difference - I suspect that FiiO uses some internal eq to generate an artificially fuller sound, and actually does modify the signal, rather than just amplify.


----------



## bigshot

typhoon859 said:


> At the very least, try to answer the questions under the assumption that what I mentioned is inherently true.




If you wanted us to humor you, you should have said that at the beginning, and I could have just said I'm sure your unusual USB cable is very nice.


----------



## Typhoon859

Quote: 





liamstrain said:


> No - that's not the way science works. Especially when the concept in question is not at all likely to be true. I have never run into this problem, with the exception of one broken cable.
> 
> 
> 
> ...


 
  I understand that.  There was a specific bit of scientific data that I was looking for and that's what I wanted to know.  I mentioned what that is.  All that was involved was getting in the way so the point of what I was saying was for the idea to be isolated in context.  I further said that about the cables, it's still debatable; I said that!..  I haven't evaluated the problem using actual data, just careful observation based on the results.  It's why I'm asking.  It's not like I've been given a likely reason as to why this might be.  Do I go against the possibility of there being some other issue I'm overlooking?  All I said was that based on the extensive results, I can't think of and no other factors were brought up that could be affecting what I've experienced.
   
  Wow, you guys really make it difficult don't you?  Can we talk on level with each other please?  What kind of BS is you telling me what I'm expecting from science.  I can't even comment on that.  If there's something you'd like to mention, mention it, but do so without spontaneous aggression; doesn't matter what nonsense gets stirred in your head.  Try to be objective.  Please don't push past my breaking point - or anyone's really.  A month ago with me, we would've already been there.  How do you expect me to respectfully phrase things especially after you just took everything I said, put it in a bag of s***, and through it at my face, and then proceeded to make a comment.
   
  Justification behind why many things in the field are uncertain is ironic at best.  The point is that it is and it's an issue, as would be for any scientific practice.  To be honest, I thought I'd actually get some sympathy in this regard because all of you seem to be squirming with this as well.  Nobody here has a sense of unified understanding behind one concept or another.  Maybe I'm overlooking the fact that everyone thinks they know best and don't think of the possibility that they could actually learn so it's like trying to say to sheep that they're all alike and them trying to individualize themselves with defensiveness even though the issue is larger than that which even has to do with them.  I wasn't isolating any of you guys about the overarching issue.  I don't know why it's like this but the point is that it is.  Any other profession, there are much fewer things, especially to this basic a nature, that are so difficult to get to the bottom of and move on, while here, never ending controversy.  How many decades has it been?
   
   
  Quote: 





bigshot said:


> If you wanted us to humor you, you should have said that at the beginning, and I could have just said I'm sure your unusual USB cable is very nice.


 

 Did you read anything else from what I've said?  Big shot, was it necessary to take this path?  What I was trying to say with that is if it's a problem otherwise to try and answer assuming there were differences in the power transmitted through cables, then take that factor out of the equation for now, point being to establish whether it even matters in the end regarding this.  Is it necessary to be anal about everything?  Do you not have the capability to expand on a thought?
   
  What does that even mean?  What USB cable of mine is even nice?  When did I ever even?...  Right, ok..  It matters not what I say, people like you will still come around.  I won't get any more specific than that   If you have nothing to say, then ignore this and engage where you do.  I'm sorry, were you insulted?  Really?..  Or did you just feel like being an ass?


----------



## liamstrain

> What kind of BS is you telling me what I'm expecting from science.  I can't even comment on that.  If there's something you'd like to mention, mention it, but do so without spontaneous aggression; doesn't matter what nonsense gets stirred in your head.  Try to be objective.


 
   
   
   
My apologies if that is how it comes across, that really is not my intent. You were complaining about how unscientific this field is. I am just countering that it is, in fact, quite scientific. Most of the complaints about it seem (from most people, and I'm sorry if I lumped you into them) to come from a misunderstanding of what science does, how, and what if any conclusions can be drawn reliably.


----------



## Typhoon859

Quote: 





liamstrain said:


> My apologies if that is how it comes across, that really is not my intent. You were complaining about how unscientific this field is. I am just countering that it is, in fact, quite scientific. Most of the complaints about it seem (from most people, and I'm sorry if I lumped you into them) to come from a misunderstanding of what science does, how, and what if any conclusions can be drawn reliably.


 

 Oh, I actually forgot to address that misunderstanding because I felt it was taken to too personal of a level for that problem to even matter.  I think you misunderstood the fact that I'm trying to say that THIS IS a scientific field and it isn't treated as such.  That was the main thing emphasized and what that was all about.  It's the point I was trying to make and that it's frustrating that there weren't and aren't any collaborative efforts to make the information unified rather than atomized as it is now where each person tries and put it together differently.
   
  That's why I brought up Psychology where this isn't the case, where the efforts are focused correctly, and where it's actually even harder a thing to do in that field than it would be here considering this is a field we ourselves created with Electrical Engineering.
   
  Hopefully somebody can provide some more insight.  I hate when it goes off the point with meaningless squabble about largely irrelevant ideological ideas.  I seriously only even mentioned any bit because I felt it's something everyone here would sympathize with considering their struggles - not remotely something that could stir up conflict.  But yeah, it's ok.  Thanks for clarifying.


----------



## liamstrain

Hah. A misunderstanding of a misunderstanding. My apologies.


----------



## Typhoon859

It's all good.
   
  EDIT: I fixed up some of the wording so that maybe it won't possibly come across in such a way.


----------



## bigshot

typhoon859 said:


> What I was trying to say with that is if it's a problem otherwise to try and answer assuming there were differences in the power transmitted through cables, then take that factor out of the equation for now, point being to establish whether it even matters in the end regarding this.




You're asking us to give you reasons why your USB cable is better than another USB cable. I don't believe it is any better, and I can't think of reasons why it might, because everything about how a USB cable works indicates that there shouldn't be a difference.

You've reached a conclusion and your looking for evidence to prove it after the fact. You're doing it backwards. First gather the evidence, THEN come up with the conclusion. Most of us have already done that. I know enough about how cables work, and I've compared enough cables to reach a conclusion. I've also done controlled listening tests using the iPad and iPod and know your conclusions there aren't based on solid comparisons either.

If you want to ask for opinions from people with more experience than you have, you need to be prepared to accept their opinions. If you want to disagree, you need to do that from a position of knowing more than them, not less. I'm really not trying to be rude. I'm just stating the obvious.


----------



## Typhoon859

Quote: 





bigshot said:


> You're asking us to give you reasons why your USB cable is better than another USB cable. I don't believe it is any better, and I can't think of reasons why it might, because everything about how a USB cable works indicates that there shouldn't be a difference.
> You've reached a conclusion and your looking for evidence to prove it after the fact. You're doing it backwards. First gather the evidence, THEN come up with the conclusion. Most of us have already done that. I know enough about how cables work, and I've compared enough cables to reach a conclusion. I've also done controlled listening tests using the iPad and iPod and know your conclusions there aren't based on solid comparisons either.
> If you want to ask for opinions from people with more experience than you have, you need to be prepared to accept their opinions. If you want to disagree, you need to do that from a position of knowing more than them, not less. I'm really not trying to be rude. I'm just stating the obvious.


 

 No I'm not.  Where the hell did you even get that idea?  That my USB cable is better than another?  I've probably stated my only inquiry in 3 different ways and somehow you got that from it?  You're stating the obvious that's contrary to anything I've said.
   
  The way you're further characterizing what I think and what I'm doing is completely against the nature of how purposefully uncertain I even phrased everything from the first post for shielding against sensitive people like you which can't get around personal dilemmas to actually provide help instead of whatever you wanna call this stupidity.  Are you just absolutely dense or do you actually have something to gain from this?  Some subconscious insecurity maybe?  If you really think you're not trying to be rude then I honestly don't know what you've been reading.
   
  The only reason I'm even responding to you is because you're distracting from any possible productive replies.  My post is now buried behind this heap of nonsense and people will either not see it or conform to your dumbfounded interpretation of the post.  At first it's worth it to try and respond, as you can see from the result above.  But now it's too much.  I hope people just ignore this...  Thanks for watering down the possibility of a relevant to what's important, linearly given response to almost nothing. My only damn motivation to spend the time making these posts was to learn something.  Why can it never be avoided for it coming down to this?  I honestly don't even know where you could possibly be getting what you got.  Please let's move on from this.  If you're now unsure of what I was asking or anything, then just forget about it and disregard it.
   
  Wasted almost 4 hours since the beginning of trying to make that post on nothing...  I don't have any leisure time for bs like this.


----------



## dvw

Quote: 





typhoon859 said:


> I'm trying to find out if for prior mentioned devices, if difference in power transmitted could lead to better "quality" (as has been defined), so, let's make this EVEN simpler, sigh..
> 
> (>Power --> amp = >Quality)?
> (More efficient cable --> amp = >Quality)?  <-----This could obviously still be debated but I've told my experience and I thought it was a common
> ...


----------



## Typhoon859

Quote: 





dvw said:


>


 

 I understood this from the start.  That's the reason for my confusion...  That's why I'm wondering what the other factors could be which are actually making the difference (a lot of defective cables, the defective ones varying with source NOT being one of them).  I don't want to bring any possibilities up, at this point I think for obvious reasons, and I'm leaving the table open. 
   
  Plus, my question is more about the effect of more power going into an amplifier at this point, cable being less of a factor although there would still be that phenomenon to solve.  Plus, what you mentioned has been stated tens of times everywhere I looked which is the conclusion I logically also would come up with if I thought and understood that every cable is created on that basis, again, without there being the possibility for any other factors.  There are many people who argue for the opposite for many reasons.  The problem is that nothing is definitive here and just randomly applied theory assumed to be the best and only fit.  For your statement to have validity, it would need to be followed with something along the lines of, "unless this and this and this and this.."  Etc...


----------



## mikeaj

Quote: 





> Originally Posted by *liamstrain* /img/forum/go_quote.gif
> 
> 
> [snipped other text; below regarding FiiO E11]
> ...


 
   
  Just an unimportant FYI, but FiiO E11 and most of their amps have bass boost options, but the flat setting is pretty flat.  To be more specific, the super-cheap E3 has an always-on bass boost, and the E9 has 10 ohms output impedance (43 with the smaller jack), which would mean a significantly uneven response with some headphones and IEMs but not really any significant change with others.  E11 is within a 0.1 dB range from 20 Hz to 20 kHz and has very low output impedance.
   
  I'd first suspect a DC blocking cap or otherwise output impedance issues with the iPad, and (as stated) the E11 is definitely more powerful.  Also, as usual, level matching is key.
   
   
   
   


typhoon859 said:


> I can't believe all the responses are questioning the little that I mentioned.  I DON'T KNOW, that's why I'm asking you guys.  To be honest I can't feel but a bit insulted but then again, I'm just some random guy and nobody could really know to the extent to which I tested any of this.  I won't repeat any of what I said.  *I will only say that I am certain of it all; I am aware of all the phenomenon that could've compromised my judgment.*  At the very least for now, for the purposes of figuring out the rooted factor in all of this, try to answer the questions under the assumption that what I mentioned is inherently true.  Like...


 
  [emphasis added]
   
  To me, this is one of the biggest deals.  Being aware of said phenomena (mostly we're talking about expectation bias, but there are a lot of other variables to control for as well) and trying to account for that is not nearly enough to actually get unbiased results.  Sure, you can still get valid conclusions from biased data, but I wouldn't be so certain of the kinds of conclusions that people draw.  That's how life is, so that's why some people are skeptical.  It's nothing personal.


----------



## dvw

Quote: 





typhoon859 said:


> I understood this from the start.  That's the reason for my confusion...  That's why I'm wondering what the other factors could be.  I don't want to bring any possibilities up, at this point I think for obvious reasons.  I'm leaving the table open.
> 
> Plus, my question is more about the effect of more power going into an amplifier at this point, cable being less of a factor although there would still be that phenomenon to solve.  Plus, what you mentioned has been stated tens of times everywhere I looked which is the conclusion I come up with.  And yet, there are many people arguing for the opposite because of several other factors in play here.  The problem is that nothing is definitive.  For your statement to have validity, it would need to be followed with something along the lines of, "unless this and this and this and this.."  Etc...


 
  The law of physic is unfortunately not debatable. The other question you asked I have no answer to as you are stating IPAD sound different than FIIO. I do not know their design or have seen their spec. I can't really comment on it. I do not usually speculate on things.
   
  Power of course play a part in the sound but that will have no relationship to cable. If you have something more specific like FIIO and IPAD are using the xyz chip with mnp power supply. What is the difference? In my experience, my old CDman sound different than my new CDman and they sound different from my amps. That's because they are different design with different power supply.


----------



## Typhoon859

Quote: 





mikeaj said:


> Just an unimportant FYI, but FiiO E11 and most of their amps have bass boost options, but the flat setting is pretty flat.  E11 is within a 0.1 dB range from 20 Hz to 20 kHz.
> 
> I'd first suspect a DC blocking cap or otherwise output impedance issues with the iPad, and (as stated) the E11 is definitely more powerful.  Also, as usual, level matching is key.
> 
> ...


 

 Agreed.  I certainly understand that, even to the degree that you mention it.  I also understand that it's nothing personal, both things as was expressed here: "I'm just some random guy and nobody could really know to the extent to which I tested any of this". 
   
  About the E11, that's what I was trying to point out.  It's the one that is flat.  I mean.. I'll do a blind test (of course first having level matched), and I'll see if the differences are still identifiable as I claim.  I tried to be objective before this and I just didn't feel it was necessary since it was so profound.  It keeps coming back to this with everything, sigh...  I have a question for you .  At what point can I disregard these claims of doubt for x and y reasons?  Like right now, after doing this and supposedly spotting the differences.  What do I say to claims where an amp makes no difference past driving headphones/speakers louder than another amp?  This shouldn't be a forever long battle.  That's what I mean by when I say this back and forth between everyone is never ending.  Someone obviously has to be right and that should be established rather than, "figure it out for yourself; you do what you think is right and I'll do what I think is right, humph!"
   
  Quote: 





dvw said:


> The law of physic is unfortunately not debatable. The other question you asked I have no answer to as you are stating IPAD sound different than FIIO. I do not know their design or have seen their spec. I can't really comment on it. I do not usually speculate on things.
> 
> Power of course play a part in the sound but that will have no relationship to cable. If you have something more specific like FIIO and IPAD are using the xyz chip with mnp power supply. What is the difference? In my experience, my old CDman sound different than my new CDman and they sound different from my amps. That's because they are different design with different power supply.


 
  Never claimed the law of physics was debatable (although it technically is, just not in this case 
	

	
	
		
		

		
			





).  And what you're talking about is exactly the point here about, as you put it, IPAD vs. FIIO.  I don't see how me being more specific changes anything.  That also wasn't really a question but more a response to people claiming there isn't even a difference at the same levels between amps yet alone the same amp with more power being fed into it.  That's not to say that I believe that two correctly designed amps without compromises should sound any different.  What that of course entails is a proper DC current being fed into it depending on the volume for proper balance between the frequencies and of course at all levels not emphasizing, or rather, having enough and correctly distributed power for certain frequencies not to be emphasized over other.  Of course it's very vague by when I say "power" but the point is there.  What that furthermore entails I don't know and isn't largely relevant unless for the purposes of actually designing/engineering.


----------



## mikeaj

Quote: 





typhoon859 said:


> Agreed.  I certainly understand that, even to the degree that you mention it.  I also understand that it's nothing personal, both things as was expressed here: "I'm just some random guy and nobody could really know to the extent to which I tested any of this".
> 
> About the E11, that's what I was trying to point out.  It's the one that is flat.  I mean.. I'll do a blind test (of course first having level matched), and I'll see if the differences are still identifiable as I claim.  I tried to be objective before this and I just didn't feel it was necessary since it was so profound.  It keeps coming back to this with everything, sigh...  I have a question for you .  At what point can I disregard these claims of doubt for x and y reasons?  Like right now, after doing this and supposedly spotting the differences.  What do I say to claims where an amp makes no difference past driving headphones/speakers louder than another amp?  This shouldn't be a forever long battle.  That's what I mean by when I say this back and forth between everyone is never ending.  Someone obviously has to be right and that should be established rather than, "figure it out for yourself; you do what you think is right and I'll do what I think is right, humph!"


 
   
  I can't speak for everybody, but I think that most posters that would be lumped in the "amps sound the same" (given conditions...) camp would just say this:
   
  Amps that are similar in performance (driving a particular load) should sound similar.  The more similar the performance is, the more similar they should sound, until in some situations, you can't reliably distinguish the two by listening.  If they're even more similar than that, then they should be indistinguishable in every situation by listening.  As for how close you need to be, in what ways, and how to quantify those ways, people disagree about that.  
   
  Furthermore, consider that there are many different ways to achieve the same or similar results in many fields, including electronics.  Just because two amps have different designs doesn't mean that they must necessarily sound different when being operated under certain limits, especially considering that many are designed towards and ideal of not adding anything to the input given (so a "wire with gain").
   
   
   
  I would say it's very plausible and fairly likely that the iPad internal amp is compromised in enough ways that it would make some headphones sound different than on the E11, even after you level match, and even if you were to test it blind.
   
  If you don't want to prove anything, then just trust in whatever and be on your way.  
   
  But if you wanted to figure out why, I would suggest looking at the iPad's performance characteristics.  Start with the frequency response when driving the headphones you're using.  Even with some modest hardware, you can probably run the RMAA test signals out of the iPad (save the wavs and play them) connected to a splitter—one side to the headphones, the other side to a computer sound card to record.  If there's bass rolloff because of a DC blocking cap or some other impedance interactions, or just the FR is not flat in any scenario, you should see that.  If the FR is the same, then you have to start digging deeper.


----------



## dvw

Quote: 





typhoon859 said:


> Agreed.  I certainly understand that, even to the degree that you mention it.  I also understand that it's nothing personal, both things as was expressed here: "I'm just some random guy and nobody could really know to the extent to which I tested any of this".
> 
> About the E11, that's what I was trying to point out.  It's the one that is flat.  I mean.. I'll do a blind test (of course first level matched), and I'll see if the differences are identifiable.  It keeps coming back to this...  I have a question for you though.  At what point can I disregard these claims of doubt for x and y reasons?  Like right now, after doing this and supposedly spotting the differences.  What do I say to claims where an amp makes no difference past driving headphones/speakers louder than another amp?  That's what I mean by when I say this back and forth between everyone is never ending.  Someone obviously has to be right.
> 
> Never claimed the law of physics was debatable.  And what you're talking about is exactly the point here about, as you put it, IPAD vs. FIIO.  I don't see how me being more specific changes anything.


 
  Amps will not make a difference only if they are apple to apple comparison. For example, portable amps are different than desktop amp. And amps from different era are also different. I don't usually disclose what I own but for discussion purpose. I own (and still own) a Yamaha AV receiver, a Yamaha vintage receiver, a Nakmichi amp, a Nak receiver, Adcom amp, Bryston amp and a VTL amp. My wife said I am a hoarder. For headphones, it makes very different. But for speakers some makes a difference and some don't. It all depends on how easy it is to drive. My NHT/Hsu is very easy. There is practical no difference. On the other hand with my Maggies it makes a lot of difference because it is very power hungry. I like to think of amp as a power supply. If it can provide a little more than enough power, they should be no difference. Integrated device like IPOD and IPAD because of limited space and limited heat dissipation usually are limited in power supply. It is not just the average power but also the transient power. For example, My ADS (yes I have a lot of speakers too) is rated at 6 ohms, but at low frequency it will go to 2 ohms. An amp without high current capability or fast enough switching will make the music sound congested when there is a lot of bass content.
   
  IPAD and FIIO are two different animals. The comparison in this case should be instead two different USB cables going to the FIIO or IPAD vs a HP-PAD comparison. In this thread, ppl are thinking you're talking cable and not amp. Basically, all they're saying USB cable does not make a difference.


----------



## Typhoon859

Quote: 





mikeaj said:


> I can't speak for everybody, but I think that most posters that would be lumped in the "amps sound the same" (given conditions...) camp would just say this:
> 
> Amps that are similar in performance (driving a particular load) should sound similar.  The more similar the performance is, the more similar they should sound, until in some situations, you can't reliably distinguish the two by listening.  If they're even more similar than that, then they should be indistinguishable in every situation by listening.  As for how close you need to be, in what ways, and how to quantify those ways, people disagree about that.
> 
> ...


 
  Well let's start by saying that I didn't come into this thinking there was something THAT I WAS going to need to prove.  I came into this simply asking if more power by some specific means into an amp can have an effect on the sound.  That's generally put.  As for further details, I didn't realize that something like a "better amp" NOT designed similarly or with the "correct result" even in mind I would have to prove makes a difference.  I came here for those on a similar track to explain what things may factor into my original question(s) and possibly why.
   
  I'm not sure how I'm supposed to prove this apart from the way I mentioned which I WOULD BE willing to do.  I could've easily lied and said that I did ABX testing considering how convinced I was but in the end that's just counter productive and generally stupid.  Instead I tried to be honest and at least make clear that I am very much aware to the fullest of extent of all the kind of problems which may impede judgment. 
   
  Plus, the iPad was just an example.  I mean, this is the case with any Apple PMP or other product which has line-out capabilities as a platform to be able to compare.  I'd guess it would also apply to any other players, especially where that's not a focus, unless it's like the iBasso or something.  Plus, the kind of testing you're talking about A) I'm sure should be out there, if not, that just contributes to another point I was making.  B) It's inherently flawed because there is too much data which factors into sound to be able to determine differences or lack thereof with only one factor.  As testing means in cases like this (not when designing your own thing), it's more effective to do controlled listening trials with different people, or actually, trained acousticians and/or audio engineers.  Am I supposed to do that?  I haven't met a person that hasn't said I have good ears, including musicians and other long-time audio engineers.  In general I can distinguish some pretty great things.  The point is just that, under the right conditions, if I notice SIGNIFICANT changes then that should be enough to go by.  All that remains is trust and preconditioned disbelief.  I'm not saying that's the particular case here as of yet but just in general. 
   
  What people often forget is that not always does such a claim discredit their own beliefs and/or understandings.  Often times it simply means there's another factor here at play which wasn't in play with your particular testing/findings.  Many headphones for instance have some level of compression, whether it's soundstage, dynamics, or frequency.  So, even with headphones known to be quite good like the Sony MDR-V7506's in terms of neutral frequency response, you might've not come across the differences.  With neutral and "uncompressed" headphones in pretty much every regard like the Brainwavz HM5's, differences may become apparent.  More transparency in other words...  Even after the amplification stage, before it gets to your ears, not everything that goes in is what comes out.  That's true for all preceding stages before it as well, and the point again I guess is that there are often many overlooked factors.
   
  Quote: 





dvw said:


> Amps will not make a difference only if they are apple to apple comparison. For example, portable amps are different than desktop amp. And amps from different era are also different. I don't usually disclose what I own but for discussion purpose. I own (and still own) a Yamaha AV receiver, a Yamaha vintage receiver, a Nakmichi amp, a Nak receiver, Adcom amp, Bryston amp and a VTL amp. My wife said I am a hoarder. For headphones, it makes very different. But for speakers some makes a difference and some don't. It all depends on how easy it is to drive. My NHT/Hsu is very easy. There is practical no difference. On the other hand with my Maggies it makes a lot of difference because it is very power hungry. I like to think of amp as a power supply. If it can provide a little more than enough power, they should be no difference. Integrated device like IPOD and IPAD because of limited space and limited heat dissipation usually are limited in power supply. It is not just the average power but also the transient power. For example, My ADS (yes I have a lot of speakers too) is rated at 6 ohms, but at low frequency it will go to 2 ohms. An amp without high current capability or fast enough switching will make the music sound congested when there is a lot of bass content.
> 
> IPAD and FIIO are two different animals. The comparison in this case should be instead two different USB cables going to the FIIO or IPAD vs a HP-PAD comparison. In this thread, ppl are thinking you're talking cable and not amp. Basically, all they're saying USB cable does not make a difference.


 
  There we go, exactly.  So then more specific to this thread, what would then need to be figured out is the problem of why certain cables would for instance charge my phone while others wouldn't, from the same source assuming there's "nothing wrong" with them. 
   
  But again, this whole comparing amps thing is a side-track.  Going full circle back to the initial phrasing of my question with the cable part of it for now excluded, could more power through a USB powered amp such as the FiiO E10 result in a "fuller" sound?  Presence and dynamics in lows and mids, possibly as a result of transient power?  You started going in the right direction there in terms of what I think is relevant to note, although maybe only for the case of comparing one amp to another for a particular set of cans/speakers.


----------



## ultrabike

@Typhon859:
   
  When you heard differences when using your FiiO vs you iPad, did you use the same USB cable?
  Did you hear a difference in your FiiO (or iPad) when using different USB cables?
   
  I'm not very familiar with the iPad, can it supply power through a USB adapter, or does the adapter gets it's power independently?


----------



## Typhoon859

Quote: 





ultrabike said:


> @Typhon859:
> 
> When you heard differences when using your FiiO vs you iPad, did you use the same USB cable?
> Did you hear a difference in your FiiO (or iPad) when using different USB cables?
> ...


 
  It gets its power independently.  In this comparison a USB/power cable was not involved.  It was just an example for the purposes of making a point against that one amp vs. another doesn't make a difference in most cases in quality for low impedance headphones/speakers, as this related to the question of whether more power to a USB powered amp provides more "quality", and as that furthermore related to whether a cable could make a difference in that regard or not. 
   
  I mentioned a simple case where I thought the difference between two amplification units was clearly evident.  I thought just giving that example would be enough but obviously I was mistaken.  I thought it was a shared understanding that a dedicated amp such as the one mentioned vs. any portable players of the likes results in noticeable improvement.  I've been convinced to the point where I feel this may not be true but it remains to be seen.  It would be crazy if I imagined that much of a difference, and so specific too.  I will do blind testing for it.


----------



## ultrabike

Quote: 





typhoon859 said:


> It gets its power independently.  In this comparison a USB/power cable was not involved.  It was just an example for the purposes of making a point against that one amp vs. another doesn't make a difference in most cases in quality for low impedance headphones/speakers.  I mentioned a simple case where it clearly did.  I thought just giving that example would be enough but obviously I was mistaken.  I just thought it was a shared understanding that a dedicated amp such as the one mentioned vs. any portable players of the likes results in noticeable improvement.  I've been convinced to the point that this may not be true but it remains to be seen.  I will do blind testing for it.


 
   
  I think Amps make a difference. Probably not as much as the headphones themselves, but they do IMO. Cables? Probably less so.
   
  To compare cables, I would definitively keep everything else the same for comparison purposes, and I would make sure that sufficient power is available. I think power loss through the cable shouldn't be an issue if the source has sufficient headroom to cover it along with the Amp needs.


----------



## mikeaj

E11 is just a $60 portable amp, no DAC.
   
  When there is enough volume, you're more likely to find differences between amps by listening when using *lower* impedance headphones, not higher.
   
  DACs getting power through USB is different than amps getting power.  Amps just draw as much power from the source as they use, where power consumed comes in the form of losses throughout the electronics as well as power delivered to the headphones.  I think there's some handshaking involved between USB host and slave between what power draw is acceptable.  There are some proprietary charging mechanisms using USB plugs.  I think some phones may not charge from some devices that don't actually communicate over the data lines—others are fine with a device that's just giving it the +5V and ground.  I'm not sure if any are sensing the USB +5V level.  If you have a USB cable that is (non-defective) but relatively long and thin, maybe you'll get enough of a voltage drop across the line to mess some devices up, especially combined with a host device that's drooping on the +5V level?  That sounds a bit farfetched but not impossible.


----------



## Typhoon859

Quote: 





mikeaj said:


> E11 is just a $60 portable amp, no DAC.
> 
> When there is enough volume, you're more likely to find differences between amps by listening when using *lower* impedance headphones, not higher.
> 
> DACs getting power through USB is different than amps getting power.  Amps just draw as much power from the source as they use, where power consumed comes in the form of losses throughout the electronics as well as power delivered to the headphones.  I think there's some handshaking involved between USB host and slave between what power draw is acceptable.  There are some proprietary charging mechanisms using USB plugs.  I think some phones may not charge from some devices that don't actually communicate over the data lines—others are fine with a device that's just giving it the +5V and ground.  I'm not sure if any are sensing the USB +5V level.  If you have a USB cable that is (non-defective) but relatively long and thin, maybe you'll get enough of a voltage drop across the line to mess some devices up, especially combined with a host device that's drooping on the +5V level?  That sounds a bit farfetched but not impossible.


 

 It does sound farfetched.  It's what I was thinking but also why I didn't mention it. 
   
  In regards to the whole DAC vs. Amp thing.  Again, simply based on the understanding of their functions, I assumed the same.  As I said in my very first post, with USB as the source, some indicated elsewhere that the FiiO E17 (which has a battery) is dependent on the power from the USB regardless (which is confusing since it has an S/PDIF input as well).  But in any case, that's why I resorted to using the FiiO E10 as an example just for the sake of getting to the bottom of this in general, before it gets more specific. 
   
  In any case, what do you say to my previous response?  What would you think of the results I'd come back with after having done a proper blind test.  Keep in mind that the unbiased result is just as important to me if not more so.  In other words, would this test on my part be sufficient enough for you?  The point would be for all amps alike, not just some possible flaw with the iPad's.


----------



## TickleMeElmo

Quote: 





ultrabike said:


> I think Amps make a difference. Probably not as much as the headphones themselves, but they do IMO. Cables? Probably less so.
> 
> To compare cables, I would definitively keep everything else the same for comparison purposes, and I would make sure that sufficient power is available. I think power loss through the cable shouldn't be an issue if the source has sufficient headroom to cover it along with the Amp needs.


 
   
  The problem with analog signal is much more difficult to quantify. I can see things like ambient air pressure, air temperature, humidity, how clean your ears are on a given day, your blood pressure at a specific time, position of the headphones on your head, etc to all make a bigger difference than a silver cable and a copper cable. When you start analyzing minutiae like audio cables you would need not only ABX testing on an individual but ABX testing on a significant sample size of individuals to make any kind of statistically relevant judgement. The only real definitive judgement that can be made is on USB transfers since there is a specific protocol and a boolean "right," and "wrong," rather than the infinite shades of gray of analog.


----------



## Lorspeaker

....and the time u listen to yor music...dinner time and midnite...a world of difference in my apartment.
  the ambient noise level...and visual cues....lighting level....all add/detract from my enjoyment.
   
  yes and that braided colored usb cable...once i pluggggg it in....heaven rolled into my living room..
  its as scientific as that.


----------



## ultrabike

Quote: 





typhoon859 said:


> In any case, what do you say to my previous response?


 
   
  My answers in blue (assuming you are asking about your original questions/comments.) Hope this helps 
	

	
	
		
		

		
		
	


	



   
  Quote: 





typhoon859 said:


> Maybe I missed it but there is something that's not being addressed which I would like to inquire about.
> 
> I've been reading things here and there about USB because of many strange things I've experienced in the past - details like *phones not charging with some but charging with others, strange inconsistencies with different sources of power supply with different cables*,
> 
> ...


 
   
  If things were kosher and you still heard differences between two standard USB cables... Then do tell what cables u used! (do not drink whisky while performing your test though)


----------



## Typhoon859

Well thank you.  That was nice to see a response to my original post.  I appreciate it, sincerely.
   
  I was actually talking to *Mikeaj* though about a previous response I made to him about something different but nonetheless... 
   
   
  "*Some USB cables are defective and non-standard compliant.*"
  As has already been suggested to which I have replied, I really doubt it could be such a large quantity.  Plus, I would be hard pressed to believe that the differences can be to such varying degrees.  For instance, I could take a USB cable and plug it into my device from one source; it works.  I could take it to another and it doesn't.  The I could do the same test with another cable and it works in both places.  You could make a point that falls in line with this notion of non-standard compliance and/or them being defective in some way.  What I mentioned though is just one example and it gets even more jumbled with more sources, more cables, more devices - such tests. 
   
*Even if this were 100% the issue, it means that USB cables DO VARY, WHATEVER THAT REASON MAY BE.  The question isn't whether correctly made/standard USB cables could make a difference over another correctly made/standard cable.  The question is if any one USB cable THAT WORKS could make a difference?  Even in the example I gave, it clearly means one cable is providing more power than the other.  I don't know how to quantify that but here we are again at the start.  Just saying...*
   
  "*You need power hubs because the source may not be able to provide enough power. I can tell you that I tried all of my USB cables to try to power my USB 500G drive from my NAS and it did not work. Used a Hub with ANY USB cable and presto! You can get an active (powered) long USB cable from monoprice BTW. Thickness my solve the issue for long haul, but it may not be very practical.*"
  It's not just dependent on the source past certain distances.  For reasons I forget, it states on USB.org that due to the nature of the design of USB, there is power leakage that occurs.  I don't know how or why scientifically but that's what was said.  I had a really good article/page about many things where it was broken down but I found something kind of relevant which just would suggest the idea that there's more involved in the transmission of the signal than there would be say a power/audio cable.  http://www.ehow.com/about_5365028_maximum-length-usb-cable.html
   
  "*The S/PDIF and USB interfaces usually are separate circuits and perform differently due to their different implementations... There are more differences than just power drawn.*"
  Right, I understand that, but I meant like in terms of just the power which would be at the DAC stage.  I meant that contrary to what was mentioned about the difference between e.g. and Optical connection and USB, I thought the DAC was powered the same - with the battery, since there is no power source when connected one way vs. the other.  As I think I mentioned, I thought the USB cable (power wise) just served as a function for charging the battery, not a direct source of power. 
   
  "*It does if it cannot supply enough power to the device. Usually an Amp that sources it's power from USB should be designed with the USB interface standard in mind. It would be flawed to design a 500W USB powered monoblock.*"
  Right, obviously, but I meant in cases where IT IS enough either way but still different in the amount transmitted. 
   
  "If things were kosher and you still heard differences between two standard USB cables... Then do tell what cables u used!"
  I never did this test as it's way to prone to placebo.  That's why I came here after searching, assuming there was possibly a well established answer SPECIFICALLY TO THIS and not just to theories which people apply. 
   
   
  And uh, thanks again for the response.


----------



## liamstrain

Quote: 





typhoon859 said:


> *The question is if any one USB cable THAT WORKS could make a difference?  Even in the example I gave, it clearly means one cable is providing more power than the other. *


 
   
  That is not the only conclusion to draw from that situation... it could just as easily be a slight variation in the connector's pin layout that isn't within the tolerances of a given device.


----------



## Typhoon859

Quote: 





liamstrain said:


> That is not the only conclusion to draw from that situation... it could just as easily be a slight variation in the connector's pin layout that isn't within the tolerances of a given device.


 

 Hmm, well I dunno...  If the scenario I mentioned is replicable with another device then that wouldn't be it.  Plus, I always tried to align the connection in every way possible when it didn't work in the circumstances that it was a case of bad contact.


----------



## bigshot

typhoon859 said:


> About the E11, that's what I was trying to point out.  It's the one that is flat.




The iPad has a stone flat frequency response through line out.


----------



## bigshot

ultrabike said:


> I think Amps make a difference.




i've found that amps that are old or underpowered can sound different. But modern solid state amps that are performing to spec all sound the same at normal listening volumes.


----------



## Typhoon859

Quote: 





bigshot said:


> The iPad has a stone flat frequency response through line out.


 
  Right, through the line out - why it sounds better through an external amp vs. its internal.
  Quote: 





bigshot said:


> i've found that amps that are old or underpowered can sound different. But modern solid state amps that are performing to spec all sound the same at normal listening volumes.


 
  As would make sense.


----------



## bigshot

typhoon859 said:


> Right, through the line out - why it sounds better through an external amp vs. its internal.




The iPad, iPhone and iPod are designed to be portable devices. The headphone out is tweaked to work best with the impedence of small, portable headphones to preserve battery life on the go. If you try to listen through the headphone jack using full size studio headphones, it's not going to be able to push it. That's when you dock it and run through the line out. Through line out, the sound quality of the iPad is as good as a standalone home CD player. It doesn't matter what cable you use.


----------



## ultrabike

Quote: 





bigshot said:


> The iPad, iPhone and iPod are designed to be portable devices. The headphone out is tweaked to work best with the impedence of small, portable headphones to preserve battery life on the go. If you try to listen through the headphone jack using full size studio headphones, it's not going to be able to push it. That's when you dock it and run through the line out. Through line out, the sound quality of the iPad is as good as a standalone home CD player. It doesn't matter what cable you use.


 
   
  That's my understanding. Here is an interesting article regarding headphone impedance and amps:
   
http://www.innerfidelity.com/content/comparison-beyerdynamic-dt-880-32-ohm-dt-880-250-ohm-and-dt-880-600-ohm-headphones
   
  Among other things, the headphone impedance should be 10x the Amp impedance to minimize interactions that would result in colored sound.
   
  @ Typhoon859: What headphones and DAC/AMP do you use?


----------



## ultrabike

Quote: 





> Originally Posted by *Typhoon859* /img/forum/go_quote.gif
> 
> The question is if any one USB cable THAT WORKS could make a difference?  Even in the example I gave, it clearly means one cable is providing more power than the other.  I don't know how to quantify that but here we are again at the start.  Just saying...
> 
> ...


----------



## bigshot

The cable issue really isn't an issue except with commissioned stereo salesmen and internet "know-not-quite-enoughs". Most audio professionals and experienced hi-fi nuts know the score.


----------



## ultrabike

Audiophile cables may be one of those products that if you have or haven't tried, either way you won't know what you are missing.


----------



## joeyjojo

As long as recording studios continue to use normal, cheap, cables to record the music I'm listening to, I won't be investing in anything more expensive.
   
  "Cable enthusiasts" are welcome to indulge their habit just like anyone else, but they shouldn't encourage others who aren't adept at critical thinking.


----------



## liamstrain

To be fair, some studios do use expensive cabling. What is unclear is what drives most the specific decisions. The majority of the engineers I have worked with are very adamant about balanced wiring for long cable runs (makes sense) but they could care less who makes the wires (or what material). They are worried about the physical and measurable factors... not the woo woo. 
   
  But there are a few outliers out there that have bothered with some of the more esoteric cable blends - sometimes driven by a belief that if offers a real benefit, sometimes for the bragging rights of saying they are using X-brand cabling as part of their marketing, sometimes because the cable makers have provided the cable so that they can claim X-studio uses theirs exclusively.
   
  It's a weird world we live in.


----------



## bigshot

I've worked with a bunch of great sound houses in Hollywood. I actually asked a couple of Head Engineers what they used. They buy great big giant spools that they get at the pro audio supply equivalent of monoprice.

The few that use high end cables have a licensing agreement and fee for their name to be used in marketing I'd wager.


----------



## drez

I'm sure some of them drink the koolaid.  To be honest though I don't see why they would use USB in preference to Firewire if the equipment supports it (apart from the cables using more conductors and therefore costing more...)
   
  Some audio production people are pretty deep into the digital tweaks - they probably have not done blind testing but honestly some differences do not warrant it such as newly soldered cables sound way too warm and smooth at the start, but IMO this is some sort of distortion.  Either way I am sure anyone could hear this, only problem is you need to mock up a new USB cable each time you want to test this, and this will probably vary depending which factors contribute to this initial warmth.  Also how would you control the variables, each cable would need to be tested empirically etc. it's a bit of a long shot.  Would be interesting to look into anyway if I have time to terminate some factory produced cable I have my eye on.  I wonder how much of the "wow this cable sounds so different" is due to some sort of similar effect with new cabling...
   
  This initial performance may or may not be indicative that the cable is operating within USB spec, and this is difficult to prove unless one has an oscilloscope to test DIY cables for characteristic impedance.  If this were to occur on something like a monoprice that might be different but from what I have seen they are fairly sensible with the solder connections.  I would not recommend their round SATA cables though - they made my computer unstable - maybe not as tight control over the impedance as the flat SATA cables.  They look quite a mess inside in terms of the geometry, shielding drain wires etc.  SATA of course is operating at a much larger frequency range, and yes generally most cables that are within spec will work.  I might need to do some benchmarks to see if there are any differences that can be verified (and maybe get me my $2.50 per cable back lol
	

	
	
		
		

		
			





).  I did recheck that cables were seated properly but in the end I needed to put the flat cables back in to bring the system stability back to normal.
   
  An intersting case study might be CAT5/6 as these also share 100 Ohm characteristic impedance, but no doubt over a much lower frequnecy range than SATA, also designed to be used in a much lower noise environment etc.  Actually a few buotique labels jumped on the  network cable market, but I wonder how they stack up against a standard CAT6 cable, or how these would supposedly make a difference unless they are being used as I2S interconnects...  I would hate to think how much 15 meters would cost 
	

	
	
		
		

		
		
	


	




  As I mentioned earlier I think the fact that many boutique cables are sold in such short lengths is a way of cheating with the performance.
   
  On the pro-audio cable  thing though a colleague of mine said that he compared some unnamed buotique coax cables and they performed worse than Belden, I think he commented that the boutique brand actually performed badly...  Having said this I don't think it is logical to deduce from this that all boutique digital cables are rubbish, just that they are an unknown quantity as they do not publish specs.  They are quite a big risk because of this as well as the fact that what people consider to sound "better" is not always better performance in my experience.  The pro-audio cabling with published specs and proper engineering is a much more prudent investment, and no doubt this is why many studios use these brands.  People are right to be suspicious anyhow.
   
  What is perhaps more damning though is that some companies publish specs for some cables and not for others, or publish some specs but not anything as extensive those published by Belden etc.  One does wonder what they have to hide.  Maybe people like the sound of poor measured performance, maybe the specs are just pretty ordinary?  It's hard to say until somebody measures these things properly.


----------



## bigshot

When it comes to cables, none of the engineers I spoke with cared about sound. They only cared about durability. They wanted to know that if they spent a few weeks wiring a mixing board, it wasn't going to short out anytime soon.


----------



## liamstrain

Quote: 





bigshot said:


> When it comes to cables, none of the engineers I spoke with cared about sound. They only cared about durability. They wanted to know that if they spent a few weeks wiring a mixing board, it wasn't going to short out anytime soon.


 
   
  +1000
   
  With the exception of susceptibility to EFI noise or crosstalk over long runs, etc.


----------



## dvw

Quote: 





drez said:


> I'm sure some of them drink the koolaid.  To be honest though I don't see why they would use USB in preference to Firewire if the equipment supports it (apart from the cables using more conductors and therefore costing more...)
> 
> Some audio production people are pretty deep into the digital tweaks - they probably have not done blind testing but honestly some differences do not warrant it such as newly soldered cables sound way too warm and smooth at the start, but IMO this is some sort of distortion.  Either way I am sure anyone could hear this, only problem is you need to mock up a new USB cable each time you want to test this, and this will probably vary depending which factors contribute to this initial warmth.  Also how would you control the variables, each cable would need to be tested empirically etc. it's a bit of a long shot.  Would be interesting to look into anyway if I have time to terminate some factory produced cable I have my eye on.  I wonder how much of the "wow this cable sounds so different" is due to some sort of similar effect with new cabling...
> 
> ...


 
  Well; I used to work in the standard body that decide the spec. The deciding factors are EMI, BER, distance and cost. CAT5/6 cables needed to be backward compatible that's why they're 100 ohms. They also need to be 100 meters in length. This is why there is a difference in length and speed between protocol. This has nothing to do with cable quality but more with law of physic and what can be achieved at a reasonable cost. I will challenge any body that can make a USB cable to go 100 meters. Boutique cable will not have better performance than a standard compliant cable.
   
  Imagine this, if indeed cable can enhance or degrade quality of music, people will be complaining about the music they bought. Bittorrent will no longer exist. There will be audio grade phone wire and audio grade DSL services. Why would a source music downloaded from 30/40 year old skinny phone wire sound better through a boutique USB cable?


----------



## JadeEast

To be fair the phone wire had 30 or 40 years of  burn-in.


----------



## grokit

Downloading a music file just depends on overall error correction, it isn't quality-dependent on timing accuracy and electrical noise isolation like playback of that file can be. So the debate goes anyways.


----------



## dvw

Quote: 





grokit said:


> Downloading a music file just depends on overall error correction, it isn't quality-dependent on timing accuracy and electrical noise isolation like playback of that file can be. So the debate goes anyways.


 
  yes. But how does timing accuracy affect better bass, more detail and better sound stage. How is timing affected by USB cable? Let's assume, there is a 1 ns jitter. Does this mean USB 1.1 performs better than USB3 because percentage is lower? Let's further assume the clock is derived from the USB. How is that related to the recording clock? I mean assuming the sampling clock is 44KHz +/- 1 KHz. My recording clock is 43KHz. How does the USB send out this clock? If I am sending one track after another, one has a 43KHz clock and another has a 45KHz clock. Does the USB clock actually change? How does this impact the other devices on the bus? 
   
  Personally I don't think the same argument on SPDIF works with USB.


----------



## bigshot

Wouldn't minute timing errors affect high frequencies where the waveform is all bunched up, than low frequencies where the waveform is five feet long?


----------



## dvw

The only timing error came from the jitter when you have too much coffee. The sound stage seems smaller when you're pacing on it. This is not the right time to measure the sound stage.


----------



## drez

Quote: 





dvw said:


> yes. But how does timing accuracy affect better bass, more detail and better sound stage. How is timing affected by USB cable? Let's assume, there is a 1 ns jitter. Does this mean USB 1.1 performs better than USB3 because percentage is lower? Let's further assume the clock is derived from the USB. How is that related to the recording clock? I mean assuming the sampling clock is 44KHz +/- 1 KHz. My recording clock is 43KHz. How does the USB send out this clock? If I am sending one track after another, one has a 43KHz clock and another has a 45KHz clock. Does the USB clock actually change? How does this impact the other devices on the bus?
> 
> Personally I don't think the same argument on SPDIF works with USB.


 
   
  I'm not sure but I think HiFace describe the transfer mode they use as bulk mode, although I'm not sure how this applies specifically and it probably varies depending on the driver in question.  This is an interesting question though as it does throw into question a lot of the assumptions regarding how USB cables might affect jitter in USB audio.  I can say that my personal non-controlled experience with the battery modified HiFace I was using that USB cabling (especially length with very short cables eg <10cm) did still affect the sound for better or worse, and that was completely powered from battery, and presumably doesn't care much about the timing of incoming data as it uses batch mode with some sort of hardware buffer.  It would be interesting to find out how many samples are sent in each USB transfer packet, but I have my doubts that the driver designers will be willing to disclose this information.  Are there any open source USB audio driver projects??
	

	
	
		
		

		
		
	


	




.  Knowing what I know now though, maybe too short cabling may have made signal reflections worse but I guess it is hard to say without testing.


----------



## AKG240mkII

Quote: 





drez said:


> This is an interesting question though as it does throw into question a lot of the assumptions regarding how USB cables might affect jitter in USB audio.


 
  I say it's YOU throwing in 'an interesting question' ..
   
  Either the '0' and '1's are there .. Or they are not .
  IF the 'cable' complies with standards and has no mechanical defects it will transfer all the 0 and 1's .
  If not, the receiving end will know .
  (There is a slight possibility of ground-loop issues in some cases, this could easily be audible)
   
  It's not alchemy, it's computer-'science' .


----------



## liamstrain

bigshot said:


> Wouldn't minute timing errors affect high frequencies where the waveform is all bunched up, than low frequencies where the waveform is five feet long?


 
   
  No. The number of bits for a high frequency or low frequency are the same (1s and 0s) for any given segment of time.


----------



## BlackstoneJD

I bought the Transparent USB cable to cover all my bases. I never did a real comparison. It was an inexpensive tweak. I also like the styling and build quality. I love their stuff so I figured why not for $95.


----------



## Clarkmc2

blackstonejd said:


> I bought the Transparent USB cable to cover all my bases. I never did a real comparison. It was an inexpensive tweak. I also like the styling and build quality. I love their stuff so I figured why not for $95.



Not as much as some, but way too much for what it is supposed to do.


----------



## dvw

Quote: 





drez said:


> I'm not sure but I think HiFace describe the transfer mode they use as bulk mode, although I'm not sure how this applies specifically and it probably varies depending on the driver in question.  This is an interesting question though as it does throw into question a lot of the assumptions regarding how USB cables might affect jitter in USB audio.  I can say that my personal non-controlled experience with the battery modified HiFace I was using that USB cabling (especially length with very short cables eg <10cm) did still affect the sound for better or worse, and that was completely powered from battery, and presumably doesn't care much about the timing of incoming data as it uses batch mode with some sort of hardware buffer.  It would be interesting to find out how many samples are sent in each USB transfer packet, but I have my doubts that the driver designers will be willing to disclose this information.  Are there any open source USB audio driver projects??
> 
> 
> 
> ...


 
  The USB transfer modes are not proprietary and can be downloaded through the USB forum web site. The drivers are chip specific and are usually provided by the chip vendor for free. 
   
   For cable, as long as the cable are compliant, they should work just fine. Bit error cause the audio to have a pop corn like sound. It sounds like a lot of static. The poor quality you hear on your cell is caused by bit error (the phone will try to compensate for it). If you hear a lot of static then you have a transmission issue. You will not lose bass or treble because of bit error.


----------



## drez

Quote: 





akg240mkii said:


> I say it's YOU throwing in 'an interesting question' ..
> 
> Either the '0' and '1's are there .. Or they are not .
> IF the 'cable' complies with standards and has no mechanical defects it will transfer all the 0 and 1's .
> ...


 
   
  Welcome to Head-Fi - I see you have taken the obligatory 1's and 0's pamphlet to heart.  Now  that I have grasped this I have been able to fully resolve a theory of quantum gravity and at the same time solved world hunger.
	

	
	
		
		

		
		
	


	




  Seriously sorry just I have heard that argument about a million times and don't find it cute anymore
	

	
	
		
		

		
		
	


	



   
  In fact what I was saying is that some of the assumptions about how timing variations from the computer or cable may be far from what is happening given what *dvw* was saying about the clock frequency of USB it may not be possible for USB to send individual samples over USB and is instead probably sending a certain number of samples at a time in bulk mode.  My guess is that asynchronous just makes it easier for the USB audio device to manage the buffer.
   
  Most decent USB transports now include galvanic isolation, but otherwise if you are running a desktop PC you could just use the same earth for your DAC and the computer.  If you are running a laptop then galvanic isolation might be necessary as the laptop uses a floating ground.  I don't think this is directly related to most USB cable sound difference claims.
   
  Under normal circumstances I don't think USB transports drop packets as long as they have well designed drivers and a large enough buffer on the computer side.  Most of what I have been discussing is trying to figure out what is causing some of the observable differences between computer hardware and software that I have and continue to observe derive from given that there is little scientific explanation beyond simply writing off these observations as invalid or flawed/unreliable.  I personally find it highly unlikely that suggestion and cognitive bias is responsible for repeated and independent observations of variations between hardware and software including cables, playback software etc.  Unfortunately philosophical and financial factors have generally thwarted attempts to make progress in establishing a scientific understanding of computer based music transports.
   
  For USB cables I think the influence may be how little they can add noise and jitter to the digital signal pair, power and ground connections.  Why do I think this might affect audio quality - mostly because USB was not designed to handle real-time multimedia interfaces like Firewire, PCI etc.  This may be a tenuous argument but if you look at the Firewire and USB standards they are very different in both hardware and software.  USB audio now uses asynchronous transfer but I am not sure that this magically fixes the limitations of using USB for audio in the same way that buffers do not magically fix any timing variations that originate upstream no matter what the manufacturers claim.  
   
  As to why software might make a difference the most convincing arguments I have heard are from the makers of Puremusic for Mac and JPlay for PC - they claim that by using different driver level changes they can achieve more consistent latency, and that this, even with asynchronous transports, can lead to better sound quality.  Who knows, maybe the latency is not directly having an influence but instead it is affecting electrical noise and voltage stability of the USB connection, nobody has really shown a causal link between any of these factors and sound quality.  From my own observations though these factors can be heard with most equipment quite easily.  If you cant hear a difference or don't believe me that's fine, maybe your gear has better jitter immunity or something but for me it is worthwhile to pursue these things as I do hear differences, and I would suggest that they are at least worth investigating if not investing in


----------



## bigshot

Welcome to Sound Science. Just saying you can hear it and coming up with a complicated explanation of what you think you might be hearing don't cut the mustard here.

Have you done controlled testing to verify what you think you hear?
How much noise and jitter? Have you measured it?
What is the threshold of audibility for this kind of noise and jitter?

And the bonus question... What does this noise and jitter sound like?


----------



## Currawong

You can read a great deal from industry experts who have done the measurements and tests here:
   
  http://www.head-fi.org/t/493152/low-jitter-usb-dan-lavry-michael-goodman-adaptive-asynchronous
   
  Short answer is, USB Audio is a streaming protocol where timing (and thus waveform quality) matters a great deal, unlike the digital transmissions inside a computer.  However newer electronics that buffer the stream (are asynchronous) or otherwise reduce the jitter significantly before conversion make USB quality _mostly_ a non-issue.
   
  There is one member here who has the $100k of equipment necessary to test down the femtosecond level of jitter, as well as other things whom, if asked kindly, might consent to doing some measurements, so that instead of arguing based on beliefs, you can argue over your beliefs in the relevance of some measurements instead.


----------



## grokit

Oh yeah, latency.
  I forgot about that one


----------



## drez

Quote: 





bigshot said:


> Welcome to Sound Science. Just saying you can hear it and coming up with a complicated explanation of what you think you might be hearing don't cut the mustard here.
> Have you done controlled testing to verify what you think you hear?
> How much noise and jitter? Have you measured it?
> What is the threshold of audibility for this kind of noise and jitter?
> And the bonus question... What does this noise and jitter sound like?


 
   
  Haha touche
	

	
	
		
		

		
		
	


	



   
  Controlled testing with USB cabling would require a second person willing to humor my interests which is not something I can arrange easily at present.  I may be able to do so in the future but this would be rather a kind (or unkind) gesture toward sound science.  Contrary to popular belief I am not here to prove anything, and doing so would in my opinion be a disservice as some people with some systems simply do not hear some of these changes (software and differences in transports).
  I am not making any specific claims about jitter.  playback software developers such as XXHighEnd and CPlay have attempted to measure the jitter performance of their respective projects but given the history of this thread I would not attempt to offer this as evidence of better performance.  Again it would be a theory to explain what I claim to hear between different softwares, and again these variations are easy for anyone to verify of their own accord and I would encourage them to do so.
  I have no clue as to the specific threshold of audibility of noise and jitter in an SPDIF transport, if one were to measure the level of electrical noise on the SPDIF output of the Audiophilleo 2 and compare this to the new battery powered version I would offer this as a possible demonstration.  Again I have not blind tested the difference between these (I have done a sighted comparison switching between the two at a recent meet but did not have time to compare blind) but if anyone is interested I would encourage them to compare between the two at their own leisure.
  I do not know what jitter sounds like, and further I am not sure what aspects of the differences I am hearing is attributed to jitter or not.  This kind of study is beyond the resources and knowledge I have at my disposal.
   
  If I were to return to a conversation we had a while ago - I do not consider my casual observations to be evidence upon which other people should make decisions, but for my own decision making I consider them to be adequate as even if the differences are imagined, they are real to me.


----------



## liamstrain

Quote: 





currawong said:


> You can read a great deal from industry experts who have done the measurements and tests here:
> 
> http://www.head-fi.org/t/493152/low-jitter-usb-dan-lavry-michael-goodman-adaptive-asynchronous
> 
> Short answer is, USB Audio is a streaming protocol where timing (and thus waveform quality) matters a great deal, unlike the digital transmissions inside a computer.  However newer electronics that buffer the stream (are asynchronous) or otherwise reduce the jitter significantly before conversion make USB quality _mostly_ a non-issue.


 
   
  It is also ABUNDANTLY clear, that the difference of a USB cable cannot affect just the bass, or just the treble energy, or any such claims.
   
  And as regards jitter or latency and such, as far as I know, all streaming USB protocols (adaptive, sync, or async) have electronics in place which deal with jitter and other timing issues *before* the D/A Conversion - the only place that it would even possibly matter.


----------



## drez

Quote: 





liamstrain said:


> It is also ABUNDANTLY clear, that the difference of a USB cable cannot affect just the bass, or just the treble energy, or any such claims.
> 
> And as regards jitter or latency and such, as far as I know, all streaming USB protocols (adaptive, sync, or async) have electronics in place which deal with jitter and other timing issues *before* the D/A Conversion - the only place that it would even possibly matter.


 
   
  That is if we are assuming the cable can only have an effect through jitter, which is probably true if the SPDIF output is galvanically isolated and run from an independant power supply.
   
  In my casual, sighted experience I have heard a USB controller contribute artifical bass bloom and heft, as well as changes is processor scheduling, different HiFace drivers could all effect the degree of bass and lower midrange bloom, of course none of these are USB cables so I have probably digressed but these are easier elements to isolate as they have definite functions that can be identified.
   
  Not that it matters really but I think much of what is considered to be the sound of jitter is rubbish and being mistaken with other influences (maybe electrical noise, or just even just more accurate reproduction etc.)  This interview with Igor Levin tends to suggest that the relationship between jitter and sound signature is not so straightforward:


----------



## Currawong

Quote: 





liamstrain said:


> Quote:
> 
> 
> 
> ...


 
   
  What is lacking here in these discussions are specifics. I've seen this posted, in effect, numerous times, but no discussion or specifics about individual DACs and their capabilities. I also posted those links so that people who are interested in genuinely learning, not just arguing, might do some research. Beyond that, I'm not making any specific argument, just trying to direct the discussion to something beyond the regular arguments which don't benefit anyone.
	

	
	
		
		

		
		
	


	



   
  As I asked, is anyone interested in some actual measurements and experiments or only interested in arguing what they believe is correct?


----------



## liamstrain

currawong said:


> As I asked, is anyone interested in some actual measurements and experiments or only interested in arguing what they believe is correct?


 
   
  I would be interested to see actual measurements. Both timing issues/jitter and the usual run of frequency response comparisons would be interesting to see.


----------



## bigshot

Lots of specifics in the first post of this thread....

http://www.head-fi.org/t/486598/testing-audiophile-claims-and-myths

This really is the most useful post in Sound Science. It really should be pinned at the top of the forum. Maybe you could do that for us, Currawong.


----------



## dvw

Quote: 





currawong said:


> What is lacking here in these discussions are specifics. I've seen this posted, in effect, numerous times, but no discussion or specifics about individual DACs and their capabilities. I also posted those links so that people who are interested in genuinely learning, not just arguing, might do some research. Beyond that, I'm not making any specific argument, just trying to direct the discussion to something beyond the regular arguments which don't benefit anyone.
> 
> 
> 
> ...


 
  What measurement are we talking about here? Jitter of the cable or jitter of the USB port. I do not disagree jitter has a effect on sound quality (in measurement). I do disagree that an exotic silver USB cable will fix it. And I am not sure how much people can actually precieve jitter. I am an engineer. The engineering approach to this is first to identify the problem.
   
  1. What does jitter sound like? I have seen any description of what jitter sounds like other than the cable sounds better, has more bass, has more detail. And we know it can not be true as cable can not modify 1 and 0 in a non-random manner.
  2. If indeed, we found jitter is observable through normal listening. The jitter can be from the transmitter, cable or receiver. We can now try to identify the source of jitter. The jitter in the cable could be in fs and not even ps. From my experience, the jitter are sourced mostly from the transmit driver and not the cable.


----------



## bigshot

Jitter in the levels it occurs in even the least expensive audio gear does not affect sound quality. Not audible.


----------



## Currawong

dvw: Did you read Dan Lavry's posts? He wrote about the effects specifically.  I don't think "jitter has a sound", I think his point was that jitter can degrade the sound, but how much or how noticeably doesn't have simple figure of X picoseconds or X nanoseconds but is complex and depends on many factors.
   
  Specifically regarding USB cables, manufacturers I have spoken to suggested that they need to have the correct characteristic impedance (just as any digital cable should). My feeling at the moment is, having played around with a bunch of combinations of cables, components and other things, is that they should be as short as possible as well, but that could be because the longer cables I've used all passed by other equipment and may have been picking up noise.
   
  I really do wish I could test all of this, as I think it would be good to try and get some useful information that can be helpful to people, so I'll see if that can't be done. Just don't hold your breath, as I've got a bunch of other things I want to do as well.


----------



## estreeter

Quote: 





bigshot said:


> Jitter in the levels it occurs in even the least expensive audio gear does not affect sound quality. Not audible.


 
   
  Strongly disagree, but I can see how this could quickly degenerate so I'll leave it there,


----------



## mikeaj

Quote: 





bigshot said:


> Jitter in the levels it occurs in even the least expensive audio gear does not affect sound quality. Not audible.


 
   
  I don't have any sources to cite or evidence, but I wouldn't be so sure of that, particularly if you phrase it as "audio gear."  Maybe we're thinking of different things?  Are you thinking on the level of cheap CD players, iDevices, etc.?  Or anything like a computer, phone, whatever would be used for music playback?  How about really junky integrated audio systems for those cards that play recorded messages, a GPS device, whatever?
   
  But anyhow, I think the point is that nobody yet seems to have proved jitter audibility at levels close to that of modern low-end dedicated consumer playback gear.  That said, isn't it hard to adjust the amount of jitter at very low levels for testing?  It's not like you can compare device A with device B, since they will differ in a lot of other ways other than jitter.  Anyway, I won't discount a possibility, but it's not something I think is probably a big deal, given the levels we're talking about.  Then again, most audiophiles don't tend to care about things in the correct order of importance, so latching onto jitter doesn't seem like a surprise, regardless of the actual importance...
   
   


currawong said:


> dvw: Did you read Dan Lavry's posts? He wrote about the effects specifically.  I don't think "jitter has a sound", I think his point was that jitter can degrade the sound, but how much or how noticeably doesn't have simple figure of X picoseconds or X nanoseconds but is complex and depends on many factors.
> 
> Specifically regarding USB cables, manufacturers I have spoken to suggested that they need to have the correct characteristic impedance (just as any digital cable should). My feeling at the moment is, having played around with a bunch of combinations of cables, components and other things, is that they should be as short as possible as well, but that could be because the longer cables I've used all passed by other equipment and may have been picking up noise.
> 
> I really do wish I could test all of this, as I think it would be good to try and get some useful information that can be helpful to people, so I'll see if that can't be done. Just don't hold your breath, as I've got a bunch of other things I want to do as well.


 
   
   
  The most important message from Dan Lavry and Michael Goodman (and what many people have been saying all along) is that jitter matters at the D/A conversion.  It doesn't matter what happens elsewhere as long as the jitter at the conversion is low enough.  This point seems to be ignored by many.
   
  It's up to the D/A device designer to deal with whatever input signal comes in.  For all but the cheapest USB DAC implementations, I really don't see any substantive relationship between the jitter on the USB data transmission that the USB receiver chip sees and any jitter at the output of the DAC chip.
   
  Or is everybody buying expensive USB cables for their $20 USB DAC that uses one of those low-end all-in-one USB receiver/DAC chips (one that actually uses its integrated DAC) that makes no attempt at cleaning anything up, getting better sound quality?  And even then, is it an audible concern?  Even if it's an audible concern, don't you have bigger issues to worry about with a $20 DAC?
   
  That's even supposing it really matters, that for some reason you're focusing on the cable rather than the USB host and of course the device on the receiving end, that the differences between cheap and expensive cables (which ones?) really amount to something much.
   
  I mean, hopefully people buy expensive DACs before expensive USB cables, and the expensive DACs already took care of the issue.  Oh wait, we're trusting audiophile gear to take care of anything properly, aren't we?


----------



## bigshot

We're talking about cd players and things to listen to music on. Why would I be talking about anything else?

I think we owe it to newbies to speak clearly and not go into supefluous detail. A lot of times people are so busy outlining the exceptions to the rule they give the impression that the baby has been thrown out with the bathwater. I can't think of a reason why we need to spend any more time discussing jitter except to say it's a non issue. That's the fact that we need to get across to newbies.


----------



## mikeaj

Quote: 





bigshot said:


> We're talking about cd players and things to listen to music on. Why would I be talking about anything else?


 
   
  Dunno, just throwing stuff out.  I'm sure there are some extremely suspect audio devices used to listen to music that nobody's bothered to measure, but I think that's besides the main point since nobody worrying about these things is using their laptop (and I mean one of the worst laptops for audio, not something with relatively good integrated audio.  or what's worse than that?  some old phones?) directly as the source.


----------



## grokit

Quote: 





currawong said:


> Specifically regarding USB cables, manufacturers I have spoken to suggested that they need to have the correct characteristic impedance (just as any digital cable should). My feeling at the moment is, having played around with a bunch of combinations of cables, components and other things, is that they should be as short as possible as well, but that could be because the longer cables I've used all passed by other equipment and may have been picking up noise.


 
   
  Definitely +1 on the impedance issue. I have a usb to spdif converter with an aes/ebu output, and I tried to listen to it using a slightly better than average 3-pin XLR audio cable to connect that to my DAC's input. It was nothing you would want to listen to for too long. Then I got a digital cable with the correct impedance and everything was hunky-dory.
   
  It does get mentioned from time to time that too short of a coax or usb cable can degenerate the signal as well. I have a 6" Belkin on the way to connect to a simple usb to spdif converter, we'll see if it's detrimental.


----------



## drez

I think the possible issue with short cables is signal reflections, I think the idea with longer cables or ferrites is to attenuate the reflections/noise within the cable.  Like anything though this all depends on specifics so one would need to use an oscilloscope to study the cable to determine how much of a problem signal reflections are.  Signal reflections to my knowledge are caused by stray impedances, so this will probably vary with cable termination, connector type, in there is a hookup used inside the divice etc.


----------



## estreeter

I can't wait to hear NAD's C390DD (the M2 is well above my budget) - taking the analog conversion completely out of the equation is an interesting prospect. Ironically, anyone needing to hook an analog source up to one of these amps now has to buy an optional MDC module. Ditch the DAC for an ADC and look forward to DSP updates further down the pike.Outstanding.


----------



## dvw

Quote: 





currawong said:


> dvw: Did you read Dan Lavry's posts? He wrote about the effects specifically.  I don't think "jitter has a sound", I think his point was that jitter can degrade the sound, but how much or how noticeably doesn't have simple figure of X picoseconds or X nanoseconds but is complex and depends on many factors.
> 
> Specifically regarding USB cables, manufacturers I have spoken to suggested that they need to have the correct characteristic impedance (just as any digital cable should). My feeling at the moment is, having played around with a bunch of combinations of cables, components and other things, is that they should be as short as possible as well, but that could be because the longer cables I've used all passed by other equipment and may have been picking up noise.
> 
> I really do wish I could test all of this, as I think it would be good to try and get some useful information that can be helpful to people, so I'll see if that can't be done. Just don't hold your breath, as I've got a bunch of other things I want to do as well.


 
  To be honest, I did not read Dan's paper in great depth because I did not find any new and insightful information. Not that I disrespect Dan, but I have been in the communication business for 20 years and jitter is a major issue for us to deal with. I am not a jitter expert but I know quite a few that are. The major difference between our work are in communication we're dealing with Kms of cables that often do not have great continuity. Meaning cables might be 24AWG for 500 meters and then 28AWG for the next 1.5 Km. So how much magic jitter can there be in 1 meter of USB cable. IMO, the majority of jitter is contributed by the PLL and not the cable. Here's an example paper. http://www.kenkundert.com/docs/aacd97.pdf This is a little too much for this forum.
   
  My issue with the explanation that jitter in the cable are:
  1. Description of the sound of jitter. I am not dealing with people's ability to hear jitter yet. No one has given a qualitative description of jitter. Degradation of audio is not a description. More bass/more treble is not a description. Jitter actually modulated the signal. For example, if you play an off center LP, part of the playing will be at a higher speed than the other part, this change the frequency of the signal. This is not an  accurate analogy of jitter but it is simple to use without getting into Fourier Transform.
  2. Second issue I have is nobody has explained to me how is the play clock derived from the USB clock (source of jitter right?). If a recording is done with a 44.1KHz +/- 1 KHz clock, How does the USB know it is 43KHz and not 45KHz? What if there are two tracks streaming and one with 43KHz and one with 45KHz?
  3. Let's ignore the difference in USB2.0 and 3.0 with regards to synchronizing them to the play clock. The jitter will be smaller in relation to the clock period of a slow USB than a fast USB. Does this mean you have better performance in USB1.1 than USB2.0? Why hasn't any DAC been touting that fact?
   
  I think there are just so much disinformation out there to justify the extraordinary price of these cables. We just need to drill down on it. I'm surprised nobody is selling an ionizer to make the air more conductive so we get more detail when we're streaming music over WiFi.


----------



## dvw

Quote: 





drez said:


> I think the possible issue with short cables is signal reflections, I think the idea with longer cables or ferrites is to attenuate the reflections/noise within the cable.  Like anything though this all depends on specifics so one would need to use an oscilloscope to study the cable to determine how much of a problem signal reflections are.  Signal reflections to my knowledge are caused by stray impedances, so this will probably vary with cable termination, connector type, in there is a hookup used inside the divice etc.


 
  It's easier to damp the reflection with a small serial resistor. The drawback is you will be attenuating the signal. Too long a cable might have round trip delay issue.


----------



## liamstrain

dvw said:


> Jitter actually modulated the signal. For example, if you play an off center LP, part of the playing will be at a higher speed than the other part, this change the frequency of the signal. This is not an  accurate analogy of jitter but it is simple to use without getting into Fourier Transform.


 
   
  And that begins to make sense for analogue audio signals. But not for digital. That would only cause a skew in the timing between the bits, but not their values (which would determine the frequencies) and the timing would - presumbably, be fixed in any re-clocking the transfer does.


----------



## dvw

Quote: 





liamstrain said:


> And that begins to make sense for analogue audio signals. But not for digital. That would only cause a skew in the timing between the bits, but not their values (which would determine the frequencies) and the timing would - presumbably, be fixed in any re-clocking the transfer does.


 
  You are correct and that's why I stated it is not accurate Someone else has called me out on it before. Jitter does skew the timing and it does it by a certain frequency as well. The drift in timing goes back and forth. This is known as the jitter frequency. Without the back and forth action it will be just a drift in frequency (replay is simply slowed/speeded down). This jitter has a frequency and this frequency modulated the signal and generate two other frequencies. So in a way, instead of harmonic distortion it is a frequency distortion. I am not very good in explaining this. Someone else could give this a better shot, please do.
   
  I used the off center LP as an analogy because as the turntable turns, the distant side (relative to the hole) will have a higher velocity and produce a higher pitch. The less distant side will have a lower pitch. As you point out this is not the same as digital timing skew, but I think it's good enough for simple understanding. Sorry for dumbing it down. But this is the best I can come up with.
   
  What exactly does jitter sound like? I am not sure because I really never heard an identified jitter induced sound. But this is what I think it could sound like. If jitter is severe, it will miss bits and this will sound like a lot of pop. If the jitter frequency is high, it might be beyond human hearing. If it is low then, it could sound like a change in pitch. Of course, this is assuming, the jitter is large and uncorrected.


----------



## bigshot

Jitter would affect higher frequencies first, I would imagine.


----------



## dvw

Jitter affects frequency across the board. In communication that I worked on, the voice band is limited to 3.5KHz. But since we have to pass this signal through miles of cable (digital), jitter becomes a big issue. In today's technology, packet loss and latency become a bigger issue. Interesting thing is people are so used to poor voice quality of cell phone. No one has complained about the reduced quality. This is what I mean by our ears are getting burned in.


----------



## mikeaj

dvw said:


> My issue with the explanation that jitter in the cable are:
> 1. Description of the sound of jitter. I am not dealing with people's ability to hear jitter yet. No one has given a qualitative description of jitter. Degradation of audio is not a description. More bass/more treble is not a description. Jitter actually modulated the signal. For example, if you play an off center LP, part of the playing will be at a higher speed than the other part, this change the frequency of the signal. This is not an  accurate analogy of jitter but it is simple to use without getting into Fourier Transform.


 
   
   
  It's a timing error (or frequency modulation, if you want to think of it that way... in the frequency domain, you get some sidebands and spread of the original frequency).  At 44.1 kHz sampling rate, you're supposed to more or less get a new sample (of course it's not an abrupt occurrence, because of the nature of the filtering and reconstruction) every 22.6757 [size=small]µ[/size]s or so.  Let's call that amount the time unit.  A 441 Hz tone should be 100 time units per period.  With jitter, it might be 100.001 samples per time unit, or 99.999 samples per time unit.  Or sometimes 100.002 or 999.998 samples, or less frequently 100.0008 or 99.9992 samples?  I guess this should sound like some kind of flutter / warble / vibrato effect.
   
   
   


dvw said:


> 2. Second issue I have is nobody has explained to me how is the play clock derived from the USB clock (source of jitter right?). If a recording is done with a 44.1KHz +/- 1 KHz clock, How does the USB know it is 43KHz and not 45KHz? What if there are two tracks streaming and one with 43KHz and one with 45KHz?


 
   
  By "play clock" you mean the timing of the DAC's output?  If the recording was done with a jittery ADC process, then the recording should be compromised (audibly so, if somehow at a high enough level) because information was not sampled at the correct times.  That has nothing to do with any USB transmission later on.  I'm not sure what you mean by two tracks streaming at different frequencies.  In one audio signal chain, there's only going to be one track, and its average frequency is going to be 44.1 kHz (48 kHz, 96 kHz, etc.).


----------



## dvw

Quote: 





mikeaj said:


> It's a timing error (or frequency modulation, if you want to think of it that way... in the frequency domain, you get some sidebands and spread of the original frequency).  At 44.1 kHz sampling rate, you're supposed to more or less get a new sample (of course it's not an abrupt occurrence, because of the nature of the filtering and reconstruction) every 22.6757 [size=small]µ[/size]s or so.  Let's call that amount the time unit.  A 441 Hz tone should be 100 time units per period.  With jitter, it might be 100.001 samples per time unit, or 99.999 samples per time unit.  Or sometimes 100.002 or 999.998 samples, or less frequently 100.0008 or 99.9992 samples?  I guess this should sound like some kind of flutter / warble / vibrato effect.
> 
> That's a better articulation.
> 
> ...


 
  By play clock, I mean the sampling rate that you're playing the recording with. Let's say the recording is done with a sampling rate of 44.1 KHz with a tolerance of 1 KHz. So it is recorded with 43KHz. And you derive the clock from the USB and get a sampling rate (play clock) at 45KHz. You will have a buffer underflow and the file is virtually unplayable. If you have a file recorded at 43 KHz and another at 45KHz, how do you play them back to back from the derived clock from USB. Now if you say USB transmission has nothing to do with it. Then the jitter from the USB transmission has nothing to do with the playback at the DAC.
   
  This is a long winding way of saying jitter at the USB does not affect play back. Only the jitter at the DAC clock matter.


----------



## grokit

Quote: 





estreeter said:


> I can't wait to hear NAD's C390DD (the M2 is well above my budget) - taking the analog conversion completely out of the equation is an interesting prospect. Ironically, anyone needing to hook an analog source up to one of these amps now has to buy an optional MDC module. Ditch the DAC for an ADC and look forward to DSP updates further down the pike.Outstanding.


 
   
  Kind of like a USB cable direct to the power amp, kudos to NAD for shaking things up.
   
   

   
   

   
   
  It had better be one bad@ss USB cable though


----------



## estreeter

grokit, I'm assuming you have read Darko's conclusion to his C390DD review ? Joining 6Moons seems to have endowed him with a touch of Srajan's legendary loqaciousness. but he gets there in the end. I get where he is coming from with the 'Power DAC' terminology. but its a misnomer for the NAD amps as your diagram clearly illustrates. 
   
As a one-box solution NAD’s C390DD seals all the magic under one roof, where DAC and amplifier play as conjoined twins. There are no interconnects to ruin the party or blow out the budget. If resolution and transparency are your top priorities, NAD’s ‘power DAC’ could have you starting again (seriously). With Class D, there will always be those that espouse the ruling classes (A and A/B) without apriori listening. To those unencumbered by such dogma, I say this: if your current DAC and amp ran you close to $3k in pursuit of a diffident neutrality, give serious though to selling them and buying this. Yes, for real.


----------



## grokit

Yes the only problem with the integrated setup is the same as all integrated components when compared to their separated counterparts. If one section fails or you want to change your sound, all of your eggs are mounted to the same chassis.


----------



## bigshot

Receivers used to have jumpers in the back connecting their preamp circuitry to their power amp circuitry, so you could patch in at the last stage to equalize or do whatever you wanted to everything all in one spot. I haven't seen those lately. It's a drag. They probably dropped that feature because of multichannel sound.

There really isn't a tape loop with optical or HDMI. I don't think my Yamaha will allow you to map the output of the HDMI out and then back in. How do you patch in a 5:1 equalizer? I guess you'd need an external HDMI or optical switcher of some sort. That would be an ugly kludge.


----------



## Clarkmc2

Back in the day I seem to remember a lot of pre outs, but few if any amp ins.


----------



## estreeter

Quote: 





grokit said:


> Yes the only problem with the integrated setup is the same as all integrated components when compared to their separated counterparts. If one section fails or you want to change your sound, all of your eggs are mounted to the same chassis.


 
   
  The NAD amps gp beyond that - unless you want to buy one of the analog modules, you may as well throw any tube pre-amp (or CDP with a tube output stage) you own in the closet - even with said module, your lovely analog signal will be digitised before it hits the power amp in the NAD. It really is an 'all or nothing' choice', but how many SET amps offer you the potential to upgrade the sound with nothing more than a firmware upgrade ?


----------



## bigshot

clarkmc2 said:


> Back in the day I seem to remember a lot of pre outs, but few if any amp ins.




It was a pair of U shaped metal bars on the back. I never knew what they were for until a friend showed me.


----------



## dvw

Quote: 





grokit said:


> Kind of like a USB cable direct to the power amp, kudos to NAD for shaking things up.
> 
> 
> 
> ...


 
  With this configuration, they should have an WiFi option with a source selection menu. With that you can stream sound through out the house from your servers, PC, iPOD.


----------



## TickleMeElmo

*Announcement:*
   
  I think we have missed the forest for the trees. USB cables are the problem, the USB *controller* is the problem, I have heard the the Intel PCH controller is much better than any of the ASMedia chips, you should check your controller and make sure you have your $300 USB cable connected to the correct controller.


----------



## Griploc

Do you think it beats an apogee symphony io interface? Thats my dac


----------



## Currawong

Bigshot: I used to have a Luxman amp with those. I think it may still be possible with their current series, but you have to enable it via a switch.
   
  TickleMeElmo: Some audiophile types buy special USB cards for computers they are using for dedicated playback. Other than that, I've always been of the mind that it simpler to build a PC using Intel boards as the likelihood of issues with chips and drivers are minimised, but I'm not that experienced in building PCs. I do recall some of the early USB and USB 2.0 controllers being absolutely awful.


----------



## Grev

I'm actually really interested in that NAD thing now, provided that I have a few of the NAD amps already.


----------



## TickleMeElmo

Quote: 





currawong said:


> Bigshot: I used to have a Luxman amp with those. I think it may still be possible with their current series, but you have to enable it via a switch.
> 
> TickleMeElmo: Some audiophile types buy special USB cards for computers they are using for dedicated playback. Other than that, I've always been of the mind that it simpler to build a PC using Intel boards as the likelihood of issues with chips and drivers are minimised, but I'm not that experienced in building PCs. I do recall some of the early USB and USB 2.0 controllers being absolutely awful.


 
   
  I was being facetious. That said the native USB plug nearest to your PCH controller (thus minimizing the length of the trace) will theoretically offer the best performance and the least steps through different logic. Some motherboards do have issues when you plug too many USB devices in.
   
  If you are using a USB card for a computer (not sure they are even made anymore since most desktops have ten or more USB devices), it's probably going to be PCI-E these days, which means it will probably be going through the PCH lanes, onto another piece of silicon for the USB controller.


----------



## drez

Quote: 





ticklemeelmo said:


> I was being facetious. That said the native USB plug nearest to your PCH controller (thus minimizing the length of the trace) will theoretically offer the best performance and the least steps through different logic. Some motherboards do have issues when you plug too many USB devices in.
> 
> If you are using a USB card for a computer (not sure they are even made anymore since most desktops have ten or more USB devices), it's probably going to be PCI-E these days, which means it will probably be going through the PCH lanes, onto another piece of silicon for the USB controller.


 
   
  I have embarrassingly tried one of the audiophile USB controllers and it sounded crap - I have since come to a similar conclusion that the more direct connection from the USB controllers on the motherboard chipset, and USB port with shortest signal path are in theory the best.  Mini-ITX might cut out another 10 cm of motherboard trace but I doubt the difference will be significant.  Then again maybe more signal reflections so who knows.  I think most people fail to appreciate the downsides to various noise removal techniques.  In the end USB uses differential signalling after all.


----------



## estreeter

Quote: 





dvw said:


> With this configuration, they should have an WiFi option with a source selection menu. With that you can stream sound through out the house from your servers, PC, iPOD.


 
   
  A digital receiver ? Not sure why NAD would build that into a product which already dispenses with the requirement for a separate DAC. particularly when they also sell a dedicated streamer :
   
http://www.theabsolutesound.com/articles/nad-c-446-digital-media-tuner-tas-223/
   
   
 _The $800 NAD C 446 is, indeed, an FM/AM tuner, but as part of its mission as a Digital Media Tuner it also gives you access to the near-infinite world of Internet radio, plus the ability to stream a music library from network storage devices, and most significantly to wirelessly stream from a computer, Android phone, Apple iOS device, or network hard-drive using Universal Plug-and-Play (UPnP). As is the norm today, wireless streaming is limited to conventional 16-bit/44.1kHz resolution._

 _The C 446 offers support for many popular digital formats including wav , aac +, and flac , and outputs them via its 24-bit/192kHz DAC. Other features include the ability to digitize FM/AM for output as S/PDIF and a front-panel USB input for thumb-drive playback. The C446 also supports cloud music services so that you can access your music library from multiple devices. Adding NAD’s optional IPD 2 Dock permits iPod/iPhone docking/charging via a back-panel input. About the only thing the C 446 doesn’t have is a USB DAC—even a company as resourceful as NAD has budgets to meet after all. But don’t fret; NAD wasn’t napping. NAD has several USB-DAC solutions that can always be added down the road. Even so, the C 446 is a veritable digital crock-pot for music delivery._

   
  project86 started a very interesting thread on streamers, and reviewed a couple of the newer offerings, but it didn't get the level of interest I thought it would. He makes the point in that thread that this is a market segment that is evolving rapidly - NAD and its competitors are better served with dedicated streamers, IMO. 
   
  If you still want an all-in-one that does streaming. Naim's SuperUniti gets solid reviews but costs considerably more than the C390DD.


----------



## Currawong

Streaming is almost definitely the way to go I reckon. It took me a while, but I "get" why Linn and others are big on it. It seems to remove all the issues with using a computer as a transport. I was using my iPad this way, since it can stream up to 24/96 using the Camera Connection Kit and I was happy with the results.
   
  I wonder if streaming servers can power USB devices. I imagine not.


----------



## estreeter

The Marantz and CA streamers have onboard DACs and USB-B connections for same, but AFAIK none of the streamers have support for connection to a USB-only DAC, but the purpose-built music servers are way out of my budgetary sights. Chris Connaker has a very high opinion of the Aurender S10, but at *over 8 times* the sticker price of the Marantz NA7004 DAC/streamer, I have a sneaking suspicion that they wont get the same slice of  this market. Interesting times.


----------



## drez

I think more often than not streaming servers just have linux boxes hidden inside, albeit really stripped back linux install with realtime bios or something.  There are a couple of companies that sell dedicate music server computers which basically do exactly this.  If someone did an open source linux distro that could do the same thing you could replicate one of these music server son a $50 Raspberry Pi or some similar minimalist computer.  Or you could use a squeezebox, or even an Ipad as you say or another similar portable music player may be plausible.  I've seen a box that streams wave files from SD cards which might be useful if you find all your music on SD cards for some reason.
   
  I don't think computer transports are completely flawed, they are quite powerful devices just unfortunately with an excess of functionality which sometimes gets in the way of reliable, high quality audio streaming.  Personally I prefer to have the hard drive withing the music server for my own audiophool reasons, as well as my rather biased mistrust of wireless networks.  I guess I am a compulsive tinker so the promise of improved performance spurs me on [to misadventure.]  I also don't think a thousand dollar USB cable is going to magically transform your computer based music setup - its only a cable after all and it can only do so much, for better or worse.  I do find things that continue to surprise me with computer based music, both good and bad (I've been burned a few times now by recommendations of others unfortunately.)


----------



## bigshot

My music server is Mac Mini based. It's pretty much plug and play and the sound is all you could wish for. I stream music 24/7 throughout my house using Airports. The same server drives my hidef projection system. Everything patched using HDMI.. I'm extremely happy with it. Very dependable, even though it's been running all the time for two years.


----------



## IPodPJ

currawong said:


> Streaming is almost definitely the way to go I reckon. It took me a while, but I "get" why Linn and others are big on it. It seems to remove all the issues with using a computer as a transport. I was using my iPad this way, since it can stream up to 24/96 using the Camera Connection Kit and I was happy with the results.
> 
> I wonder if streaming servers can power USB devices. I imagine not.




This is why I use a Logitech Transporter (highly modified with toroidal trafos, two Audio-gd clocks, Audio-gd power supply, all caps replaced, DAC section severed, analog outputs severed) solely as a streamer to generate the S/PDIF signal feeding the Ref 7.1. It is the best sounding solution I've found, and takes the computer out of the computer. The nice thing about the Transporter is that there is ample empty space inside the unit to put these extras.

They don't sell the original Transporter anymore because apparently they couldn't get anymore tactile feedback knobs, so they put a plastic plug in its place and now sell it as the Transporter SE for several hundred less. You use the remote in place of the knob. With the original version like I have you can use either. Granted the black plastic plug isn't very pretty but the performance should be identical to the original. And for those who don't already have a DAC the internal one is still quite good, but not in the same league as the Ref 7.1.

I can control the entire system using iPeng on my iPhone and iPad, or you can use the Squeezebox controller app for iPhone but it is not as good as iPeng. When using the computer though, you have to use the Squeezebox Server software which, while it works fine, isn't as pretty or easy to use as iTunes – it's only downside.


----------



## estreeter

Amazon has eight Transporters left from 1180 USD, but that would I'm guessing the mods you've got on your Transporter would add a significant lump of cash to that sticker price.
   
  . http://www.amazon.com/gp/offer-listing/B0011YZ1R6/ref=dp_olp_new?ie=UTF8&condition=new
   
  RIP Squeezebox.


----------



## dvw

I guess there is no open source/control software available to put in a single remote control device like an Ipod..
   
  I can stream with just window from one PC to another. I also stream from my Ipod with a creative giztmo. I also used a media player. But this is like have three different remote with a terrible UI. If only I can integrate all these player with an unified UI instead  of walking around with my portable 1TB HDD.


----------



## bigshot

I use a Harmony link in my theater. It is a IR to wifi converter so I can use my iphone to run everything. Works like buttah!


----------



## BlackbeardBen

DLNA


----------



## IPodPJ

estreeter said:


> Amazon has eight Transporters left from 1180 USD, but that would I'm guessing the mods you've got on your Transporter would add a significant lump of cash to that sticker price.
> 
> . http://www.amazon.com/gp/offer-listing/B0011YZ1R6/ref=dp_olp_new?ie=UTF8&condition=new
> 
> ...




Those are the Transporter SE I was talking about, not the original Transporter. Still good prices though, and sonically is the same unit. Surprisingly my mods weren't as much as you might think, but the cost to repair damage caused by a Power Plant Premier added to it.


----------



## Sandman65

purrin said:


> Because any dielectric will polarize the electrons. Essentially the cable becomes a capacitor.
> 
> The EMI theory however is more sound. I actually got a subtle, but notable improvement by wrapping my USB cable with aluminum foil.




I find wearing the foil on my head makes everything sound so much better!


----------



## Citan

lulz


----------



## WeLikeAudio

Quote: 





proton007 said:


> A similar thread got locked just yesterday. Whats the point of this one?


 
  +1


----------



## estreeter

Any chance you two could take that up with a moderator instead of thread-crapping ? Some of us have actually posted info pertinent to computer-based audio and USB connections specifically - we ARE in Sound Science and we aren't derailing anyone's discussion of a specific component. If you want the thread locked, there are people who can do that - personally, I think you would be throwing the baby out with the bathwater.


----------



## Grev

I want the NADs.


----------



## ultrabike

Quote: 





blackbeardben said:


> DLNA


 
   
  I like NFS a little better myself


----------



## ultrabike

Quote: 





dvw said:


> Well; I used to work in the standard body that decide the spec. The deciding factors are EMI, BER, distance and cost. CAT5/6 cables needed to be backward compatible that's why they're 100 ohms. They also need to be 100 meters in length. This is why there is a difference in length and speed between protocol. This has nothing to do with cable quality but more with law of physic and what can be achieved at a reasonable cost. I will challenge any body that can make a USB cable to go 100 meters. Boutique cable will not have better performance than a standard compliant cable.
> 
> Imagine this, if indeed cable can enhance or degrade quality of music, people will be complaining about the music they bought. Bittorrent will no longer exist. There will be audio grade phone wire and audio grade DSL services. Why would a source music downloaded from 30/40 year old skinny phone wire sound better through a boutique USB cable?


 
   
  You worked on the 10GBase-T standard dude?


----------



## dvw

Quote: 





ultrabike said:


> You worked on the 10GBase-T standard dude?


 
  Yes I did in the beginning. But in theory 10G (over 100 meters) was not possible. We then have a bunch of startup with a bunch of PhDs that joined. The proposal was way too much for my tiny brain. So we have to bring in the big guns, and I dropped out.


----------



## ultrabike

Quote: 





dvw said:


> Yes I did in the beginning. But in theory 10G (over 100 meters) was not possible. We then have a bunch of startup with a bunch of PhDs that joined. The proposal was way too much for my tiny brain. So we have to bring in the big guns, and I dropped out.


 
  LOL! I was one of the dudes that brought up the first link (AFAIK) over 100 meters with CAT-6 with BER < 10e-12 (was both Systems/FW engineer on a startup.) It's a small world!


----------



## dvw

looking at your location, you must be working at the S company. I used to work for the B company. I am now officially retired. It is a small world indeed. Knowing my background, surely you understand where I am coming from.


----------



## ultrabike

Quote: 





dvw said:


> looking at your location, you must be working at the S company. I used to work for the B company. I am now officially retired. It is a small world indeed. Knowing my background, surely you understand where I am coming from.


 

 Yup, I used to work for the S company, which got split and it is now part of the M company


----------



## LFF

Quote: 





ultrabike said:


> Yup, I used to work for the S company, which got split and it is now part of the M company


 

 Never knew that!
   
  In another life, I would have liked to be part of Easy Company.


----------



## ultrabike

Quote: 





lff said:


> Never knew that!
> 
> In another life, I would have liked to be part of Easy Company.


 
   
  LOL!!!


----------



## Griploc

Ok, i have finally recieved the usb endorphin cable from stefan audio art. Iwill be doing a dbt at the end of the week on saturday, i will put up a pic of the cable tonight once i am home


----------



## gattari

II was very skeptical about audible differences in usb cable.
 But having experienced only by mere curiosity with some usb cable and my ODAC, now I am sure that there are differences and  sometimes differences are large enough to think that I have not changed a cable but a source ).
Yes Yes Yes cable made difference.
  Of course, if the system I have is poor and ill-sounding, I can change all the cables I want without results.


----------



## liamstrain

Thank you for your testimony. Did you do blind tests, or any sort of abx to determine that the changes you heard were due to the cable?


----------



## ultrabike

Quote: 





gattari said:


> II was very skeptical about audible differences in usb cable.
> But having experienced only by mere curiosity with some usb cable and my ODAC, now I am sure that there are differences and  sometimes differences are large enough to think that I have not changed a cable but a source ).
> Yes Yes Yes cable made difference.
> Of course, if the system I have is poor and ill-sounding, I can change all the cables I want without results.


 

 What cables did you use? ... And what Amp + Headphones did you use?


----------



## gattari

I use sennheiser hd 800 and odac + o2amp.
I had more expensive amp and sell it now. 
I don't have expensive usb cable, but I have a lot of usb cable and tested it. 
The synergy concept is basilari to set up good sounding system. 
Actually with odac + o2amp + hd 800 I have the best synergy with a Sony top camera usb cable with ferrite near odac input. 
The sound of hd 800, anyway very good, now is magic to my ears. 
But if I put a low impedance headphone in this system I have bad. bad sound. 
This is my subjective experience.
Any system is different, but try different usb cable don't cost nothing. and you could be a surprise rear the corner. 
I don't need abx test to know that Sony usb cable is the best. It is clearly the best in that particolar contest. 


Pardon my English. 



Inviato dal mio GT-I9300 con Tapatalk 2


----------



## ultrabike

Thanks... And how are the usb cables affecting the sound: signal drop outs, hissing, better cleaner bass, more tremble detail? In other words, can you describe what aspect of the sound is being changed with the usb cables you have so far tried?


----------



## gattari

In my case the response on upper high frequency are changed, more rounded, and at same time detailed not anymore little harsh, but in general the music was more enjoyable to listen to. 
I am very happy for result, I repeated the test and the result was the same, Sony cable was clearly the winner. 


Inviato dal mio GT-I9300 con Tapatalk 2


----------



## ultrabike

I have several *USB cables*, and can't say I have *ever* experienced a change in the high frequencies. I have experienced audio drop outs due to poor contacts, but that's about it... at least with my equipment, and it seems you have some pretty decent equipment yourself.
   
  Have you done some blind tests? Also, It is possible to perceive audio different if your brain/ear has acclimated to your headphones (the HD800 has been described by some as relatively bright...)


----------



## bigshot

A faulty digital cable can't create an overall coloration to the sound. There has to be some other cause.


----------



## drez

If any USB cable is going to affect SQ a ferrite like that on a camera cable is probably a much more significant differnce than between typical construction USB cables.  How it may or may not do so, or whether it does or not is a matter of speculation, and based on the technical understanding of the technology and research in the area one would not expect any effects between perfect function and audio dropouts.
   
  I have my own theories about how a USB cable *might* affect the actual sound reproduction, but as I am not an expert in the field this will probably not be all that useful to everyone.  If we were to look at what a ferrite might do to the USB signal, it would have an influence over signal propagation and risetime, the magnitude of these differences on their own would be pretty small and as previously discussed individual samples cannot possibly be sent at the requisite sampling frequency so a number of samples must be sent in a single transfer packet, which makes it even more difficult to predict that there should be an audible influence over the music playback.  The ferrite *might* also be suppressing noise on the digital signal and +5V lines - the noise *shouldn't* be an issue as the USB tranfer uses differential signalling which should effectively reject common mode noise.  My guess is the only way a USB cable could possible affect audio playback is by affecting the hardware buffer being used on the USB DAC/transport.  Whether or not one accepts this hypothesis would depend on whether or not one believes that buffer size can affect USB audio.  In my own experiments I think that I can detect a difference between massive changes in buffer size in the playback software eg. 0.05 seconds compared to 1.0 seconds, but I have not done blind tests to back this up so for the sake of scientific certainty and logical positivism this would not be considered evidence, or for some of us here not even real.
   
  Personally I would not want to do blind tests rapidly switching out USB cables while the computer is switched on as device manufacturers generally do not condone this and suggest turning off the computer first.  Either way though a blind test would be no different than a sighted comparison save for the additional mental load of trying to figure out which is which and what to listen for etc.  Buffer size would be easier to do but would require an assistant.  Either way a blind test is a good way of bringing grandiose claims about "night and day differences" back to earth and showing that in reality the differences are not so night and day.  Having said this I wish I still had my $300 Audiophool USB controller card as that was clearly different to the motherboard USB ports, but also clearly colored and not in any way technically superior, but I sold that one off long ago and spend the money on something more useful.  In that case thought I observed an overall coloration of the audio, but no dropouts at all.


----------



## mikeaj

Quote: 





bigshot said:


> A faulty digital cable can't create an overall coloration to the sound. There has to be some other cause.


 
   
  Suddenly I'm getting dirty ideas about new audiophile products, a USB cable in particular.
   
  Put a USB receiver (slave I guess), a DSP, and a USB transmitter (master) inside the cable, all powered off the USB bus of course.  With those thick audiophile cables, you might be able to hide the chips along the length or more likely, inside one of the beefy plugs.  Have the USB receiver get the data from the source, pass it to the DSP, have the DSP apply an EQ to roll off the highs or apply some secret sauce filter, and pass that output to the USB transmitter.  (Maybe you need a microcontroller as well?)  Of course, this USB "cable" is directional.


----------



## gattari

Well, today I have buy a ferrite and apply it to another cable, and yes, the result is the same as Sony camera cable. 
At this point I strong raccomand to any odac possessor to experiment an usb cable with ferrite. This approach, for my experience, is a step up very important and clear for the overall quality reproduction of odac. Anyone have an explanation for this? 
It is not a small step up it is a very clear step up. 
Ciao

Inviato dal mio GT-I9300 con Tapatalk 2


----------



## gattari

I am curious if anyone with different dac try this little mod with ferrite to connect the usb cable with dac. 
I know ferrite 

Inviato dal mio GT-I9300 con Tapatalk 2


----------



## ultrabike

My only guess is that noise is coupling to your ODAC through the USB cable, and somehow the ferrite takes care of that. But AFAIK the ODAC uses quite a bit of filtering and split power supplies to get around this issue... It might be a faulty ODAC build...


----------



## ultrabike

Quote: 





gattari said:


> I am curious if anyone with different dac try this little mod with ferrite to connect the usb cable with dac.
> I know ferrite
> Inviato dal mio GT-I9300 con Tapatalk 2


 
   
  I have... When using my HeadRoom's Total BitHead and could not tell the difference when using it out of my Dell 1505 and HP laptops FWIW.


----------



## gattari

ultrabike said:


> My only guess is that noise is coupling to your ODAC through the USB cable, and somehow the ferrite takes care of that. But AFAIK the ODAC uses quite a bit of filtering and split power supplies to get around this issue... It might be a faulty ODAC build...



Somewhere, I reading that jds lab include an usb cable with ferrite. 
Perhaps this is a reason for this. 
Mine is an ephipany e-DAC. 
Definitely ferrite help much more than I aspect. 

Inviato dal mio GT-I9300 con Tapatalk 2


----------



## billybob_jcv

What does this mean?

From usb_20.pdf found here: http://www.usb.org/developers/docs/usb_20_071012.zip

Page 142: 
"Use of ferrite beads on the D+ or D- lines of full-speed devices is discouraged."

Page 143:
 "The use of ferrites on high-speed data lines is strongly discouraged."

I was always under the impression that ferrite beads were used on substandard cables, but that on cables that are fully compliant with the USB 2.0 spec, they are not needed (and perhaps discouraged?)

I was also under the impression that a ferrite bead is a choke - a passive low-pass filter. They are used to eliminate EMI/RF noise. I was also under the impression this noise is well beyond the audio frequency range. How that would affect the audio encoded in a digital signal without also affecting the digital signal itself is beyond me.


----------



## drez

Personally I don't like ferrite clamps, I tried a bunch of different applications a while ago and found in each instance the effects were damaging to SQ.  IMO ferrites are an easy way to colour the sounds and make a discernable difference to the SQ, and given how subjective musical tastes are some people will hear the difference and call it an improvement.  It is way easier to make a bad USB cable than it is to make one that makes a difference through improving signal transfer.


----------



## mikeaj

Quote: 





billybob_jcv said:


> What does this mean?
> From usb_20.pdf found here: http://www.usb.org/developers/docs/usb_20_071012.zip
> Page 142:
> "Use of ferrite beads on the D+ or D- lines of full-speed devices is discouraged."
> ...


 
   
  A ferrite bead is like an inductor, except at high frequencies (also depending on model type, construction) the impedance is both high and also mostly resistive.  i.e. most of the energy in the high frequencies gets dissipated.  As you say, if it's in series with the load, you're thus lowpass filtering the signal so the load doesn't get as much of the high frequencies.  The data lines in USB are carrying high-frequency signals.  You don't want to lowpass filter them (out) if you want the other side to actually get the signal.
   
  The ferrite bead is for filtering the +5V (supposed to be DC) line.  The filtering is both for keeping the crud from the source out of the destination and vice versa.  Or from other RF sources, though of course computers have plenty of high-speed clocks and switching devices already, even before you consider the actual radios.
   
  The concern is with the RF noise getting into the DAC and affecting the D/A.  These devices perform better with cleaner power.  Noise at RF frequencies matters because... wait, somebody else better explain this to me too.  That said, most DACs are oversampling or otherwise performing actions at frequencies much higher than audio, prior to the output reconstruction filter.
   
  To be honest, electronics and RF/EMI issues are way out of my specialty...


----------



## ultrabike

billybob_jcv said:


> What does this mean?
> From usb_20.pdf found here: http://www.usb.org/developers/docs/usb_20_071012.zip
> Page 142:
> "Use of ferrite beads on the D+ or D- lines of full-speed devices is discouraged."
> ...


 
   
  Mikeaj beat me to it 
	

	
	
		
		

		
			





, but here are my 2 cents:
   
  That is a good point. Here is a post I found interesting about it:
http://www.head-fi.org/t/353613/high-quality-usb-cable-for-usb-dac/75#post_4753989
   
  Ferrite beads effect on signal integrity probably depends on the cable length and gauge. Also, USB digital signals are well above the audio frequency range (partly depending on sampling rate and bit-width,) and may be affected by EMI/RF, and ferrite beads. That said, I don't see how this would be a big deal if the USB cables are standards compliant, unless the conditions are extremely noisy.


----------



## Eisenhower

Quote: 





liamstrain said:


> Line noise in a USB cable would be irrelevant at the D/A conversion point unless it was so problematic as to actually affect the voltage swing enough to switch bits (extremely unlikely).
> 
> Any noise you hear after the D/A conversion would more likely be coming from somewhere else in the chain and should be unaffected by the USB cable. I could see maybe some case if the amplification circuit is powered via the USB... a ferrite choke cost about $2, and would be any easy thing to add to any USB cable to test if you continue to think that the culprit lies there.
> 
> You state you heard differences between them. Did you do any sort of controlled/blind testing or ABX to determine this, or is this based on your own cable switching and general impressions.


 
   
  This post should have ended the thread. *USB cables do not effect sound quality*. This is a fact. *If you think they do, you are wrong.*


----------



## drez

Exactly, everything which has not yet been proven is wrong, and what is supported by current research is the only possibly truth, regardless of scope.  Only dualisms can exist.  The current understanding of the world I have is valid, and anything which is outside or opposed to this is completely invalid.  Kudos.


----------



## Eisenhower

Quote: 





drez said:


> Exactly, everything which has not yet been proven is wrong, and what is supported by current research is the only possibly truth, regardless of scope.  Only binary dualisms can exist.  The current understanding of the world I have is valid, and anything which is outside or opposed to this is completely invalid.  Kudos.


 
   
  Any claim that contradicts basic theoretical knowledge, and hasn't been shown experimentally, is wrong.
  I am tired of being nice to these claims, saying things like "maybe there is a way.. I don't how, but maybe... who knows?", if that is what you are implying I do. If there are any objective truths in the world, USB cables not affecting sound quality is one of them.
   
   
  Also, a binary dualism would have 4 possible outcomes...


----------



## drez

Quote: 





eisenhower said:


> Any claim that contradicts basic theoretical knowledge, and hasn't been shown experimentally, is wrong.
> I am tired of being nice to these claims, saying things like "maybe there is a way.. I don't how, but maybe... who knows?", if that is what you are implying I do. If there are any objective truths in the world, USB cables not affecting sound quality is one of them.
> 
> 
> Also, a binary dualism would have 4 possible outcomes...


 
   
  SO I guess you have an expert knowledge of USB audio and have conducted blind tests on USB cables as used in DAC's and SPDIF interfaces?  I guess you have had experience comparing USB cables in a stereo setup which is transparent enough for audio production?  Or have you just been reading some sound science articles and lurking in HydrogenAudio a little?
   
  I think it is quite clear what I mean by binary dualism, as in binary thinking which relies on a dualistic view of a topic at hand.  IE USB cables either affect audio or they don't.  Either something is in agreement with accepted standards of testing and a greater body of theory or it is wrong.  Seems binary to me.
   
  I don't care for you to tenderly word your opposition to the claim that USB cables can affect audio, or that your understanding of electronics and audio technology is in disagreement with the idea that USB cables can make a difference to audio.  I clearly understand why USB cables should not affect sound quality, I have done plenty of reading in this area and have spend a lot of time researching USB and computer audio.  I also understand the limits of my understanding in these areas and of the research I have conducted so far, as well as the limits of my hearing and of the reliability of testing without proper controls.
   
  But anyway thank you for your valuable insight it has contributed greatly to this thread.  SO kind of you to tell me that I am wrong.  I had never even considered it before.


----------



## AKG240mkII

Quote: 





eisenhower said:


> This post should have ended the thread. *USB cables do not effect sound quality*. This is a fact. *If you think they do, you are wrong.*


 

 This thread belongs in the voodoo-section "http://www.head-fi.org/f/21/cables-power-tweaks-speakers-accessories-dbt-free-forum"
  USB-cables do not transfer audio, they transfer zeros and ones .  There IS no audio until the DAC has done it's job .


----------



## drez

Quote: 





akg240mkii said:


> This thread belongs in the voodoo-section "http://www.head-fi.org/f/21/cables-power-tweaks-speakers-accessories-dbt-free-forum"
> USB-cables do not transfer audio, they transfer zeros and ones .  There IS no audio until the DAC has done it's job .


 
   





 The USB cable carries PCM data transferred via the USB bus - it carries audio information just you can't wire your headphones directly into the USB port.
   
  If this thread was moved to the cables subforum there might be a few less useless posts to contend with, but some people on the science forum actually have good insight into the technology, have conducted DBT's etc (not me personally.)  Others just seem more interested in trying to stir audiophiles.  There is a place for that and it is called HydrogenAudio.


----------



## bigshot

Ike is basically right. On the continuum of things a hifi nut needs to pay attention to, usb cables are down there with the color of carpet and whether you're going to let the dog sit on the leather sofa or not.


----------



## drez

Quote: 





bigshot said:


> Ike is basically right. On the continuum of things a hifi nut needs to pay attention to, usb cables are down there with the color of carpet and whether you're going to let the dog sit on the leather sofa or not.


 
   
  In the grander scheme of things you are probably right - if something cant be detected in DBT it's probably not that important...


----------



## Eisenhower

Quote: 





drez said:


> SO I guess you have an expert knowledge of USB audio and have conducted blind tests on USB cables as used in DAC's and SPDIF interfaces?  I guess you have had experience comparing USB cables in a stereo setup which is transparent enough for audio production?  Or have you just been reading some sound science articles and lurking in HydrogenAudio a little?
> 
> I think it is quite clear what I mean by binary dualism, as in binary thinking which relies on a dualistic view of a topic at hand.  IE USB cables either affect audio or they don't.  Either something is in agreement with accepted standards of testing and a greater body of theory or it is wrong.  Seems binary to me.
> 
> ...


 
   
  I took a DSP class at my university, not that it matters, since you ought to judge an argument on technical merit and not on the background of the person that makes it. Doing so is what is referred as an _ad hominem_ fallacy. Saying "binary dualism" is what is known as _tautology_, because you are saying the same thing twice. Seeing as you believe USB cables might change sound quality, I am not surprised you are using "binary" incorrectly...
   
  One of the reasons digital signals are used for telephones, TV, etc. is because they are not affected by the cable. It is a 1 or a 0. A digital signal is either transmitted or it isn't. Either a usb cable is functioning, or it isn't (one might call those binaries, or maybe dualisms, but certainly not binary dualisms). A $400 silver USB cable isn't going to improve the quality of the transmitted 1's and 0's, creating a subtle expansion of the soundstage. If it did, then there is something seriously wrong with your DAC. But anyone spending $400 on a USB cable will probably be using a functioning DAC.
   
  As for jitter (since USB audio is not time corrected) even a moderately long USB cable will not affect jitter in an audible way. That is why there haven't been any blind listening tests showing that USB cables affect sound quality. Do people keep their sources that far away from their DAC that it would affect sound quality? NO.
   
  Making claims that are based on fantasy are no more a valuable insight than dismissing them - claims made without evidence can be dismissed without evidence.
*In order to make progress in hi-fi audio, you have to accept that certain claims are in fact* *wrong*.


----------



## goodvibes

Quote: 





purrin said:


> Because any dielectric will polarize the electrons. Essentially the cable becomes a capacitor.
> 
> The EMI theory however is more sound. I actually got a subtle, but notable improvement by wrapping my USB cable with aluminum foil.


 

  Sorry, I couldn't help but make the joke even though I can see the foil helping. I could help it and I've done the same for various RF issues in the past. I could see it helping if there was spurious dig noise which would be expected in modern computer based systems.


----------



## drez

Quote: 





eisenhower said:


> I took a DSP class at my university, not that it matters, since you ought to judge an argument on technical merit and not on the background of the person that makes it. Doing so is what is referred as an _ad hominem_ fallacy. Saying "binary dualism" is what is known as _tautology_, because you are saying the same thing twice. Seeing as you believe USB cables might change sound quality, I am not surprised you are using "binary" incorrectly...
> 
> One of the reasons digital signals are used for telephones, TV, etc. is because they are not affected by the cable. It is a 1 or a 0. A digital signal is either transmitted or it isn't. Either a usb cable is functioning, or it isn't (one might call those binaries, or maybe dualisms, but certainly not binary dualisms). A $400 silver USB cable isn't going to improve the quality of the transmitted 1's and 0's, creating a subtle expansion of the soundstage. If it did, then there is something seriously wrong with your DAC. But anyone spending $400 on a USB cable will probably be using a functioning DAC.
> 
> ...


 
   
  I'm sorry I didn't realise that you raised an argument, in fact I would classify your first post as a comment, and with the basic message intended to tell people who do not agree with your viewpoint that they are wrong.  Criticising tautologies is just a way of playing grammar nazi.  You understood perfectly what I was saying but chose to focus criticism on an insignificant error of syntax. If the intention were different I would appreciate the correction.  I am here to learn.
   
  I'm guessing you have captured the digital signal coming out of this $400 silver USB cable so you can say for sure that there has been no influence over the jitter of the signal?  Can you tell us what magnitude and type/s of jitter this $400 USB cable you speak of has introduced against a reference USB cable?
   
  You are correct that USB audio is not time corrected, and most asynchronous devices have a  buffer on the receiver side.  Previously we have discussed that USB cannot transfer the audio bit by bit as the frequency of the bus is not high enough, therefore it must be using some kind f bulk transfer.  This is fair enough and I understand that this means that timing variances from the computer should not affect the signal at the other side of the USB device an a meaningful way, at least based on my limited understanding - I am not an expert in the field.
   
  Some people for whatever reason do use quite long USB cables, personally I do not as my gear is not spaced that far.
   
  Making claims based on fantasy is not what I am here to do, but if you notice other posters who have been on this forum a little longer tend to ask for further evidence or point to where any specifici fantasy is flawed rather than *telling people they are wrong *which lets face it will not influence anyone and will not contribute toward the general wellbeing of the thread, and is most likely an attempt to stir up people rather than contribute toward the thread.
   
  I have a different philosophy, which is in order to make progress in hifi I chose to trust my ears, whether testing an a mplifier or testing a headphone, or even a cable.  I do not offer this as "evidence" to anyone, it is my opinion based on my experience and I encourage others to share their experience or opinion even if it contrary to my own.
   
  It seems this thread has descended into an opprtunity to stirr up audiophiles, so I htink it might be best to bring a mod in to get the thread back on track.


----------



## bigshot

We've gone over this stuff over and over again, and the pattern is the same every time. First someone makes a statement about an effect that can't be measured or proven. Then the regulars answer it with facts and suggestions for how to objectively verify the effect. Then the person who made the unsupportable claim comes back saying science doesn't know everything. Then the regulars say "prove it exists". Then the person making the claims gets mad. Pretty soon the mods are called in and the thread is locked.

We aren't mad. We don't need to be protected by the mods. We are never the ones who cry to the mods to lock threads. We're just talking about observable phenomenon.

Just saying the effect doesn't exist is cutting to the chase in the hopes that it won't go down the road of anger and hard feelngs. If you are willing to discuss what you are theorizing, and subject it to objective tests without getting mad, we're happy to play. But it never goes that way. It always goes down the road of anger.


----------



## drez

Quote: 





bigshot said:


> We've gone over this stuff over and over again, and the pattern is the same every time. First someone makes a statement about an effect that can't be measured or proven. Then the regulars answer it with facts and suggestions for how to objectively verify the effect. Then the person who made the unsupportable claim comes back saying science doesn't know everything. Then the regulars say "prove it exists". Then the person making the claims gets mad. Pretty soon the mods are called in and the thread is locked.
> We aren't mad. We don't need to be protected by the mods. We are never the ones who cry to the mods to lock threads. We're just talking about observable phenomenon.
> Just saying the effect doesn't exist is cutting to the chase in the hopes that it won't go down the road of anger and hard feelngs. If you are willing to discuss what you are theorizing, and subject it to objective tests without getting mad, we're happy to play. But it never goes that way. It always goes down the road of anger.


 
   
  I don't think this is an accurate representation of the dialogue between myself and Eisenhower, my beef is not with challenges to any particular theory someone may have but to general and inflammatory attempts to make universal declarations that something is right or wrong, chest beating, or attempt to put someone down rather than addressing a specific argument or idea.
   
  The method in which an argument or opinion is delivered is what decides whether or not anyone will get angry.  Playing grammar nazi is again not what I would consider to be a mature and respectful way to make an argument (again I am referring to the dialog between Eisenhower and myself.)


----------



## Eisenhower

Quote: 





drez said:


> I'm sorry I didn't realise that you raised an argument, in fact I would classify your first post as a comment, and with the basic message intended to tell people who do not agree with your viewpoint that they are wrong.  Criticising tautologies is just a way of playing grammar nazi.  You understood perfectly what I was saying but chose to focus criticism on an insignificant error of syntax. If the intention were different I would appreciate the correction.  I am here to learn.
> 
> I'm guessing you have captured the digital signal coming out of this $400 silver USB cable so you can say for sure that there has been no influence over the jitter of the signal?  Can you tell us what magnitude and type/s of jitter this $400 USB cable you speak of has introduced against a reference USB cable?
> 
> You are correct that USB audio is not time corrected, and most asynchronous devices have a  buffer on the receiver side.  Previously we have discussed that USB cannot transfer the audio bit by bit as the frequency of the bus is not high enough, therefore it must be using some kind f bulk transfer.  This is fair enough and I understand that this means that timing variances from the computer should not affect the signal at the other side of the USB device an a meaningful way, at least based on my limited understanding - I am not an expert in the field.


 
   
  I reposted liamstrain's point. Why would I make an argument when someone's already made it for me? Having a correct understanding of digital audio is not a viewpoint. We aren't discussing politics, we are discussing fact based science.
   
  So let me get this straight, you questioned my credentials, when you yourself have none? That is hypocritical.
  It also isn't fair to demand that *I* must disprove *your* wildly nonsensical claim that USB cables affect sound quality. You are making the extraordinary claim, so you provide the evidence. This is how it works.
   
  I am not a grammar nazi, unless someone tries to sound intellectual with fancy sounding ostentatious concepts like "binary dualism" that actually don't make any sense. I also don't like it when people use sarcasm instead of making their point directly, which is what you did in your first response.


----------



## Clarkmc2

eisenhower said:


> It also isn't fair to demand that *I* must disprove *your* wildly nonsensical claim that USB cables affect sound quality. You are making the extraordinary claim, so you provide the evidence. This is how it works.




^This.^ Always, no exceptions.


----------



## drez

Quote: 





eisenhower said:


> I reposted liamstrain's point. Why would I make an argument when someone's already made it for me? Having a correct understanding of digital audio is not a viewpoint. We aren't discussing politics, we are discussing fact based science.
> 
> So let me get this straight, you questioned my credentials, when you yourself have none? That is hypocritical.
> It also isn't fair to demand that *I* must disprove *your* wildly nonsensical claim that USB cables affect sound quality. You are making the extraordinary claim, so you provide the evidence. This is how it works.
> ...


 
   
  What do you expect honestly, that this thread stays inactive until someone does a DBT, and that nobody should discuss anything until this takes place?  
   
  Why do I question your credeitials, well actually that is a good question, as you were not actually making an argument so much as commenting on someone else's argument and suggesting that it should somehow conclusively demostrate that USB cables do not affect audio and that anyone that thinks  they do are wrong.  Sorry but to me this statement has a tone of authority certainty to it, and without a supporting argument I am left wondering what has led you to this conclusion certainty.
   
  I am confused as to which particular argument about USB cables making an audible difference you are referring.  If you want a theory I have concocted about how USB cables might affect audio I can offer one, and my most recent posts have been a dialog with another member who thinks ferrite beads have an audible effect on his USB interface/DAC.  I have a feeling that this is of no interest to you so I will spare you the trouble of reading my ideas.
   
  I'm sorry if "binary dualism" sounded ostentatios and fell short gramatically - my original post was more direct but less polite.  I even considered posting nothing but I couldn't resist.  My understanding is that whether or not a claim is outlandish, experimentation is equally necessary to prove or disprove the claim, and if you are arguing against the claim on a theoretical basis, then a concise theoretical argument is needed with calculations, figures, specifics, case studies etc.
   
  Again telling someone they are wrong off the cuff is not an effective way of convincing them of your point of view, it is however a very effective way of creating offense.  If a claim is "wildly nonsensical" and you wish to make this point, you must follow this up and demonstrate why this claim is wildly nonsensical.  I thought we were discussing fact based science - that works both ways.


----------



## AKG240mkII

USB-cables DO NOT carry music !
  They are used to move zeros and ones ..
  Either the zeros and ones are there, or they are not .
  A cable can not magically change anything, it does not make the zeros and ones sound 'warmer' 'better' or anything else .
   
   
   
  Quote: 





> Again telling someone they are wrong off the cuff is not an effective way of convincing them of your point of view


 
   
  You can cook up all the theories you want, there is NO factual evidence to support the claim that a non-defective USB-cable
  affects anything . And it IS up to you to provide evidence for your theory .
  This is not about OPINION, it is FACT !


----------



## drez

Quote: 





akg240mkii said:


> USB-cables DO NOT carry music !
> They are used to move zeros and ones ..
> Either the zeros and ones are there, or they are not .
> A cable can not magically change anything, it does not make the zeros and ones sound 'warmer' 'better' or anything else .
> ...


 
   
  A fact requires evidence where is your evidence?  I have made no statement of fact, please quote where I have said that USB cables affect sound quality.
   
  If you want to say an idea is unproven and unsupported by electrical engineering/science theory, then you do not have to provide evidence, but may be required to specify which parts of electrical theory you find to suggest that USB cables cannot affect sound quality.  The argument you have offered above is an oversimplification of how USB audio works and the performance factors involved.  
   
  If you want to say the theory is wrong. as in not possible, then you need to provide evidence.  Absence of proof is not proof of absence.
   
  if a scientist wants to say that shark cartilage cannot improve arthritis, he has to conduct experiments.  before his experiments, he can say that "there is no evidence that shark cartilage can improve arthritis" and even after the experiment he can say that there is no evidence and that there is a strong indication that the shark cartilage is not effective.  Bottom line is that before providing your own evidence you cannot declare that something is *impossible*, you can only say there is no experimental evidence or support in theory.  If you are solely basing your argument on theory, it might be helpful to outline how scientific theory does not support the idea you disagree with.
   
  If some of these posts were answers to a science exam I'm pretty sure they would get an F.  If we are trying to discuss things in a scientific manner, then fine, be my guest and post acceptably scientific arguments.
   
  It really seems like we are arguing about completely different things here...


----------



## proton007

@drez:
  As such, it will be hard if everyone wishes to re-prove a theory, or an accepted standard. It takes a lot of effort and testing to prove and establish standards, so when it comes to USB standards, you can pretty much take them for proof, *after* understanding how USB Audio is implemented.
   
  From the USB specification, the three types of Isochronous transfer (Synchronous, Adaptive and Asynchronous) have different levels of immunity to jitter, with Synchronous being least immune, to Asynchronous that uses separate clocks on the host and ADC (The device needs to maintain a buffer of packets to compensate for any host jitter, but once buffered, the internal clock is used by ADC, hence no jitter)
   
  That said, a USB cable is not mentioned anywhere in the USB Audio standard, and will work as specified by the standard as long as it meets the USB requirements.
   
If you choose a jitter prone transfer method (Synchronous), too bad. Even a 1 million dollar cable cannot save you.
   
  Finally, jitter or no jitter, the end result is not correlated to the cable cost or metal purity, as long as the cable meets the electrical requirements. The USB standard transfers data. Once the data is pushed from host to device, reliably, there's nothing more a cable can do. And USB guarantees the data will be transferred reliably if you meet their standard.
   
  Now please don't ask me to conduct a study with all the cables in the name of *evidence*. 
   
  Even after all this, I still cannot fathom how the analog reproduction of sound can have anything to do with the USB cable.


----------



## drez

Quote: 





proton007 said:


> @drez:
> As such, it will be hard if everyone wishes to re-prove a theory, or an accepted standard. It takes a lot of effort and testing to prove and establish standards, so when it comes to USB standards, you can pretty much take them for proof, *after* understanding how USB Audio is implemented.
> 
> From the USB specification, the three types of Isochronous transfer (Synchronous, Adaptive and Asynchronous) have different levels of immunity to jitter, with Synchronous being least immune, to Asynchronous that uses separate clocks on the host and ADC (hence no jitter).
> ...


 
   
  Interesting argument, but is this a matter of working or not working, or jitter immunity or lack thereof.  USB itself was developed as a low cost solution, Firewire on the other hand was designed for best performance with timing sensitive devices.  This said I have no idea how you could improve on the reference design offered in the USB specification, as you say the standard was developed specifically to work with the USB interface, and similarly I can't see any reason why the type of metal used for the conductor would be a significant influence save for silver having lower resistance than copper.  If asynchronous transfer is jitter immune I can't explain some of the experiences I have had with different asynchronous devices and drivers, USB controllers etc. other than writing them off as placebo, which I strongly consider not to be the case.  The only convincing difference in USB cables I have heard was between an extremely short USB cable and one of standard length - I do not consider USB cables of similar length to make a significant difference such that I can I am 100% sure there is a difference passable in a blind test.  I have also not been intensively comparing USB cables lately, I just listen to my music and try and enjoy the experience.


----------



## ultrabike

I think mostly it is a matter of working or not working.


----------



## bigshot

drez said:


> my beef is not with challenges to any particular theory someone may have but to general and inflammatory attempts to make universal declarations that something is right or wrong,




Making a declarative statement without equivocation about a subject one is very familiar with is NOT inflammatory. If you can't abide people who speak in a forthright manner, internet forums are not for you. When you react to someone who has made an informed forthright statement by threatening to bring the mods in to shut down the thread because you are offended, you're the one who is fanning the flames. If you really want a civil discussion, the best way to encourage that is to lead by example.


----------



## proton007

Quote: 





drez said:


> If asynchronous transfer is jitter immune I can't explain some of the experiences I have had with different asynchronous devices and drivers, USB controllers etc. other than writing them off as placebo, which I strongly consider not to be the case.


 
   
  So given this ^^ vs the USB standard, what do you think I'll trust more when it comes to the cable argument?
   
  And the standard works well for what is required of it. In any case, the usb-cable-to-sound causation has been debunked.


----------



## grokit

I'm on Drez's side, I trust my ears and have found different USB cables to sound... differently. I'm sure that they all conform to USB standards.


----------



## bigshot

Well if you have usb cables that sound dramatically different, you should find someone to test them and find out exactly how much and why. You're sitting on a major technological exception to general knowledge.


----------



## ultrabike

Quote: 





grokit said:


> I'm on Drez's side, I trust my ears and have found different USB cables to sound... differently. I'm sure that they all conform to USB standards.


 
   
  You should definitively trust your ears... but those differences might have been headphone positional variations, too much scotch, or something else...


----------



## Lorspeaker

""the life is in the blood"".....the listening


----------



## bigshot

Alcohol is in my blood!


----------



## proton007

Quote: 





ultrabike said:


> You should definitively trust your ears... but those differences might have been headphone positional variations, too much scotch, or something else...


 
   
  On a side note.
   
  A couple of days ago, I overclocked my PC processor to 4.4GHz. I use linux, when I booted after changing the settings, it was like, OMG...everything is faster......I'm in overclock nirvana....until I checked the cpu speed. 
  The damn thing was running at 1.6GHz (on demand frequency scaling) and 1.6GHz is the lowest that CPU will run at. Until I changed it to performance (max speed, 4.4 GHz), at which point the difference was miniscule, if any, and my excitement had worn off.
   
  Point being, the default speed was good enough. Same goes for cables.
   
  Now I can say I trust my eyes and OMG I saw it!! Everything was fast. In reality it wasnt.


----------



## ultrabike

Quote: 





proton007 said:


> On a side note.
> 
> A couple of days ago, I overclocked my PC processor to 4.4GHz. I use linux, when I booted after changing the settings, it was like, OMG...everything is faster......I'm in overclock nirvana....until I checked the cpu speed.
> The damn thing was running at 1.6GHz (on demand frequency scaling) and 1.6GHz is the lowest that CPU will run at. Until I changed it to performance (max speed, 4.4 GHz), at which point the difference was miniscule, if any, and my excitement had worn off.
> ...


 
   
  Nah, it was the scotch...


----------



## drez

Quote: 





proton007 said:


> So given this ^^ vs the USB standard, what do you think I'll trust more when it comes to the cable argument?
> 
> And the standard works well for what is required of it. In any case, the usb-cable-to-sound causation has been debunked.


 
   
  I wouldn't suggest that anyone should trust what I am hearing, not only because we all have different standards for comparing audio and the whole trust issue that you raised, but also because we all hear things differently and have different equipment, music etc.  As ultrabike says there are also many possibilities for why someone might hear things differently when testing cables which are difficult to factor in.  All I am willing to say is that for computer audio I have found that things which one might not think make a difference appear to make a difference, for me at least.


----------



## bigshot

I've found that the best way to improve the sound of your system is to understand how it works, identify problems, directly address them, and verify your results. That way you always move forward.

If you try random things that you don't really understand, you get random results. I've made huge improvements on my system over the years, and knowing why was a big part of what I achieved.


----------



## BlackbeardBen

Quote: 





ultrabike said:


> Nah, it was the scotch...


 
   
  Or was it Bourbon?


----------



## proton007

Quote: 





blackbeardben said:


> Or was it Bourbon?


 
   
  Neither...I'm a teetotaler...which makes it even more compelling....how_can_my_eyes_deceive_me ??


----------



## proton007

Quote: 





bigshot said:


> I've found that the best way to improve the sound of your system is to understand how it works, identify problems, directly address them, and verify your results. That way you always move forward.
> If you try random things that you don't really understand, you get random results. I've made huge improvements on my system over the years, and knowing why was a big part of what I achieved.


 
  Agree.
  Propose something, based on some level of existing theory, and then verify the result. Thing is, first of all we need to establish some form of performance metrics to test. And that cannot be done unless we know what to expect.
  Most of the times when something random pops up, its more of a discovery. I'm hoping the cable faction is right, maybe they've discovered something we don't know. Until then, I'll view these claims with skepticism.


----------



## ultrabike

Quote: 





blackbeardben said:


> Or was it Bourbon?


----------



## drez

Quote: 





bigshot said:


> I've found that the best way to improve the sound of your system is to understand how it works, identify problems, directly address them, and verify your results. That way you always move forward.
> If you try random things that you don't really understand, you get random results. I've made huge improvements on my system over the years, and knowing why was a big part of what I achieved.


 
   
  This is one of the big problems in computer audio - people try to fix things that don't need fixing and make things worse in the process.  Then because we all have different tastes and random ideas of what jitter or noise sounds like there is a lot of journeys down the garden path and wasted money.  Unfortunately when it comes to computer audio and cables the knowledge and equipment needed to really understand what is going on is beyond most enthusiasts, but when some things are free to test, reversible etc. I don't see a lack of technical understanding or ability to empirically verify changes as reasons to abandon testing these components/variables.  Ideally it would be good to have enough technical understanding to know when something is doing more harm than good, but IMO if you train your hearing this is viable especially where changes can be quickly reverted back to the original setup.  If you really want to be sure of a change you could always do a blind comparison if you have somebody around who is willing to lend assistance in the test.


----------



## grokit

Random results often provide for the gestation of pure genius.


----------



## Griploc

Ok, so i havent as of yet done the dbt and or posted the usb pic as of yet.
I will be doing the dbt today after i get off work and posting a pic today as well


----------



## Griploc

Ive been super busy mixing and mastering a rap/techno album this week. I apologize to any that have been curious about the results. I did start using the usb cable and the directions say that there is a burn in stage of up to 150 hrs, i will also post this pic with the usb


----------



## ultrabike

Quote: 





griploc said:


> I did start using the usb cable and the directions say that there is a burn in stage of up to 150 hrs


 
   
  Wow, they even give you the USB cable burn in time!? 
	

	
	
		
		

		
		
	


	




 I only wished HP and Dell provided their laptop documentation with PCB traces, wiring, and inter-connectors burn in time! Neeed... mooore... dooos ... equis...


----------



## bigshot

drez said:


> This is one of the big problems in computer audio - people try to fix things that don't need fixing and make things worse in the process.  Then because we all have different tastes and random ideas of what jitter or noise sounds like there is a lot of journeys down the garden path and wasted money.  Unfortunately when it comes to computer audio and cables the knowledge and equipment needed to really understand what is going on is beyond most enthusiasts,




I don't think a basic understanding of how digital audio works is all that difficult. I think people are just too lazy to do the googling, so they assume spending a lot of money will get them the sound they want without going to all that trouble. They're lazy and they pay through the nose for it. Audio is pretty straightforward, and once you know how your ears work, you can give them what they need. It isn't difficult or expensive.

It's been my experience that when technical explanations start turning to swamps of molassas, it's because someone is starting to count angels dancing on the heads of pins. For instance, I'd love to have someone explain to me what jitter actually sounds like. When I spent a few days puzzling it all out, I came to the conclusion that not only is it extremely rare in home audio, it occupies a time frame so tiny, ears would likely pass right over it. Repeating patterns of gross amounts of jitter might affect upper frequencies, but I have yet to hear anyone say it sounds like that. That's probably because jitter flat out doesn't affect sound in any audible way.


----------



## bigshot

grokit said:


> Random results often provide for the gestation of pure genius.




That's how evolution works! If you're willing to wait from the Pleistocene to the Paleozoic for your sound quality to improve, random mutation is the way to go. I'm just a little too impatient for that myself.


----------



## bigshot

griploc said:


> I did start using the usb cable and the directions say that there is a burn in stage of up to 150 hrs




What fine commercial enterprise prepared these instructions, if I might ask?


----------



## joeyjojo

Interesting questions bigshot. As it might be semi-related could I point you clever lot at this thread http://www.head-fi.org/t/620094/dropouts-in-foobar-over-spdif-with-boinc-and-eist-solved
   
  In short, I used to run intensive computing progs in the background while listening to music through an Asus DX -> CA Dacmagic. Occasionally you'd hear very tiny clicks, but they were so quiet and brief as to be ignorable and I didn't realise it was a problem. Then I swapped the DX out for an M-Audio 2496 and it was terrible! Clicks more frequent and more disruptive to the music. However with BOINC switched off and speedstep disabled it was fine. Recently I've been using an AMB gamma2 (gone back to the DX) and it must be far more robust (it has a clever asynchronous something-or-other) as it seems to be immune to any of these problems regardless of what else is running.
   
  So what were these noises I was hearing? Perhaps they were this mysterious "jitter" caught in the act? Or buffer under runs? You can try the same thing yourself using a cpu stress test - something like prime95, Intel Burn Test, or LinX, and listen out.


----------



## ultrabike

Quote: 





joeyjojo said:


> So what were these noises I was hearing? Perhaps they were this mysterious "jitter" caught in the act? Or buffer under runs? You can try the same thing yourself using a cpu stress test - something like prime95, Intel Burn Test, or LinX, and listen out.


 
   
  It was the sweet sound of missing and/or wrong bits.


----------



## grokit

Quote: 





bigshot said:


> Quote:
> 
> 
> 
> ...


 
   
  Not random mutation, trying random tweaks to see what sticks. Who knows, could get lucky!


----------



## ultrabike

Quote: 





grokit said:


> Not random mutation, trying random tweaks to see what sticks. Who knows, could get lucky!


 
   
  HiFi audio Vegas style baby!


----------



## bigshot

Roll dem bones! Papa needs a new pair of cans!


----------



## jcx

http://en.wikipedia.org/wiki/Infinite_monkey_theorem
   
   
  don't expect them to do any better with soldering irons instead of typewriters


----------



## drez

Quote: 





ultrabike said:


> It was the sweet sound of missing and/or wrong bits.


 
   
  yes this would be my guess as well, dropouts are not jitter IMO.


----------



## drez

Quote: 





bigshot said:


> I don't think a basic understanding of how digital audio works is all that difficult. I think people are just too lazy to do the googling, so they assume spending a lot of money will get them the sound they want without going to all that trouble. They're lazy and they pay through the nose for it. Audio is pretty straightforward, and once you know how your ears work, you can give them what they need. It isn't difficult or expensive.
> It's been my experience that when technical explanations start turning to swamps of molassas, it's because someone is starting to count angels dancing on the heads of pins. For instance, I'd love to have someone explain to me what jitter actually sounds like. When I spent a few days puzzling it all out, I came to the conclusion that not only is it extremely rare in home audio, it occupies a time frame so tiny, ears would likely pass right over it. Repeating patterns of gross amounts of jitter might affect upper frequencies, but I have yet to hear anyone say it sounds like that. That's probably because jitter flat out doesn't affect sound in any audible way.


 
   
  I think it also depends on where the jitter is in the audio stream as well as what type of jitter, which are the components being affected, what are the jitter reduction mechanisms etc.  I agree 100% about throwing the money at the "problem."  I think there are a lot of misconceptions about computer audio and digital transports/cables, most of them probably inspired by some audiophile products/companies marketing material.  From my own experiences I have heard influence of some USB controllers, galvanic isolation etc. that spans the entire frequency spectrum as increased bloom and lack of focus - I have no idea how that works (none of the tweaks were better than USB straight out of the motherboard IMO.)  Keeping things simple, high quality and direct seems to win out over buying into miracle components, but some people seem to think that digital should sound like analog, and therefore that anything that sounds different to analog is jitter, forgetting that analog has much lower timing accuracy....


----------



## bigshot

I have a $120 Sony bluray player.it has no audible jitter. Jitter is not an audio problem. It's a sales tool.


----------



## drez

Quote: 





bigshot said:


> I have a $120 Sony bluray player.it has no audible jitter. Jitter is not an audio problem. It's a sales tool.


 
   
  I thin it might be both a sales tool and an audio problem, just that the problem is some audiophile companies selling products that actually perform badly and colour the sound.  I have no evidence for this but this is what I think is going on.


----------



## bigshot

It's pretty simple then to just buy inexpensive midline gear that outperforms the expensive stuff.


----------



## Lorspeaker

Last night I decided to park myself in front of the desktop instead of the laptop,
Took my dacportLX with stock usb with me n a HM5 along. Opened up tuneIn radio ...bossa nova ..nice.

Then I when back to my living room n hijacked a furutech gt2 USB cable n plugged it in...
The sound went from from nice to wowwww...I just love the whisky n the placebo..amazing furutech...slurpsssss.
This is FUN!!!


----------



## autumnholy

Quote: 





lorspeaker said:


> Last night I decided to park myself in front of the desktop instead of the laptop,
> Took my dacportLX with stock usb with me n a HM5 along. Opened up tuneIn radio ...bossa nova ..nice.
> Then I when back to my living room n hijacked a furutech gt2 USB cable n plugged it in...
> The sound went from from nice to wowwww...I just love the whisky n the placebo..amazing furutech...slurpsssss.
> This is FUN!!!


----------



## Currawong

Quote: 





bigshot said:


> I have a $120 Sony bluray player.it has no audible jitter. Jitter is not an audio problem. It's a sales tool.


 
   
  An interesting observation I made was with my Audiophilleo USB converter. Though it has jitter independently measured at below 1ps, I still felt there was some degree of unpleasant harshness in my system. Using it out of a better power supply (and not using the computer's power) improved things. Indeed, an upgrade to the power supply for it is not intended to improve the jitter at all, but improve the performance of the S/PDIF output. That removed the perceived harshness*.  I'm using this to illustrate a point, which is people tend to classify everything they think is wrong with digital audio to be the result of "jitter" when what is going on is fare more complex and are not something that needs a cable change to improve.
   
*Without the necessary $10k+ of equipment required to test what was going on accurately, I have no other means of testing what is going on, but as I've been saying for a while now, I'd like to be able to.


----------



## ultrabike

From what I've read so far, my understanding is that audible jitter is due to instantaneous and random variations of the DAC clock frequency. Since most USB audio transfers use Isochronous/Adaptive mode, clock is derived from the somewhat jittery USB data bits, resulting in a somewhat jittery DAC clock. Jitter in the data path may be due to poor host master clock, power sub-system noise (see Currawong above), horrible PCB trace issues, EMI/RF through the cable, etc... Several methods exist to attenuate said jitter like TI's SpAct deal in their pcm2704/5/6/7 ICs (http://www.ti.com/lit/ds/symlink/pcm2707.pdf)... There might be some re-clocking and alternative schemes to further reduce this jitter, like Benchmark's DAC1 UltraLock deal.
   
  As far as, how does jitter sound, in the case of a turntable or cassette player, the motor speed might instantaneously and randomly fluctuate... 'cuz motors are not infinitely precise. This would result in the analogous of DAC clock jitter. One could go DJ crazy on the turntable and hear crazy jitter. If jitter is bothering your ears, *a good DAC might help *(that is not necessarily the most expensive one, research helps.)
   
  As far as cables, they act as low pass filters which smear the signal, and result in jitter. A good, *standards compliant and not necessarily expensive USB cable*, should keep things relatively clean AFAIK, along with *a well regarded/proven USB interface/receiver* solution.
   
  There is one type of jitter that no amount of cables and true reference level USB receivers will be able to correct AFAIK: jitter in the actual recording.


----------



## bigshot

Audible jitter is extremely rare. It really isn't an issue.


----------



## nanaholic

Quote: 





joeyjojo said:


> Interesting questions bigshot. As it might be semi-related could I point you clever lot at this thread http://www.head-fi.org/t/620094/dropouts-in-foobar-over-spdif-with-boinc-and-eist-solved
> 
> In short, I used to run intensive computing progs in the background while listening to music through an Asus DX -> CA Dacmagic. Occasionally you'd hear very tiny clicks, but they were so quiet and brief as to be ignorable and I didn't realise it was a problem. Then I swapped the DX out for an M-Audio 2496 and it was terrible! Clicks more frequent and more disruptive to the music. However with BOINC switched off and speedstep disabled it was fine. Recently I've been using an AMB gamma2 (gone back to the DX) and it must be far more robust (it has a clever asynchronous something-or-other) as it seems to be immune to any of these problems regardless of what else is running.
> 
> So what were these noises I was hearing? Perhaps they were this mysterious "jitter" caught in the act? Or buffer under runs? You can try the same thing yourself using a cpu stress test - something like prime95, Intel Burn Test, or LinX, and listen out.


 
   
  My guess would be program thread priority, your CPU intensive programs where taking up CPU time such that the audio decoder got pushed down in priority which resulted in bad and/or interrupted decoding (it's pretty common back in earlier days when CPU weren't as powerful and we didn't have multi-core CPUs, like say 486 days, I can still remember interruption of music playback and introduction of distortion back then when I tried to fire up the browser or something intensive).  Also the way your CPU intensive programs taking up CPU would be relatively random depending on many random factors so you didn't get repeatable noise results.
   
  There are so many more plausible explanations to this than "USB cable induced jitter" that I would investigate in first.


----------



## joeyjojo

My point was that it's a good way of hearing for yourself the kind of artifacts that appear when a digital system isn't working optimally, i.e. obvious clicks and gaps, not subtle things like "wow" factor.


----------



## AKG240mkII

Quote: 





nanaholic said:


> My guess would be program thread priority, your CPU intensive programs where taking up CPU time such that the audio decoder got pushed down in priority which resulted in bad and/or interrupted decoding (it's pretty common back in earlier days when CPU weren't as powerful and we didn't have multi-core CPUs, like say 486 days, I can still remember interruption of music playback and introduction of distortion back then when I tried to fire up the browser or something intensive).  Also the way your CPU intensive programs taking up CPU would be relatively random depending on many random factors so you didn't get repeatable noise results.
> 
> There are so many more plausible explanations to this than "USB cable induced jitter" that I would investigate in first.


 
   
  How about occasional DPC's taking 50% CPU-time like certain EMU-devices ? (0202/USB)


----------



## ultrabike

Quote: 





bigshot said:


> Audible jitter is extremely rare. It really isn't an issue.


 
   
  Well, if the interfaces are within spec and reasonably well designed, there are* issues other than jitter*, that may have a stronger impact on performance... USB cables that meet the spec are not necessarily expensive... Monoprice sells them for about a $1 (may need to add tax and shipping though):
   
http://www.monoprice.com/products/product.asp?c_id=103&cp_id=10303&cs_id=1030301&p_id=8615&seq=1&format=2
http://www.monoprice.com/products/product.asp?c_id=103&cp_id=10303&cs_id=1030301&p_id=5437&seq=1&format=2
   
  Most headphone's FR and distortion, along with poorly recorded music, are usually more problematic IMO... Well, it was for me anyway.


----------



## liamstrain

Quote: 





joeyjojo said:


> My point was that it's a good way of hearing for yourself the kind of artifacts that appear when a digital system isn't working optimally, i.e. obvious clicks and gaps, not subtle things like "wow" factor.


 
   
  Yes. This. It works or it doesn't... it doesn't affect "soundstage" or the bass, or clarity - it drops out, clicks and gaps... that's all a USB cable or digital transfer protocol can be expected to work with.


----------



## proton007

Quote: 





liamstrain said:


> Yes. This. It works or it doesn't... it doesn't affect "soundstage" or the bass, or clarity - it drops out, clicks and gaps... that's all a USB cable or digital transfer protocol can be expected to work with.


 
   
  Agree. Even if you take it to the extreme, packet drops won't get audible until there's some real slowdown, I mean, if you're hearing clicks and gaps, your system is really screwed up. On the other hand, a couple of milliseconds won't be noticeable at all.
  Again, its still not related to USB cables.


----------



## ultrabike

liamstrain said:


> Yes. This. It works or it doesn't... it doesn't affect "soundstage" or the bass, or clarity - it drops out, clicks and gaps... that's all a USB cable or digital transfer protocol can be expected to work with.


 
  I agree too.


----------



## drez

Have you guys heard different USB transports - say at one end a cheapo older adaptive transfer one with single frequency oscillator compared to a newer USB transport with asynchronous transfer, dual high precision oscillators that measures well etc.  It's easier still to just compare the inbuilt USB on a DAC to one of the higher quality USB transports on the market.  If you are using a Benchmark DAC-1 that's cheating because of the asynchronous SPDIF inputs
	

	
	
		
		

		
			





.  You can even just buy an old HIFace and compare the stock HiFace driver to the Young DAC driver, or compare with or without a USB cable extension.  I don't have proof that these sound different (in my experience I think they do), but I am trying to understand where you are coming from regarding 'dropouts or perfect audio' thing.


----------



## dleblanc343

joeyjojo said:


> Interesting questions bigshot. As it might be semi-related could I point you clever lot at this thread http://www.head-fi.org/t/620094/dropouts-in-foobar-over-spdif-with-boinc-and-eist-solved
> 
> In short, I used to run intensive computing progs in the background while listening to music through an Asus DX -> CA Dacmagic. Occasionally you'd hear very tiny clicks, but they were so quiet and brief as to be ignorable and I didn't realise it was a problem. Then I swapped the DX out for an M-Audio 2496 and it was terrible! Clicks more frequent and more disruptive to the music. However with BOINC switched off and speedstep disabled it was fine. Recently I've been using an AMB gamma2 (gone back to the DX) and it must be far more robust (it has a clever asynchronous something-or-other) as it seems to be immune to any of these problems regardless of what else is running.
> 
> So what were these noises I was hearing? Perhaps they were this mysterious "jitter" caught in the act? Or buffer under runs? You can try the same thing yourself using a cpu stress test - something like prime95, Intel Burn Test, or LinX, and listen out.




I can report the same clicking noises. It is frequent with a generic usb cable, maybe once or twice per three minutes of music playback. The audioquest carbon also does the same but myabe a clip every three minutes only. The tellurium q usb cable so far has been almost flawless; in maybe 30 hours of playback in the past 3 weeks and i can only recall noticing one clippage in sound. All cables are 1.5 meters


----------



## drez

Quote: 





dleblanc343 said:


> I can report the same clicking noises. It is frequent with a generic usb cable, maybe once or twice per three minutes of music playback. The audioquest carbon also does the same but myabe a clip every three minutes only. The tellurium q usb cable so far has been almost flawless; in maybe 30 hours of playback in the past 3 weeks and i can only recall noticing one clippage in sound. All cables are 1.5 meters


 
   
  Ineteresting, can't say I have noticed anything similar on my system, but my setup is different as I am using USB transport with galvanic isolation connected to grounded computer and DAC on the same circuit.  So this is using USB from a laptop into a Bifrost DAC?  Without knowing what is inside the Tellurium Q cable it is hard to figure out what is going on there
	

	
	
		
		

		
		
	


	




  If we could debug the USB receiver then maybe we could say whether or not the cable is affecting the buffer management causing buffer underrun or whether the dropout is from some sort of electrical interference.


----------



## grokit

The Bifrost reportedly clicks when the sampling rate changes.


----------



## joeyjojo

As above if you're maxing out your cpu it's nothing to do with the cables, it's probably a buffer underrun. I was just pointing out that (working hypothesis) USB either works well, and no cable is going to change the sound; or it doesn't and you get big obvious noises like clicks and pops.
   
  One exception may be if the device is also USB powered, but then you should look at getting a better power supply instead of a premium cable.


----------



## drez

Quote: 





joeyjojo said:


> As above if you're maxing out your cpu it's nothing to do with the cables, it's probably a buffer underrun. I was just pointing out that (working hypothesis) USB either works well, and no cable is going to change the sound; or it doesn't and you get big obvious noises like clicks and pops.
> 
> One exception may be if the device is also USB powered, but then you should look at getting a better power supply instead of a premium cable.


 
   
  The theory among people developing audiophile computer programs etc seems to be that you get best performance by ensuring a smooth flow of data rather than one with unreliable latency caused by dropped packets, hardware interrupts etc.  One might say that the solution is to just use a larger buffer, but computer audiophiles tend to prefer to use as small a buffer as possible for whatever reasons that are beyond my understanding of digital sound processing (other than input delay).  My favorite music software can playback with "direct link" buffer setting and still maintain skip free, even in windows with a browser window running.  With other music software like Foobar I have to use above 30 ms otherwise there are skips, then again the software I use pretty much decodes and buffers the whole song into ram ahead of time, and even then has different playback engines which have subtle differences in sound and yet are bit perfect...  Probably getting pretty far out of sound science territory here but got a bit carried away talking about buffer management...


----------



## AKG240mkII

Quote: 





drez said:


> The theory among people developing audiophile computer programs etc seems to be that you get best performance by ensuring a smooth flow of data rather than one with unreliable latency caused by dropped packets, hardware interrupts etc.  One might say that the solution is to just use a larger buffer, but computer audiophiles tend to prefer to use as small a buffer as possible for whatever reasons that are beyond my understanding of digital sound processing (other than input delay).  My favorite music software can playback with "direct link" buffer setting and still maintain skip free, even in windows with a browser window running.  With other music software like Foobar I have to use above 30 ms otherwise there are skips, then again the software I use pretty much decodes and buffers the whole song into ram ahead of time, and even then has different playback engines which have subtle differences in sound and yet are bit perfect...  Probably getting pretty far out of sound science territory here but got a bit carried away talking about buffer management...


 

 You all need to realize that playback is not the same as recording ..
  Obviously, when recording, any 'latency' is unacceptable -
  YES, the guitarist,bassist, drummer whatever - *will* notice a 30ms delay from doing something till hearing it ..
  It's enough to make the drummer off-beat !
   
  When playing back a digital file from a computer - There is no such thing as 'latency' !
  You are NOT playing a LP-record, 'decoded' in 'real-time' .
  Ultimately, you will want the entire track read from disk to RAM and played from RAM without further disk-access .
  CD's are almost read like LP's - That's why Sony made a load of money on that 'anti-skip' thing on the Discmans .
  They did what foobar and all other computer-playback software does : Load it to RAM and play from there .


----------



## drez

Quote: 





akg240mkii said:


> You all need to realize that playback is not the same as recording ..
> Obviously, when recording, any 'latency' is unacceptable -
> YES, the guitarist,bassist, drummer whatever - *will* notice a 30ms delay from doing something till hearing it ..
> It's enough to make the drummer off-beat !
> ...


 
   
  I think you misunderstood me, I said I prefer to use a small buffer for reasons"other than input delay."
   
  There most definitely is such a thing as latency and it is there in varying amounts at every stage of the computer setup.  You want to to input a command to a music player, there is latency, to access a hard disk, there is latency, you have different bus speeds, different speeds of data flow, and on top of this data does not usually arrive in a smooth manner so you need buffers at strategic points to ensure there is a constant flow of data and no dropouts.  If you have a problem where the latency is inconsistent (very typical in Windows machines) you need a larger buffer, or on the other hand you can use techniques like ram disk etc to ensure a smoother flow of data and therefore not need such a large buffer.  You can also not use a ram disk at all and just use a larger size buffer, but I find that this does not sound as good to my ears.  Most music software do not load the entire file into ram, they instead load a number of samples ahead of time thus use a buffer.  Audio data coming out of a USB port does not have consistent timing, which is why timing correction mechanisms are needed at the USB receiver, maybe even another buffered control mechanism.  IMO none of these systems are perfect at fixing timing issues, whether this is audible is another matter.
   
  The simplistic view is that you can just use a large buffer at any stage and you will get perfect results, but in my opinion this is not the case, as in I believe the buffer size and nature affects the sound quality.  You may not hear any differences from these settings and this is fine.  Even if I could provide evidence for any of my opinions I do not think it would be in anyone's interest.  I could for argument's sake throw a million ferrite beads on a USB cable, prove I can hear a difference with DBT and then say a million ferrite beads sounds better, but still not be contributing anything useful.  What I mean to say is that audio is so inherently subjective that even if a difference can be heard, people will not agree on whether there is an improvement.  IMO If you are really interested in something you need to do your own research and not rely on extrapolation and prediction from other peoples research, and not mistake one (or more) negative result/s for a universal truth in circumstances outside the scope of the test setup.  If you don't worry about subtle differences in sound quality then you could just not do the testing and direct your efforts elsewhere.


----------



## bigshot

I've found that I do a lot better improving the sound of my system by not surrendering to pure subjectivity. I get great results by figuring out how things work and addressing specific problems. Sound isn't magic. It's fairly easy to understand and control.
   
  If you're getting skipping, you need a buffer. It's pretty simple.


----------



## dleblanc343

Quote: 





drez said:


> Ineteresting, can't say I have noticed anything similar on my system, but my setup is different as I am using USB transport with galvanic isolation connected to grounded computer and DAC on the same circuit.  So this is using USB from a laptop into a Bifrost DAC?  Without knowing what is inside the Tellurium Q cable it is hard to figure out what is going on there
> 
> 
> 
> ...


 
  I am clueless to what can be causing this; it's a bit way too technical to me. But I can still confirm that what I've heard is still occuring
  Quote: 





grokit said:


> The Bifrost reportedly clicks when the sampling rate changes.


 
  Yes this is true


----------



## AKG240mkII

Quote: 





drez said:


> I think you misunderstood me, I said I prefer to use a small buffer for reasons"other than input delay."
> 
> There most definitely is such a thing as latency and it is there in varying amounts at every stage of the computer setup.  You want to to input a command to a music player, there is latency, to access a hard disk, there is latency, you have different bus speeds, different speeds of data flow, and on top of this data does not usually arrive in a smooth manner so you need buffers at strategic points to ensure there is a constant flow of data and no dropouts.  If you have a problem where the latency is inconsistent (very typical in Windows machines) you need a larger buffer, or on the other hand you can use techniques like ram disk etc to ensure a smoother flow of data and therefore not need such a large buffer.  You can also not use a ram disk at all and just use a larger size buffer, but I find that this does not sound as good to my ears.  Most music software do not load the entire file into ram, they instead load a number of samples ahead of time thus use a buffer.  Audio data coming out of a USB port does not have consistent timing, which is why timing correction mechanisms are needed at the USB receiver, maybe even another buffered control mechanism.  IMO none of these systems are perfect at fixing timing issues, whether this is audible is another matter.
> 
> The simplistic view is that you can just use a large buffer at any stage and you will get perfect results, but in my opinion this is not the case, as in I believe the buffer size and nature affects the sound quality.  You may not hear any differences from these settings and this is fine.  Even if I could provide evidence for any of my opinions I do not think it would be in anyone's interest.  I could for argument's sake throw a million ferrite beads on a USB cable, prove I can hear a difference with DBT and then say a million ferrite beads sounds better, but still not be contributing anything useful.  What I mean to say is that audio is so inherently subjective that even if a difference can be heard, people will not agree on whether there is an improvement.  IMO If you are really interested in something you need to do your own research and not rely on extrapolation and prediction from other peoples research, and not mistake one (or more) negative result/s for a universal truth in circumstances outside the scope of the test setup.  If you don't worry about subtle differences in sound quality then you could just not do the testing and direct your efforts elsewhere.


 
   
   
  Quote: 





> Even if I could provide evidence for any of my opinions I do not think it would be in anyone's interest.


 
  Please do !
  I would REALLY like to hear why there is such a thing as 'latency' during *playback* of a digital file !
   
  Or move this to one of the voodoo-allowed threads 
   
  Latency - Relative TO WHAT *during playback ?*
  Either your soundcard/DAC - call it what the hell you want - plays music.. Or it doesn't !
   
   
   
  Quote: 





> IMO If you are really interested in something you need to do your own research and not rely on extrapolation and prediction from other peoples research, and not mistake one (or more) negative result/s for a universal truth in circumstances outside the scope of the test setup.  If you don't worry about subtle differences in sound quality then you could just not do the testing and direct your efforts elsewhere.


 
  Yeah, the engineers don't know **** and science even less, right ?
  All their megabucks analyzers are wrong, because they don't use Black Gates and you cant roll the op-amps ?
   
  I worry about the subtle differences between a 1962 and a 20XX Fender-guitar -
  I don't worry about playback-latency because there is no such thing !
   
  SERIOUSLY !
  This thread is bollocks, please move it to one of the many non-science threads !
  USB-cable and sound-quality ?
  LATENCY during playback ??
  VOODOO-HIFI BOLLOCKS IS WHAT THIS IS !


----------



## bigshot

The reason that latency is an issue for recording is that you are laying down tracks. You listen to the playback from the last track you cut as you play the one you're recording. Latency can screw up musicians' performances because if their performance is being filtered in real time, a delay caused by an overloaded processor can totally mess up them monitoring themselves, and it can cause sync issues with the track they're laying down. You can't record with latency.
   
  But for playback, you only have one track, and if there's a microsecond delay in playback it doesn't affect anything. It doesn't have to sync to anything else. Latency isn't an issue for playback. Buffer underruns are the problem there. That results in skips and clicks.


----------



## Griploc

I am an audio engineer and music producer and i back this quote by big shot. When dsp is being used from your computer big or small amounts of latency will occur. Audio plug ins are usually the culprit for this, but if you have a really low buffer setting that may fix the problem when recording takes. The larger the buffer the more latency occurs.


----------



## joeyjojo

Quote: 





chewy4 said:


> How could an increased buffer size possibly hurt sound quality?


 
   
  I'd like to know this as well. Head-fi rumour or truth?


----------



## liamstrain

chewy4 said:


> How could an increased buffer size possibly hurt sound quality?


 

 On playback? It cannot. If anything, it helps since it has time to compensate for data transmission errors.


----------



## mikeaj

Set the buffer to 20 years.
   
  When you come back and listen, your hearing might be worse!


----------



## Stommager

What an interesting thread! 
   
  I find myself amazed by the number of different concepts being presented here.
  Personally I agree with the ones that say that USB can't have any influence on sound quality. For those who thing different I have this little experiment:
   
  - prepare a wave file of Your favorite song and an pan drive
  - take the first cable (the expensive one, for example) and connect Your pen drive via it (it might require additional connector)
  - make a copy of Your wave file into the pen drive
  - now connect the pen drive via the second, standard USB cable and make a second copy of Your wave file
  - now connect Your pen drive directly to Your PC and compare the two files bit-wise
  - keep repeating until You find any difference 
   
  Now someone might ask: what does it have to do with DAC and audio playback?
  Well, actually everything, because that's exactly what DAC's USB component does: makes a copy of Your audio data and stores it in a memory.
  The only read difference is that it does not copy the entire track at once, but rather a small portion at a time. Once this portion in written into the DAC's memory it is read sequentially and fed into the actual DAC chip. Once we get near the end of the portion being played, another one gets copied over USB. This way we make just another copy of Your audio data, only the destination memory and the copying procedure is slightly different. How can anyone expect that a decent DAC cannot do what any no name pen drive can?
   
  For me it is really that simple. If the portions of Your audio data arrives on time (in normal circumstances they always do) there is nothing within USB cable that can affect the sound. I think It is very important to understand that data transfer rate inside USB cable has nothing to do with the DAC's clock. Data is being sent in bursts and then for considerably long time nothing happens. DAC's memory (the buffer) is being read sequentially, sample by sample according to DAC's internal clock. My E-MU gives a great example. When I use USB as an input the diode always indicates that the device runs on it's internal clock. In a properly designed DAC no jitter nor any typical level of electric noise can affect analog audio signal, because they are being separated by the buffer and I'm sure that, as well as any pen drive, the buffer gets perfect copy of Your data. Try copying some documents onto Your pen drive via USB cable and see if You can detect any typing errors being introduced due to the jitter or electric fluctuations.


----------



## drez

Quote: 





chewy4 said:


> How could an increased buffer size possibly hurt sound quality?


 
   
  I have no idea how it could, from what I understand I would not expect it to make a difference, and in my experience it does not make a significant difference.  As I do not have enough understanding of the inner workings of computer audio software, drivers etc. I can't speculate on why buffer size could make a difference.
   
  On the other hand I find I prefer using a smaller buffer size, and with a software like JPlay I find using too large buffer can undo some of the benefit.  The changes I think I am hearing however are very small, even with large changes in software buffer size, for example in the record I am listening to now the backing violins are _a little_ more vague with a buffer size of 1 second compared to 0.1 second.  Put it this way I do not like my chances of telling the difference in a blind test.
   
  For all sensible intents and purposes you probably don't have to worry about it.  If you are chasing that last 1-2% of performance then maybe it might be worthwhile comparing.  It is free to test after all.
   
  But the only way I can see anything feeding an asynchronous USB DAC making a difference beyond dropouts is by affecting the buffer management.  If it were a case of the stream either working or not working ie the buffer at the DAC either working or not working then I can't see how anything on the computer or USB cables etc could make a difference, but I do not think this is the case.  Plenty of variables from bitstream size (24 or 16 bit) to CPU scheduler settings seem to make a difference in my experience.  If you haven't noticed anything similar it is probably a lot to swallow.
   
  Yes this is truly getting into magical audiophool terriroty here so I am probably trying to dig my way out of a hole here...  Probably getting away from discussing USB cables also...


----------



## bigshot

"There's no reason that it would make any difference, but I hear a tiny bit of vagueness in the backing violins... I'm sure it would disappear in blind testing."

You've got a textbook example of expectation bias there. It's a useful thing to think about and learn from when it's that clear cut. What other areas may expectation bias be creeping into your analysis of sound quality? Use what you're experiencing here to test other things you believe you hear.

Good sound isn't about perfecting the last 1% or 2%... That's the realm where expectation bias rules the roost. Good sound is about driving the bugs out of the 98% or 99%. It is a LOT harder than it seems to do that. It's so hard, a lot of people don't even bother to address it. They put their faith in high price tags and fancy sales literature and piddle away their energy worrying about things that just don't matter.


----------



## Clarkmc2

bigshot said:


> Good sound isn't about perfecting the last 1% or 2%... That's the realm where expectation bias rules the roost. Good sound is about driving the bugs out of the 98% or 99%. It is a LOT harder than it seems to do that. It's so hard, a lot of people don't even bother to address it. They put their faith in high price tags and fancy sales literature and piddle away their energy worrying about things that just don't matter.




Using this as a litmus test, I have been able to ignore nearly all the posts on audio forums for years. It has also directed my personal pursuit of improving my own systems.


----------



## ultrabike

Quote: 





stommager said:


> What an interesting thread!
> 
> I find myself amazed by the number of different concepts being presented here.
> Personally I agree with the ones that say that USB can't have any influence on sound quality. For those who thing different I have this little experiment:
> ...


 
   
  That wouldn't be fair though. A file copy would more than likely be a "Bulk" transfer, while most time sensitive devices (DACs) use the higher priority "Isochronous" trasfer (usually Adaptive mode):
   
http://www.beyondlogic.org/usbnutshell/usb4.shtml
   
  My undestanding is that "Bulk" uses ACKs to synch transfers, while Adaptive "Isochronous" requires clock recovery since the slave device (DAC) has no control over the rate at which data arrives to it.
   
  All that said, I don't think the jitter coupled through the source clock is an issue as long as the receiver in the slave devices does a good job at mittigating it. I believe Stereophile publishes jitter rejection of the DACs they review. Some manufacturers may publish their specs also...
   
  Note that this may only be an issue with poorly implemented external DACs. If using a Sansa Zip/Clip, iPOD/iPAD internal DAC, or such, where data is stored in memory (though USB "Bulk" transfer), then this source coupled jitter deal becomes a non-issue AFAIK.


----------



## grokit

Quote: 





ultrabike said:


> Quote:
> 
> 
> 
> ...


 
   
   
  That's what I was thinking, that *Stommager* was describing how an asynchronous DAC works. In an adaptive DAC, we are relying on the computer's internal clock for better or worse. The bits may get there on time, but not necessarily _in time. _IMO there's a difference, and that's where jitter issues can come into play.


----------



## dvw

Quote: 





grokit said:


> That's what I was thinking, that *Stommager* was describing how an asynchronous DAC works. In an adaptive DAC, we are relying on the computer's internal clock for better or worse. The bits may get there on time, but not necessarily _in time. _IMO there's a difference, and that's where jitter issues can come into play.


 
  You are talking about packet jitter rather than timing jitter I assumed. With packet jitter, the difference can be solved by the buffer unless the latency is extremely large, then you might have buffer overrun or underrun. In either case, this will result in skipped sound or pop corn noise.


----------



## proton007

Quote: 





liamstrain said:


> On playback? It cannot. If anything, it helps since it has time to compensate for data transmission errors.


 
   
  Exactly.
   
  I still fail to understand what all the previous 5 pages have to do with playback. Digital audio has clear, easy to hear issues if there are any, or none at all.
  Its been designed in a way that if it breaks, it'll produce obvious issues. Otherwise you won't notice anything.


----------



## proton007

Quote: 





bigshot said:


> Good sound isn't about perfecting the last 1% or 2%... That's the realm where expectation bias rules the roost. Good sound is about driving the bugs out of the 98% or 99%. It is a LOT harder than it seems to do that. It's so hard, a lot of people don't even bother to address it. They put their faith in high price tags and fancy sales literature and piddle away their energy worrying about things that just don't matter.


 
   
  Another aspect is whether that last 1-2% is worth caring about. You can think about using 128 bit precision to get as close to analog as possible and reduce quantization errors, but if it doesn't make a dime's worth of a difference, its no use.
  This is the whole gist of design. Everything is designed to a specification. And the specification is made on the basis of an established phenomenon.
  I mean, given the money and time, someone can definitely come up with this, with a million dollar price tag, but if it doesn't matter, it doesn't matter.
   
  Another common example would be the iPhone retina display. Would you notice if I make it twice the resolution at the same size? The answer is no, and hence its not worth the extra processing and graphics power it would require.


----------



## bigshot

proton007 said:


> You can think about using 128 bit precision to get as close to analog as possible and reduce quantization errors, but if it doesn't make a dime's worth of a difference, its no use.




To heck with 128 bit. I can get closer to analogue by hitting it in the right spot with a ball peen hammer.


----------



## drez

Quote: 





proton007 said:


> Another aspect is whether that last 1-2% is worth caring about. You can think about using 128 bit precision to get as close to analog as possible and reduce quantization errors, but if it doesn't make a dime's worth of a difference, its no use.
> This is the whole gist of design. Everything is designed to a specification. And the specification is made on the basis of an established phenomenon.
> I mean, given the money and time, someone can definitely come up with this, with a million dollar price tag, but if it doesn't matter, it doesn't matter.
> 
> Another common example would be the iPhone retina display. Would you notice if I make it twice the resolution at the same size? The answer is no, and hence its not worth the extra processing and graphics power it would require.


 
   
  This is a good point, along with the one bigshot made - if something is so insubstantial that it can't be reliably discerned then it probably isn't worth spending money on, especially when there are other more tangible things competing for the same money.  With my equipment I would say that USB cables and software buffer size would both fall under this category, it is a strain to tell the difference.  Other changes I have mentioned like bit depth and processor scheduling are a little more obvious from memory, but I would really need to test them again to quantify how much of a difference they make, and these variables are relatively easy to toggle.  I *think* I would be able to DBT bit depth, I would just need to come up with a methodology, and again this is not directly related to USB cables.  I will have to get back to you on that one.
   
  The reason I pursue some of these things is because 1-2% is not much by itself, but add up several such minor changes and soon enough there may be something more significant like a 5-10% difference, plus playing around with these settings is free so no harm is done to the wallet.  Unfortunately I have tried some audiophool tweaks that are very much not free and also very much rubbish components that made the sound worse.  
   
  I try to warn people about these as much as possible, but the whole subjectivity thing means many people hear an improvement when the change is actually negative - it is easier after all to create an audible difference by making something worse than it is to make an audible difference by making something better, I think a lot of audiophile companies know this and exploit the subjectivity of audiophiles.  Considering this it is probably wiser to stay away from audiophile tweaks, especially really dodgy sounding, tenuous and yet also expensive tweaks.


----------



## ultrabike

Quote: 





dvw said:


> You are talking about packet jitter rather than timing jitter I assumed. With packet jitter, the difference can be solved by the buffer unless the latency is extremely large, then you might have buffer overrun or underrun. In either case, this will result in skipped sound or pop corn noise.


 
   
  Yes. Buffer underrun is probably a more common gross issue due to PC neglecting it's USB duties.
   
  However, in the minutiae aspect of audio thingies, if the DAC clock is somehow derived from the source (PC) then some likely small amount of timing jitter could make it's way to the DAC buffer reads... Likely this jitter is measurable, but perhaps *inaudible*. Some examples of DAC jitter characterization:
   
http://www.stereophile.com/content/abbingdon-music-research-dp-777-da-processor-measurements (fig. 24)
http://www.stereophile.com/content/bel-canto-eone-dac35vb-da-converter-measurements (fig. 9)
http://www.stereophile.com/content/rega-dac-da-processor-measurements (fig.15)
   
  A very clean one using asynchronous mode:
http://www.stereophile.com/content/halide-design-dac-hd-da-converter-measurements (fig. 10)
   
  I have a Total BitHead DAC/Amp which seems to suffer from jitter a little more than the previous examples (probably since it's an older design):
http://www.stereophile.com/content/headroom-total-bithead-headphone-amplifier-measurements (fig. 12)
  I can't say the jitter was clearly audible. Maybe it would manifest itself as some sort of distortion... I could see there might be better DAC/Amps out there in terms of measurable performance at the very least.
   
  To me, however, the long pole in the tent is the headphone itself, and USB cables are next to non-issue.


----------



## proton007

By now I feel this thread has run circles a few times already....what do you guys think?


----------



## drez

Quote: 





proton007 said:


> By now I feel this thread has run circles a few times already....what do you guys think?


 
   
  I probably am [running circles] anyway
	

	
	
		
		

		
			





  It's good exercise right?


----------



## Clarkmc2

proton007 said:


> By now I feel this thread has run circles a few times already....what do you guys think?




The topic was most likely very easily answered in relation to practicality - no - but the inevitable theoretical discusions amused some contributors. As a self examination tool, it could have its uses. If all the digression from no or yes was fun, one has to admit that the hobby is personally as much about gear as it is about music. Personally, I'd rather spend my non listening time talking about music than whether small tweaks matter or not. That means spending this much time on equipment forums is in my case a character flaw and does not say good things about my allocation of my free time. At least I learned that from this thread.


----------



## ultrabike

Quote: 





proton007 said:


> By now I feel this thread has run circles a few times already....what do you guys think?


 
   
  LOL! It has indeed.... But I guess...


----------



## bigshot

drez said:


> The reason I pursue some of these things is because 1-2% is not much by itself, but add up several such minor changes and soon enough there may be something more significant like a 5-10% difference,




For some reason, few people understand my point. I'm not saying that 1 or 2% is too small to bother with. I'm saying that too many people who worry about small issues *haven't even dealt with the big issues yet*.

It's easy to buy another cable. It isn't easy to achieve a flat frquency response. I am quite sure that the number of people around here employing precise equalization is very small. Also, what's the point of worrying about the "sound signature" of a simple wire when you're listening to hot mastered music with loads of added distortion effects? Maybe better recorded music would help. How many people looking to upgrade the sound of their $800 headphones make the obvious upgrade- to speakers?

These are all things that improve sound to a degree that you don't need measurements or double blind testing to discern. There is absolutely no reason to worry about the little stuff until you've dealt with these issues. The most expensive cabling in the world won't make the Red Hot Chili Peppers' miserably engineered albums sound good. And modding your amp won't help if you haven't EQed to flatten out the bass hump and high end spike in your cans. And even if you've taken care of all that and have a great headphone rig and well engineered music, a good speaker system will blow the pants off it when it comes to soundstage and presence.

Just swapping cables looking for placebo improvements is a complete waste of time. Jitter is inaudible. bringing it up over and over "for the sake of completeness" only misleads people into thinking it matters. it doesn't. not even a little bit. Great sound is about the big things, not the tiny ones.


----------



## dvw

Quote: 





bigshot said:


> For some reason, few people understand my point. I'm not saying that 1 or 2% is too small to bother with. I'm saying that too many people who worry about small issues *haven't even dealt with the big issues yet*.
> It's easy to buy another cable. It isn't easy to achieve a flat frquency response. I am quite sure that the number of people around here employing precise equalization is very small. Also, what's the point of worrying about the "sound signature" of a simple wire when you're listening to hot mastered music with loads of added distortion effects? Maybe better recorded music would help. How many people looking to upgrade the sound of their $800 headphones make the obvious upgrade- to speakers?
> These are all things that improve sound to a degree that you don't need measurements or double blind testing to discern. There is absolutely no reason to worry about the little stuff until you've dealt with these issues. The most expensive cabling in the world won't make the Red Hot Chili Peppers' miserably engineered albums sound good. And modding your amp won't help if you haven't EQed to flatten out the bass hump and high end spike in your cans. And even if you've taken care of all that and have a great headphone rig and well engineered music, a good speaker system will blow the pants off it when it comes to soundstage and presence.
> Just swapping cables looking for placebo improvements is a complete waste of time. Jitter is inaudible. bringing it up over and over "for the sake of completeness" only misleads people into thinking it matters. it doesn't. not even a little bit. Great sound is about the big things, not the tiny ones.


 
  My impression of the last 1 to 2 % improvement quoted by some people actually means if I spent more money, I can reach the pinnacle of "audiophiledom". This has absolutely no relationship to quality. The key qualifier is the color. How can there be color in a 100% fidelity system? By definition, 100% fidelity systems will sound exactly the same. This fact also contradicted the audiophile notion that everything has a signature sound even cable and they sound all different. It's like people are making their own instrument instead of listening to one.
   
  IMO, the last 1 or 2% is not achievable. I have heard some awesome systems but there is none that I will mistake for a live performance. Perhaps it's in the recording or the setup. Or I may need to do a live DBT. Any way, I can always tell if it's live or if it's Memorex.


----------



## ultrabike

Agreed.
   
  Also, to me the closest to live performances has been binaural recordings (through headphones)... Like you said, certain improvements may require setup/recording infrastructure changes. Then there is the loudness wars.


----------



## drez

Quote: 





bigshot said:


> For some reason, few people understand my point. I'm not saying that 1 or 2% is too small to bother with. I'm saying that too many people who worry about small issues *haven't even dealt with the big issues yet*.
> It's easy to buy another cable. It isn't easy to achieve a flat frquency response. I am quite sure that the number of people around here employing precise equalization is very small. Also, what's the point of worrying about the "sound signature" of a simple wire when you're listening to hot mastered music with loads of added distortion effects? Maybe better recorded music would help. How many people looking to upgrade the sound of their $800 headphones make the obvious upgrade- to speakers?
> These are all things that improve sound to a degree that you don't need measurements or double blind testing to discern. There is absolutely no reason to worry about the little stuff until you've dealt with these issues. The most expensive cabling in the world won't make the Red Hot Chili Peppers' miserably engineered albums sound good. And modding your amp won't help if you haven't EQed to flatten out the bass hump and high end spike in your cans. And even if you've taken care of all that and have a great headphone rig and well engineered music, a good speaker system will blow the pants off it when it comes to soundstage and presence.
> Just swapping cables looking for placebo improvements is a complete waste of time. Jitter is inaudible. bringing it up over and over "for the sake of completeness" only misleads people into thinking it matters. it doesn't. not even a little bit. Great sound is about the big things, not the tiny ones.


 
   
  Very good point, hard to argue with.
   
  Quote: 





dvw said:


> My impression of the last 1 to 2 % improvement quoted by some people actually means if I spent more money, I can reach the pinnacle of "audiophiledom". This has absolutely no relationship to quality. The key qualifier is the color. How can there be color in a 100% fidelity system? By definition, 100% fidelity systems will sound exactly the same. This fact also contradicted the audiophile notion that everything has a signature sound even cable and they sound all different. It's like people are making their own instrument instead of listening to one.
> 
> IMO, the last 1 or 2% is not achievable. I have heard some awesome systems but there is none that I will mistake for a live performance. Perhaps it's in the recording or the setup. Or I may need to do a live DBT. Any way, I can always tell if it's live or if it's Memorex.


 
   
  I think the "sound signature" or coloration is often seen as a means of covering up another flaw in a system or bad recordings etc.  Some people like a bit of bloom in the sound, and strangely some digital audiophile tweaks IMO can provide this, but it is not actually higher fidelity from an objective perspective.  Some forms of distortion seem to be more bothersome than others, even at levels which would not otherwise be considered significant.  A couple of videos that are mildly relevant to these concepts:


----------



## Hi Rez

Borrowed a very expensive USB cable this past week to try in my big rig at home.  Source is a Mac Mini > Pure Music (Integer mode) > Ayre QB9.  I had been using the cable that came with the QB9.  As much as I hate to admit it was a huge step up in performance - much greater transparency that allowed much more musical nuance to come through.  Using the expensive cable, playing Emmylou Harris's Boulder to Birmingham (Producer's Cut 24/96), her emotion comes thru in the music and hits hard.  And the QB9 runs asynchronous transfer mode, so you wouldn't think USB cables should change the presentation.
   
  Of course all good things must come to an end - cable has to be returned tomorrow.  Took it out the system and put in the old.  Decided to play Boulder to Birmingham one more time.  All that sense of emotion was gone....
   
  Before you flame.  Went upstairs to talk to my wife who was in bed in another room.  First thing she said:  Something changed - the song didn't sound nearly as good the last time you played it.  She didn't even know I had a borrowed USB cable in the system.  Wasn't a DBT, but it certainly was a blind test....


----------



## liamstrain

Interesting anecdote - not much to actually work with, and way too many uncontrolled, and unknown variables to be useful, but interesting nonetheless. 
   
  Welcome to head-fi.


----------



## grokit

I believe you!


----------



## chewy4

Quote: 





hi rez said:


> Borrowed a very expensive USB cable this past week to try in my big rig at home.  Source is a Mac Mini > Pure Music (Integer mode) > Ayre QB9.  I had been using the cable that came with the QB9.  As much as I hate to admit it was a huge step up in performance - much greater transparency that allowed much more musical nuance to come through.  Using the expensive cable, playing Emmylou Harris's Boulder to Birmingham (Producer's Cut 24/96), her emotion comes thru in the music and hits hard.  And the QB9 runs asynchronous transfer mode, so you wouldn't think USB cables should change the presentation.
> 
> Of course all good things must come to an end - cable has to be returned tomorrow.  Took it out the system and put in the old.  Decided to play Boulder to Birmingham one more time.  All that sense of emotion was gone....
> 
> Before you flame.  Went upstairs to talk to my wife who was in bed in another room.  First thing she said:  Something changed - the song didn't sound nearly as good the last time you played it.  She didn't even know I had a borrowed USB cable in the system.  Wasn't a DBT, but it certainly was a blind test....


 
  Don't you think that the fact that the emotional response changed might have something to do with your own emotions?
   
  Interesting that your wife noticed a difference, especially since she was in another room in a separate floor in the house. Did you ask her if something changed or did she just say it out of the blue?


----------



## Hi Rez

Quote: 





chewy4 said:


> Don't you think that the fact that the emotional response changed might have something to do with your own emotions?
> 
> Interesting that your wife noticed a difference, especially since she was in another room in a separate floor in the house. Did you ask her if something changed or did she just say it out of the blue?


 
  That is the part that surprised me - she just said it out of the blue.
   
  I don't believe my emotions had much to do with it.  Actual words are a only a small part of verbal communication - tone and inflection of voice provides much more information.  The words can say one thing, and the tone and inflection something completely different. With the borrowed cable, fine details like the quavering in her voice came thru much more clearly, and the music had a larger impact because of it.


----------



## chewy4

Quote: 





hi rez said:


> That is the part that surprised me - she just said it out of the blue.
> 
> I don't believe my emotions had much to do with it.  Actual words are a only a small part of verbal communication - tone and inflection of voice provides much more information.  The words can say one thing, and the tone and inflection something completely different. With the borrowed cable, fine details like the quavering in her voice came thru much more clearly, and the music had a larger impact because of it.


 
  And those fine details are something that can be heard on a separate floor of a house?


----------



## liamstrain

chewy4 said:


> And those fine details are something that can be heard on a separate floor of a house?


 
   
  Indeed. While doing something else, moving well off axis from the speakers, etc. 
   
  I'm not saying there wasn't an audible difference. But we don't have enough here to go on to ascribe any part of it to the cable, much less understand what the difference was and the mechanism for creating it.


----------



## ultrabike

Actually, headphone positional variation has been shown to affect the high frequencies... Probably more so than the cable...


----------



## edn4x4

That stream of binary data finding it's way is all about the journey, the destination and perhaps most important is the source.
  In this case the cable provides the journey - that's the way I look at it.  If you have a good source and it leads you to your destination you should be happy!
  I know this is HF and we are always on our journey - enjoy.
   
  Remember this:
  There are 10 kinds of people in the world. 
  Those that understand binary and those who don't.


----------



## Griploc

Okay, do i apoligize for dipping out of thr topic for a couple months but i wanted to burn in all my recent cable upgrades. From headphone cable to usb canle to power cable torven mic cable. So i will say one thing here. I will do my dbt with the usb next weekend to be precise. I wont give you my opinion of what i already think of the usb until i have my students swap them in and out ad well as see if my students can hear am audible difference


----------



## Griploc

Again i am going to be testing the stefan audio art USB, the Apogee USB, and lastly a Regular out of store usb cable


----------



## Griploc

My listening will be done through AKG K702 headphones with SAA endorphin headphone cable upgrade to my Apogee Symphony IO interface(vibration controlled with mapleshade 4inch platform using micropoint brass heavy weight hats and micropoint brass heavy weight footers and based on rubber and cork) using a SAA endorphin power cable upgrade. The USB will be connected from the Apogee Symphony IO to my iMac computer listening directly into a Pro tools 9 session


----------



## ultrabike

Some preliminary questions...
   
  How do you plan to rule out headphone frequency response positional variations?
  Are you going to evaluate and/or guarantee the integrity of the signal before it arrives to the usb cable in terms of noise, jitter, frequency response .... and so on?
  Is the connector of the iMac in "good" condition (mechanically integrity, no oxidation, and so on)?
  Are the connectors of all cables in "good" condition (mechanical integrity, no oxidation, and so on) and are they all USB 2.0 standards compliant?
  Are you going to conduct some basic frequency response and/or noise rejection characterization of these cables?


----------



## Griploc

The signal chain of each component is at a high standard. All cables and vibration control i have specified are of ultra high end quality and burned in for over 150 hours. I will conduct white and pink noise signal testing prior to the dbt as well to ensure frequencies are as flat as they will be according to the headphones i will be using. All contacts have been extensively treated and deoxified by James, owner of SAA, former tech engineer of Senheisser.


----------



## Griploc

I will also put up a link of a song rendered with and without the upgaded USB to show the head-fi community so they can judge to hear if an audible difference is there


----------



## Griploc

My thoughts towards cables, connector contacts, components, and source has been flipped upside down over the past couple years due to delving into the realm of hi end professional recording and reference monitoring. I have over 10 years of engineering experience and 5 years professional.


----------



## mikeaj

griploc said:


> I will also put up a link of a song rendered with and without the upgaded USB to show the head-fi community so they can judge to hear if an audible difference is there




If you can include the original too, that would be great. Recording multiple times (well, 2 would be nice at least) with each cable would be helpful as well.


----------



## ultrabike

Quote: 





mikeaj said:


> If you can include the original too, that would be great. Recording multiple times (well, 2 would be nice at least) with each cable would be helpful as well.


 
  +1


----------



## Griploc

Original, by that how do you mean? If I were to record something from scratch technically that would be the original.
   
  I will record the same song twice from the ground up using each USB cable then bounce it down from protools with each USB.
   
  My vocal microphone signal chain is a U87 ai connected to a SAA E-Series Mic cable (using a Cardas custom cable body with alchem XLR connectors)
  I will use SW and or my Triton Extreme Keyboard for instrumentation (cabling is Mogami 2534 neglex gold with the Neutrik ends off because they actually yield frequency content and dynamic range) 
   
  My Triton Extreme keyboard and iMac are both suspended from the desk using 1" by 2" rubber cork blocks (4 each, one on each corner) to reduce vibrations and thus cleaner sound.


----------



## liamstrain

> If I were to record something from scratch technically that would be the original.
> 
> I will record the same song twice from the ground up using each USB cable then bounce it down from protools with each USB.


 
   
   
  Are you talking about providing multiple performances recorded with different cables in the chain?
   
  I don't think that will provide much useful data for us here. 
   
  Better for these purposes to use the same source file or recording, and then process it through. Then you can compare that source against the processed files to look for any influence the USB cable had. If you are providing multiple performances, there are too many variables to compare.


----------



## Griploc

I will bring a stereo paired song i recorded mixed and mastered into protools and render it down with the three different USB cables. I will include the original song as the reference.


----------



## ultrabike

Quote: 





griploc said:


> I will bring a stereo paired song i recorded mixed and mastered into protools and render it down with the three different USB cables. I will include the original song as the reference.


 
  I suggest you do what Mikeaj was recommending: record at *least twice with the same cable*. Make sure the recordings are *not *different when using the same cable.


----------



## Griploc

By recording do you mean record a audio signal through the usb cables? That wont be possible because my usb cables signal path is only connected from my audio interface to my computer. If i were to render or bounce a audio file down that was previously recorded than that would be doable.


----------



## ultrabike

Quote: 





griploc said:


> By recording do you mean record a audio signal through the usb cables? That wont be possible because my usb cables signal path is only connected from my audio interface to my computer. If i were to render or bounce a audio file down that was previously recorded than that would be doable.


 
  I'm not a audio engineer and I'm still learning, so don't know much about what it's meant by render or bounce an audio file down.
   
  But I guess if you mean that you will send some kind of digital signal from point A to point B for each cable, then you might as well do it at least twice for each cable. Doing so should include unplugging and plugging. In other words, threat the repeat cable test as if you were testing another cable.


----------



## Griploc

By render or bouncing down i mean having multiple tracks on a session 'rendered' into one stereo paired audio file


----------



## Griploc

Rendering the session will be converted through my interface and passed through my usb cables into my computer


----------



## nick_charles

Quote: 





griploc said:


> Rendering the session will be converted through my interface and passed through my usb cables into my computer


 
   
  You've fed us some information in small bites. It would be better if you could summarize your protocol as follows
   
  1. What is the fixed value that we start with (it must be verifiaby and exactly the same for all conditions) for instance the source such as a source file in a given format played back on a device
  2. What is the role of the independent variable (i.e cable) 
  3. How does the cable interact with the fixed value i.e does it connect between the source and the input of a PC
  4. What happens next? Is the transmitted signal recorded using some software - how do you account for random variation between multiple recordings of the same signal. When you digitally capture an analog signal you get variation from trial to trial. With a digital to digital capture this is less likely but you still need to make sure you know how much random variation there is. In my cable trials I recorded signals from each cable 10 times and could average out variation. I'd recommend a similar approach. This also involves extremely careful cropping and trimming of recorded samples. 
  5 Assuming there are no big random variations how will you measure the differences between the two conditions.
  6. If you are going to DBT samples I suggest no less than 15 trials
  7. Will you be posting short (fair use ) samples for others to evaluate ?
   
  The overarching principle is that only one variable is changed at a time and all other variables remain the same, easier said than done....


----------



## robilmc

Getting to this thread pretty late with my own anecdote. Been some interesting reading!
   
  Got a pair of HifiMan HE-400s for Christmas and immediately began hunting up amps and DACs. Landed on the Schitt Magni amp and Modi DAC. Jason Stoddard was great about answering questions and not trying to sell me stuff I didn't need. Very appreciative.
   
  About halfway through this thread I said "Screw it...I wonder what a manufacturer thinks about USB cables?"  This is what he said:
   
  "You should use a true USB 2.0 rated cable. Other than that, it doesn't matter, as far as we're concerned--except that expensive audiophile cables are usually 100% garbage, and cause problems (dropouts, garbled audio, etc) with USB input."
   
  Good enough for Jason, good enough for me.
   
  Thanks for the great read!


----------



## p a t r i c k

Quote: 





robilmc said:


> Getting to this thread pretty late with my own anecdote. Been some interesting reading!
> 
> Got a pair of HifiMan HE-400s for Christmas and immediately began hunting up amps and DACs. Landed on the Schitt Magni amp and Modi DAC. Jason Stoddard was great about answering questions and not trying to sell me stuff I didn't need. Very appreciative.
> 
> ...


 
   
  I'm hugely impressed by Jason Stoddard.


----------



## Mambosenior

Yep! No Schitt.


----------



## aivar1988

i have had TWO dh labs silver sonic 5m usb cables, both of them does not work correctly, lots of cracks and pops all over the music.... all fine with my 5m supra usb cable that is 5 times cheaper then dh labs cable. any ideas what could be wrong with dh labs cables ?  dh labs are silver coated, supra is tin coated copper.


----------



## chewy4

Quote: 





aivar1988 said:


> i have had TWO dh labs silver sonic 5m usb cables, both of them does not work correctly, lots of cracks and pops all over the music.... all fine with my 5m supra usb cable that is 5 times cheaper then dh labs cable. any ideas what could be wrong with dh labs cables ?  dh labs are silver coated, supra is tin coated copper.


 
  I would say either the cable doesn't meet USB standards, or isn't exactly 5m and is a little bit longer(maximum length is 5m).


----------



## drez

Quote: 





chewy4 said:


> Quote:
> 
> 
> 
> ...


 
   
  Probably true - if the cable packaging doesn't have USB logo they probably havent passed testing/certification to meet the USB spec.  Pretty odd though as I have hacked up many USB cables, even turned a SATA cable into USB and it worked (not well, but they worked without glitches or dropouts).  Hell even some really goofy audiophile cables can still work in some cases (I don't really want to name names).  Must be some bad mojo going on in those cables.


----------



## aivar1988

Quote: 





drez said:


> Probably true - if the cable packaging doesn't have USB logo they probably havent passed testing/certification to meet the USB spec.  Pretty odd though as I have hacked up many USB cables, even turned a SATA cable into USB and it worked (not well, but they worked without glitches or dropouts).  Hell even some really goofy audiophile cables can still work in some cases (I don't really want to name names).  Must be some bad mojo going on in those cables.


 
  im tired reading does usb cable make any diffrences or not.  wanted to test it out myself , is there or can i hear any differences between very cheap and a little higher priced "audiophile" usb cables, higher priced cable - dh labs usb cable is also silver coated while other one - supra usb cable is tin coated copper ... but as it turns out dh labs doesnt work at all like one usb cable should work  btw lenght was exaclty 5m so must be some other problem. but i already got refund. i have no interest to get third broken cable from dh labs so my testing is over for this time


----------



## drez

I think seeing as 5metres is already pushing the USB spec it will accentuate any flaws in the cable. All my hacked together cables were really short so any deficiencies didn't affect performance in an obvious way like dropout, glitch etc.


----------



## liamstrain

Could be bad/cold solder connections. 5m is also pretty long for USB.


----------



## aivar1988

i mean there is sound, music is playing but with crackling sound all over the music, 5m seems long yes but there are also 10-15m usb cables, why are they makeing them if it would not work ?


----------



## ultrabike

Quote: 





aivar1988 said:


> i mean there is sound, music is playing but with crackling sound all over the music, 5m seems long yes but there are also 10-15m usb cables, why are they makeing them if it would not work ?


 
   
  My understanding is that USB cable typical range is 3-16ft (5m). However, there are USB extenders which may be active:
   
http://www.monoprice.com/products/product.asp?c_id=102&cp_id=10303&cs_id=1030312&p_id=7644&seq=1&format=2


----------



## xnor

How far away from a PC can I put a USB device?
  Answer: 





> With the maximum of 5 hubs connected with 5m cables and a 5m cable going to your full speed device, this will give you 30m of cable (see section 7.1.19 for details). With a low speed device, you will be able to get a range up to 27m, depending on how long the device's cable is. With a straightforward cable route, you will probably be able to reach out 25m or so from the PC.


----------



## Nemeske88

Soo good that I've found this thread!
  On an another forum there were an argument about USB cables used for interconnection between the PC and the outboard DAC.
  The topic was: is there any difference between a 99c printer USB cable and a snake-oil-horrendous-price one. The argument haven't finished yet.
  Recently read an IT-book that said the digital data consist of packages that have a values 0 or 1, transferred between two points. The only difference could be the clocking of these two components that can interfere.
  So really: how can be any difference between the cables? It maybe absorbs the noise coming from the PCs USB interface as it uses switching PSU?


----------



## bigshot

"Either it works or it doesn't" is a motto that applies to a lot of digital audio. If there is a problem, it's rarely a subtle thing. I think people try to carry over truisms from the analogue era where good sound meant dealing with layers and layers of slight imperfections. Digital is much more straightforward.


----------



## jaddie

Quote: 





bigshot said:


> "Either it works or it doesn't" is a motto that applies to a lot of digital audio. If there is a problem, it's rarely a subtle thing. I think people try to carry over truisms from the analogue era where good sound meant dealing with layers and layers of slight imperfections. Digital is much more straightforward.


 
  Agreed.  Kinda nice, though, isn't it?  Remember when you'd grab a fresh pancake of tape, only to discover it was from a different batch than you calibrated with, and you lost 2dB at the top end just by swapping tape batches?  Yup, all the time.  Or how about tweaking record head azimuth to the last gnat's eyebrow, only to discover the right channel was biased wrong, and you had now mis-adjusted the record head az because of it.  Yuck.  Or you wanted to intercut a take from the tail of a reel with one from the head, but your Ampex 350 had so much slip that the takes don't match in pitch.  
   
  All in all, we have nothing (literally) to worry about once a cable will do USB2 or USB3, we're pretty much happy campers.
   
  OK, sorry, all of that was just an analog vent and purge.


----------



## bigshot

I used to have to calibrate and set custom bias for each and every roll of three stripe mag I ran. I'd get halfway through a reel and check source against playback and notice that a glob of mag stripe came off and embedded itself on the heads. Fun!


----------



## robertsong

Quote: 





aivar1988 said:


> i have had TWO dh labs silver sonic 5m usb cables, both of them does not work correctly, lots of cracks and pops all over the music.... all fine with my 5m supra usb cable that is 5 times cheaper then dh labs cable. any ideas what could be wrong with dh labs cables ?  dh labs are silver coated, supra is tin coated copper.


 
   
   
  I don't know anything about DH cables, but I was very pleased with the 1.5 m Pangea AG cable that I had. Probably on par with the Kimber AG cable. It had less grain in the 5-10Khz region and smoother dynamics over the Lacie Flat cable.
   
  I have now upgraded to a Revelation Dual Conduit cable, and I'm stunned at the improvement. Everything said about this cable on the internet is true. Very significant upgrade.


----------



## leogodoy

Oh boy. Lemme grab some popcorn.


----------



## bigshot

I use the USB cables that came with my external hard drives. They work great with crystalline clarity and soundstage that is so deep, you can measure it in fathoms.


----------



## White Lotus

Quote: 





bigshot said:


> "Either it works or it doesn't" is a motto that applies to a lot of digital audio. If there is a problem, it's rarely a subtle thing. I think people try to carry over truisms from the analogue era where good sound meant dealing with layers and layers of slight imperfections. Digital is much more straightforward.


 

 +1 to this. I can't see any reason why a digital cable would (or _could_) change a "sound signature". 

 If the two devices can detect each other, then data will be transferred.


----------



## leogodoy

bigshot said:


> I use the USB cables that came with my external hard drives. They work great with crystalline clarity and soundstage that is so deep, you can measure it in fathoms.




But... But... The Revelation one costs 600 bucks. It HAS to be better, otherwise it would mean there are people who are not fully honest in the world, and you wouldn't want that, would you Bigshot?


----------



## Nemeske88

+1
   
  IMHO the amount of coffee one drunk a day can be more affective to the sound quality than any USB cable albeit I love fancy coating of some expensive digital cables. These are rather for pimping.


----------



## White Lotus

Quote: 





nemeske88 said:


> +1
> 
> amount of coffee one drunk a day can be more affective to the sound quality


 

 I use a pod system instead of a (real) coffee machine. I've found that it really opens up the detail of my DACs.


----------



## aivar1988

i hear pot " system " is very efficient to raise SQ too


----------



## robertsong

Quote: 





leogodoy said:


> But... But... The Revelation one costs 600 bucks. It HAS to be better, otherwise it would mean there are people who are not fully honest in the world, and you wouldn't want that, would you Bigshot?


 
   
   
  I would have to guess you have never heard a top quality cable, and never will so how can you possibly start an argument about it? My apologies to you for being so misinformed.


----------



## anetode

Quote: 





robertsong said:


> I would have to guess you have never heard a top quality cable, and never will so how can you possibly start an argument about it? My apologies to you for being so misinformed.


 

 I would have to guess that you haven't read and certainly haven't understood this thread, so how can you possibly start an argument in it? My apologies, dear sir, for your unfortunate state of misinformededness.


----------



## Lorspeaker




----------



## robertsong

Quote: 





anetode said:


> I would have to guess that you haven't read and certainly haven't understood this thread, so how can you possibly start an argument in it? My apologies, dear sir, for your unfortunate state of misinformededness.


 
   
   
  What??? _Of course_ I did not read the thread. Why would I? LOL
   
   
  What could I possibly be misinformed about? I have tried 6 different cables. Some differences were subtle, others were enormous.


----------



## robertsong

First post of the thread:
   
   
  Quote:


rudybagel said:


> Dare I put my toes into the water? I'm a physicist and audiophile (establish credibility!). I've been into living room system audiophilia for 20 years. This pc-audio is new to me and I'm just starting up. Now, about USB cables: I can hear a small difference between cables. If we assume the bits are transferred properly (and there is some debate  about that in USB-audio vs. USB-data), I think the issue is electromagnetic nosie getting through the circuits and into, in my case, the headphone amplier. All EM noise is immediately spread through an entire system, end-to end. Since at the end of the day, something is converted to analog to hear it, the cleaner the power and the better the shielding, the cleaner the final D/A will be. This will not be anything that affects data transfer, per se. All billion TB of information can be transferred with perfect fidelity; when you open your word document, all the correct words are there. But we don't listen to data files. There has to be analog conversion somewhere. In my living room system, it was always well worth the effort to clean up the power and have well shielded cables. *Do any of the audiophile USB cables actually provide effective power filtering and shielding, such that the headphone amp is cleaner even though connected to the PC? *I don't know. This can be properly done in a living room system. But there are snake-oil produccts there too, of course.


 
   
   
  I am an audiophile with a $7k system. I have only tried one cable that fits that criteria and that's the Revelation Dual Conduit. In my own opinion the cable is anything but snake oil.  If it was I would have immediately returned it. The difference I heard was absolutely positively huge. Like comparing a $300 DAC to a $1500 DAC.
   
  My 2 cents.
   
  But why not just try one for yourself, and just return it if it isn't worth it to you? Not everybody is going to have the same opinion obviously.


----------



## Lorspeaker

Quote: 





robertsong said:


> What??? _Of course_ I did not read the thread. Why would I? LOL
> 
> 
> What could I possibly be misinformed about? I have tried 6 different cables. Some differences were subtle, others were enormous.


 
   
  i am in your camp...the poorer camp.......so which one did u pick finally? 
	

	
	
		
		

		
		
	


	



  sorry didnt see your post just b4....u picked the REV DUAL?


----------



## anetode

Quote: 





robertsong said:


> What??? _Of course_ I did not read the thread. Why would I? LOL
> 
> 
> What could I possibly be misinformed about? I have tried 6 different cables. Some differences were subtle, others were enormous.


 

 You appear to be misinformed about the nature of this thread, the nature of the subforum you're posting in, the psychology of perception, the truth of the value proposition of audiophile cables and the science behind them. That you haven't even considered the possibility of being misinformed about any of these is all the more troubling, if not entirely surprising.


----------



## robertsong

Quote: 





anetode said:


> You appear to be misinformed about the nature of this thread, the nature of the subforum you're posting in, the psychology of perception, the truth of the value proposition of audiophile cables and the science behind them. That you haven't even considered the possibility of being misinformed about any of these is all the more troubling, if not entirely surprising.


 
   
  I will have to ask you once again, how am I misinformed? This argument is not new to me in the least.


----------



## bigshot

I love it when people describe their system in terms of how much money it cost them. That tells us absolutely nothing about the system. You could spend $20,000 and still have crappy sound... or $100,000. Price doesn't matter. How smart you are about choosing your equipment and how you put it all together are the things that make a difference. And spending a lot of money on a USB cable doesn't bode well for that.


----------



## robertsong

Quote: 





lorspeaker said:


> i am in your camp...the poorer camp.......so which one did u pick finally?
> 
> 
> 
> ...


 
   
   
  Yup, $350 from Audiogon. Beat my expectations. It is the "V" cable and I plan to add a PS soon.
   
  What surprised me was how much my sound improved even without the power supply. Could that have something to do with the heavy shielding and noise isolation of the +5V? In my opinion absolutely YES.


----------



## Lorspeaker

some system are so underoptimised, the guy wont hear a diff....
  some system are so optimised, the system cant output anymore diff...
  some guys are tone deaf, no wire will make a diff....
  some guys wont try, so wont hear a diff.


----------



## robertsong

Quote: 





bigshot said:


> You could spend $20,000 and still have crappy sound... or $100,000.


 
   
  Fair enough. I agree with that. But generally the better more revealing components are more expensive. This type of thing can be (and is) proved with double-blind tests.
   
  My point is more revealing systems will reveal greater sound differences in cables (for better or worse) than less revealing systems.
   
  Kinda silly buying a $1000 cable for a $300 DAC right? With a highly revealing DAC such as a M51 or Eximus it's a whole different argument. The differences are often magnified.


----------



## robertsong

Quote: 





lorspeaker said:


> some system are so underoptimised, the guy wont hear a diff....
> some system are so optimised, the system cant output anymore diff...
> some guys are tone deaf, no wire will make a diff....
> some guys wont try, so wont hear a diff.


 
   
   
  I'm not trying to be rude to anybody, and I know all types of people post here. My posts were intended for the original poster and anybody else with similar questions.
   
  And yes Lorspeaker, I have to agree with this.
  To each there own.


----------



## anetode

Quote: 





robertsong said:


> I will have to ask you once again, how am I misinformed? This argument is not new to me in the least.


 
  I'm a little offended that you're not choosing to do your own research on this one, but I have some time to waste.
   
  "the nature of [this] subforum"

 Sound science, the subforum where science and skeptical inquiry are sanctioned by HF. Meaning, if you come out and make an extraordinary claim, you better have some extraordinary evidence to back it up. Your personal anecdotes are rather the opposite of extraordinary.
  "the nature of this thread"

 Part skeptical inquiry/part mockery
  "the psychology of perception"

 If you want to think there's a difference then you will hear a difference (spending exorbitant sums on the promise of a difference compounds this likelihood). If you run a controlled test (DBT) then you will be able to account for your cognitive bias(es).
  "the truth of the value proposition of audiophile [USB] cables"

 From the manufacturer's POV: they're cheap to make, we can sell them for a huge upcharge, and the customer is too damn stupid or self-convinced to know otherwise. Wait, that's not entirely fair, some cable manufacturers are also too stupid or self-convinced to know otherwise.
  "the science behind them"

 Can't summarize briefly, but there are plenty of books out there, simply search for either "digital audio" or "signal transmission" on Amazon. I promise you that no book you'll find will approach the cost of your prized cable.
 Oh, what the hey: the digital signal can be visualized as an eye pattern which is to be deciphered as a series of 1s and 0s. USB as a protocol has several methods to account for timing errors, so does every DAC. As long as a cable meets USB spec it is decipherable by whatever USB equipment.


----------



## jaddie

Quote: 





robertsong said:


> Fair enough. I agree with that. But generally the better more revealing components are more expensive. This type of thing can be (and is) proved with double-blind tests.


 
  Not to pick nits, but care to cite a double-blind that proved this?
   
  oops...just confirming anetode's post...


----------



## jaddie

It's impossible to separate expectation bias from the perception of value when a great deal of money is spent.


----------



## anetode

Quote: 





robertsong said:


> [...] generally the better more revealing components are more expensive. This type of thing can be (and is) proved with double-blind tests.


 
   
  Quote: 





jaddie said:


> Not to pick nits, but care to cite a double-blind that proved this?


 
   
  I think he might have been talking about components excluding USB cables, unless those are proper components in their own right in that reference.
   
  Also, I forgot to add that in fairness, the assertion that people who hear differences in expensive USB cables are "self-convinced" can be countered by saying that people who can't hear a difference are self-convinced or simply haven't had a chance to hear better. The explanation for the former also sheds light on the latter.
   
  Yes, cognitive biases works both ways, so if someone is _expecting_ that there is no difference, they might not notice one. This, again, is where the collection of evidence combines with its purpose: confirming or proving wrong hypotheses, theories, of technical knowledge in general. A single DBT test is nothing if it is not repeatable, whether by improper methodology or statistical improbability. It is also not very much if we can't then measure why there's no audible difference and then explain that measurement with congruent results achieved at by mathematical modeling. To a naive cable advocate (naive in the plain, non-derogatory sense) one technical explanation for a cable's superior performance is comparable to a technical explanation to why it is nothing more then snake oil. Indeed the technical claim of superiority is naturally desirable, but it is so for a host of psychological reasons rather than technical understanding.
   
  Once the cable advocate has affirmed their conviction in their purchase they may be tempted to maintain it as a status symbol. That's where you get the passive-aggressive "well, to each his own (I hope some day you get to hear just how good this sounds)" argument. It's more comforting to think that someone is jealous than to consider that they're simply not interested in what you hold dear. It's also easier to consider someone ignorant than to think that you're the one who is misinformed and wrong. I've fallen in the latter trap before enough times to keep an open mind, but the journey has also raised my standards of evidence and logic. Sad to say that I've never run across a cable advocate argument which has satisfied those standards.


----------



## jaddie

Quote: 





anetode said:


> I think he might have been talking about components excluding USB cables, unless those are proper components in their own right in that reference.


 
   No doubt.  Still, it's always good to support a statement like that one, as if true, would be very significant and initiate a whole lot of research.
  Quote:


anetode said:


> Also, I forgot to add that in fairness, the assertion that people who hear differences in expensive USB cables are "self-convinced" can be countered by saying that people who can't hear a difference are self-convinced or simply haven't had a chance to hear better. The explanation for the former also sheds light on the latter.
> 
> Yes, cognitive biases works both ways, so if someone is _expecting_ that there is no difference, they might not notice one. This, again, is where the collection of evidence combines with its purpose: confirming or proving wrong hypotheses, theories, of technical knowledge in general. A single DBT test is nothing if it is not repeatable, whether by improper methodology or statistical improbability. It is also not very much if we can't then measure why there's no audible difference and then explain that measurement with congruent results achieved at by mathematical modeling. To a naive cable advocate (naive in the plain, non-derogatory sense) one technical explanation for a cable's superior performance is comparable to a technical explanation to why it is nothing more then snake oil. Indeed the technical claim of superiority is naturally desirable, but it is so for a host of psychological reasons rather than technical understanding.
> 
> Once the cable advocate has affirmed their conviction in their purchase they may be tempted to maintain it as a status symbol. That's where you get the passive-aggressive "well, to each his own (I hope some day you get to hear just how good this sounds)" argument. It's more comforting to think that someone is jealous than to consider that they're simply not interested in what you hold dear. It's also easier to consider someone ignorant than to think that you're the one who is misinformed and wrong. I've fallen in the latter trap before enough times to keep an open mind, but the journey has also raised my standards of evidence and logic. Sad to say that I've never run across a cable advocate argument which has satisfied those standards.


 
  Just wanted to say "Thank You" for such a thoughtful and insightful post.  Well said.  
   
  Many decades ago I was perplexed by the introduction of Monster Cable speaker wire, and sort of dove in a bit on the assumption that there certainly must be a reason for the claims of better sound.  What I ran into along the way was a lot of claims without substantiation, which also was a bother because they were clustered about each other so tightly that one would think there was something real going on.  My own testing was limited, but uncovered nothing other than cable size and length being a factor equally applicable to any product.  Then I read Richard Greiner's 1980 AES paper, "Loudspeaker-Amplifier Interfacing" and just stopped working on it, he answered the question.  Greiner followed up with another AES paper and the Audio magazine article in the early 1990s. Then the 1991 paper, "Effects of Cable, Loudspeaker, and Amplifier Interactions" by Fred Davis put some examples into practical light, and did present some conditions under which speaker cable could have an audible effects.  Useful information, but doesn't point to exotics as the only solution either.  But it does show that cable interactions may be audible, which when present then reinforces the expectation bias based on price, visual, anecdote, etc., and you can see why the entire argument perpetuates for the next 20+ years.  There is fact down in there, it can be real, and science has shown conditional cable effects, but it's critical to understand the conditions, and the simple ways to avoid them.  
   
  No idea what we'll find if tests of similar quality were done with USB cables and devices.  My suspicion is that similar results may be found, specific conditions under which a cable has an impact.  The key again, what are those conditions, and how to avoid them.  For USB cables, the conditions will include the devices on each end, and how they actually handle the data passed between them, so we won't be just testing cables, but specific devices and their sensitivity to cable properties.  
   
  Fffew.  Another research paper.  C'mon, grad students, lets get going!


----------



## ultrabike

Quote: 





robertsong said:


> What??? _Of course_ I did not read the thread. Why would I? LOL
> 
> 
> *What could I possibly be misinformed about?* I have tried 6 different cables. Some differences were subtle, others were enormous.


 
   
  Could you provide information regarding how and why these 6 different cables perform so enormously different?
   
  Quote: 





robertsong said:


> Yup, $350 from Audiogon. Beat my expectations. It is the "V" cable and I plan to add a PS soon.
> 
> What surprised me was how much my sound improved even without the power supply. *Could that have something to do with the heavy shielding and noise isolation of the +5V? In my opinion absolutely YES*.


 
   
  Interesting. How do heavy shielding and cable isolation prevent power supply noise from coupling to the signal, when the power supply noise couples to the signal before it even arrives to the wire connectors?


----------



## bigshot

Quote: 





robertsong said:


> Fair enough. I agree with that. But generally the better more revealing components are more expensive.


 
   
  Above midrange equipment, I haven't found any correlation between cost and sound quality. Build quality? Yes, but not sound quality. Some of the most expensive equipment is deliberately colored, and some midrange equipment measures stone flat and clean. Generally people who attack the problem of getting good sound by just going out and buying expensive equipment do that because they don't know any other way to solve it.


----------



## robertsong

Quote: 





ultrabike said:


> Could you provide information regarding how and why these 6 different cables perform so enormously different?


 
   
  I would imagine that would have to with the different manufactures use different constructions and materials. As far as my testing I have used nothing but my own ears. What a novel concept!
   
  To me you are looking at it completely backwards. What good would a fancy designed cable be if it did not sound subjectively better than Lacie Flat of Belkin Gold? That to me would be an enormous waste of money.
   
   
  Quote: 





> Interesting. How do heavy shielding and cable isolation prevent power supply noise from coupling to the signal, when the power supply noise couples to the signal before it even arrives to the wire connectors?


 
   
   
  Why is this question directed at me? You will get a much more detailed and accurate explanation from the engineer himself. But better yet, why not demo a high end cable and use your own ears to determine if it's worth the money? If not, return it. How hard is that?


----------



## bigshot

robertsong said:


> What good would a fancy designed cable be if it did not sound subjectively better than Lacie Flat of Belkin Gold?




That is an excellent question!


----------



## ultrabike

Quote: 





robertsong said:


> I would imagine that would have to with the different manufactures use different constructions and materials. As far as my testing I have used nothing but my own ears. What a novel concept!
> 
> To me you are looking at it completely backwards. What good would a fancy designed cable be if it did not sound subjectively better than Lacie Flat of Belkin Gold? That to me would be an enormous waste of money.


 
   
  "Using my own ears" is not a novel concept. We all do. Now other than your own ears, do you have any explanation(s) to backup "superior" performance claims of certain cables?
   
  If someone designed whatever cable product and knew what he/she was doing, he/she probably had a BOTH a subjective goal in mind and a means to quantify this goal... Could you site an example?
   
  Quote: 





robertsong said:


> Why is this question directed at me? You will get a much more detailed and accurate explanation from the engineer himself. But better yet, why not demo a high end cable and use your own ears to determine if it's worth the money? If not, return it. How hard is that?


 
   
  This question is directed at you because you are referring to others as misinformed and yourself as not misinformed. To me that means you are well informed about the performance of certain cables and cables in general, including their objective performance and technical specs... is that not so?


----------



## robertsong

Quote: 





anetode said:


> Sad to say that I've never run across a cable advocate argument which has satisfied those standards.


 
   
  But who really cares about these audiophile cable arguments? There is no point in being a total weenie and try to rational everything when you can simply use your own ears and draw your own conclusions? How can you argue against a "high end" $500+ cable if you have never heard one???  I have heard cables from several price levels and that is what I based my conclusion on.
   
   
  My advice is try different cables and decide for yourself what sounds best. There is no need to make this any more complicated that it is. Sheesh.


----------



## robertsong

Quote: 





ultrabike said:


> "Using my own ears" is not a novel concept. We all do. Now other than your own ears, do you have any explanation(s) to backup "superior" performance claims of certain cables?
> 
> If someone designed whatever cable product and knew what he/she was doing, he/she probably had a BOTH a subjective goal in mind and a means to quantify this goal... Could you site an example?
> 
> ...


 

 No, no, no. I am informed b/c I have took the time to compare several different levels of cables and I have drawn my own conclusion from that.. and solely that. Others including yourself clearly have not there is no point in arguing with you if you won't try it for yourself. When I hear a general smack you in face difference I call it "objective" b/c the sound _difference_ can not be denied. Notice I have said "difference" not "better" or "worse". Only you can decide that.
   
  So why not try it for yourself? Otherwise your counter-argument will not prove anything.


----------



## ultrabike

Quote: 





robertsong said:


> But who really cares about these audiophile cable arguments? There is no point in being a total weenie and try to rational everything when you can simply use your own ears and draw your own conclusions? How can you argue against a "high end" $500+ cable if you have never heard one???  I have heard cables from several price levels and that is what I based my conclusion on.
> 
> 
> My advice is try different cables and decide for yourself what sounds best. There is no need to make this any more complicated that it is. Sheesh.


 
   
  Is there any particular high-end high-performance cable you vouch for that is readily available for trial?


----------



## ultrabike

Quote: 





robertsong said:


> No, no, no. I am informed b/c I have took the time to compare several different levels of cables and I have drawn my own conclusion from that.. and solely that. Others including yourself clearly have not there is no point in arguing with you if you won't try it for yourself. When I hear a general smack you in face difference I call it "objective" b/c the sound _difference_ can not be denied. Notice I have said "difference" not "better" or "worse". Only you can decide that.
> 
> So why not try it for yourself? Otherwise your counter-argument will not prove anything.


 
   
  You are being very vague here. What cables did you found to be very different in a positive way with what equipment?
   
  And why are you posting all of this in the Sound Science forum if you don't have any scientific evidence to support your stance? I'm not denying your hearing of differences with different cables... but there is a forum for that... AFAIK this is not it.


----------



## radiofrog

Quote: 





ultrabike said:


> ... but there is a forum for that... AFAIK this is not it.


 
   
  This may not be the forum for it, but I'm finding this entertaining.


----------



## anetode

Quote: 





robertsong said:


> But who really cares about these audiophile cable arguments? There is no point in being a total weenie and try to rational everything when you can simply use your own ears and draw your own conclusions? How can you argue against a "high end" $500+ cable if you have never heard one???  I have heard cables from several price levels and that is what I based my conclusion on.
> 
> 
> My advice is try different cables and decide for yourself what sounds best. There is no need to make this any more complicated that it is. Sheesh.


 
  There's no point to shutting down your mind and opening your wallet either. Though I like your total weenie argument, it reminds me of kids daring each other to eat dirt.
   
  Wouldn't you know it, I have heard audiophile USB cables, much to my chagrin, at hifi shows and hifi retailers. They didn't make a difference with expensive DACs and they didn't make a difference with the SanDisk Clip I brought along. I've also had my hearing checked, turns out that it works quite well. So where's the difference? Could it be in your mind?


----------



## jaddie

Quote: 





robertsong said:


> But who really cares about these audiophile cable arguments? There is no point in being a total weenie and try to rational everything when you can simply use your own ears and draw your own conclusions? How can you argue against a "high end" $500+ cable if you have never heard one???  I have heard cables from several price levels and that is what I based my conclusion on.
> 
> 
> My advice is try different cables and decide for yourself what sounds best. There is no need to make this any more complicated that it is. Sheesh.


 
   
  Well, as said in this thread, using just using your ears doesn't get around flaws in judgement caused by expectation bias. It's not that easy to audition USB cables.  
   
  Assuming your'e working with a PC and a DAC, usb connected.  Here's what you need to test and use _*only*_ your ears:
   
  A computer with multi-track audio software (Audition, Audacity, similar) with two USB connections
  Several audio test selections.
  A way to test both DACS for level match
  A way of switching your headphones (or audio system) between the DACs, Choice A and Choice B
  A way to switch to a third choice (C) equal to DAC1 or DAC2, but not known to the tester which it is
  A way to scramble which DAC is on Choice 3 for at lest 20 tests
  A way to recover a "truth table" that lists what Choice 3 was after the tests are completed
  Two USB cables to test
   
  Prep:
  Two copies of test audio file is placed into the software so they appears in two stereo sets of tracks, positioned to play in perfect sync.  On stereo set is routed to DAC 1, the other to DAC 2.
   
  Then...
  The tester listens to both choice Choice A and Choice B, switching between them at will.
  The tester then listens to Choice C, and attempts to match it to Choice A or B, and records his decision.
   
  After collecting data for about 20 test cycles, swap the DACs USB connections and do it again.  This is necessary to eliminate differences in the two USB connections at the computer.
   
  Tally it all up, see if the results show that DACS can be matched reliably to an unknown choice to , say, 60% or better accuracy.  
   
  What you'd have then is good data, using just your ears, that would show a different cables present an audible difference with equipment in your test setup.  It would not prove the same cables would be different in a different setup, with different DACs, USB connections, etc.  
   
  Ok.......GO!


----------



## bigshot

Listening tests can be very useful as long as you deal with the issues of expectation bias, auditory memory and volume matching. How did you deal with those issues when you did a comparison of high end USB cables?


----------



## ab initio

Quote: 





robertsong said:


> How can you argue against a "high end" $500+ cable if you have never heard one???


 
   
  Here is how I propose arguing against $500 cables if you haven't heard them:
  USB has a set of specifications [http://www.usb.org/developers/docs/] such that a system whose components are all operating within specification will behave in a deterministic fashion. If you have a USB cable which meets the electrical specifications of the USB standard, and this cable connects two devices who also operate within the USB specifications, then the result of swapping the USB cable with another USB cable which also meets the USB specifications will be identical behavior. Any deviation in behavior is the result of _one of the components_ not meeting the USB standard. Therefore, if you replace a $500 cable (that meets or exceeds USB specification) with another cable that also meets the USB specification (regardless of price) and you get a different result, then you can conclude that _one of the components is faulty_ (in the sense that it doesn't meet the USB specification). It's not the cable.
   
  If the only USB cables that meet the proper specification cost $500+, then I completely agree with you that the $500+ cables can't be argued against.
   
  Cheers
   
  [edit] to fix link and grammar


----------



## robertsong

Quote: 





anetode said:


> There's no point to shutting down your mind and opening your wallet either. Though I like your total weenie argument, it reminds me of kids daring each other to eat dirt.
> 
> Wouldn't you know it, I have heard audiophile USB cables, much to my chagrin, at hifi shows and hifi retailers. They didn't make a difference with expensive DACs and they didn't make a difference with the SanDisk Clip I brought along. I've also had my hearing checked, turns out that it works quite well. So where's the difference? Could it be in your mind?


 
   
  I have treated my cable connectors with Deoxit Gold, and I have added Isopod feet under my DAC. I believe both of those made some sound improvement, but I cannot be certain it wasn't "just in my mind".
   
  With the Dual-Conduit it was not one of these cases. The improvement was not subtle in the least. It was a genuine smack me in the face difference from the Lacie Flat cable which I was using for six months. I did not "A/B" them, and if I actually felt a need to do that I would have returned the cable immediately. Why dish out $350 for a subtle improvement? I could just use that cash towards a better DAC, right?
   
  I would have never even bothered to mentioned the dual-conduit here if I did not feel so strongly about the improvement. As I said before, it beat my expectations. I look for even further improvement when I add-on a dedicated +5V power supply ( many on HF praise this method).
   
  I'm sorry to hear your experience with audiophile USB cables was completely unlike mine. I find this interesting. Can I ask which cables and DACs you heard that let you to your conclusion?
   
  The other cables that seem to get alot of praise in magazines and internet are the WW Platinum Starlight, Acoustic Revive, King Rex Y cable, and the Locus Design Polestar, FWIW.


----------



## anetode

Quote: 





robertsong said:


> I'm sorry to hear your experience with audiophile USB cables was completely unlike mine. I find this interesting. Can I ask which cables and DACs you heard that let you to your conclusion?


 
  I do too and I will answer your question after you answer mine: could this difference that you hear be all in your mind (e.g. a result of expectation bias)? If not, how do you know?


----------



## robertsong

Quote: 





ab initio said:


> If the only USB cables that meet the proper specification cost $500+, then I completely agree with you that the $500+ cables can't be argued against.
> 
> Cheers
> 
> [edit] to fix link and grammar


 
   
   
  Proper specification? Any POS USB cable can have the proper computer specs.  What were talking about here with audiophile cables is minimizing jitter that is introduced within the cable, and minimizing extraneous noise as well as the noise from it's own +5v line. That is what accounts for sound differences. I know that is not what you want to believe, and you most likely won't research much into the subject, but if you wanted to you could certainly find the right answers to satisfy you.


----------



## robertsong

Quote: 





anetode said:


> I do too and I will answer your question after you answer mine: could this difference that you hear be all in your mind (e.g. a result of expectation bias)? If not, how do you know?


 
  Read more carefully. I thought I tackled that thoroughly.
   
  Which cables? Huh?


----------



## bigshot

You didn't take the trouble to find out if there really was a difference. Auditory memory is measured in seconds. If you didn't do a direct A/B, you can't know if there was a difference or not. You couldn't have accurately level matched either, although I don't think that's the problem here. You also didn't do a blind test, so you're subject to expectation bias.

None of this is meant as a criticism of you. But there shouldn't be a difference between functioning USB cables. If there is, either one of them is defective and should be replaced, or your comparison isn't controlled enough.

I get USB cables from Monoprice that work as good as any other USB cable out there at any price. You might try them next time and save yourself a lot of money. Doing carefully controlled comparison tests will help a lot with that too.


----------



## robertsong

Oh this is interesting...
   
   
  I see you have both the HD650 and HD800 in your headphone inventory. Great headphones! Can I assume you hear very little difference between these? Quite a big price difference there between those two.


----------



## bigshot

robertsong said:


> Proper specification? Any POS USB cable can have the proper computer specs.  What were talking about here with audiophile cables is minimizing jitter that is introduced within the cable, and minimizing extraneous noise as well as the noise from it's own +5v line. That is what accounts for sound differences. I know that is not what you want to believe, and you most likely won't research much into the subject, but if you wanted to you could certainly find the right answers to satisfy you.




I've done the research into the subject. I'm afraid you're wrong. Even the cheapest USB cable doesn't cause jitter or line noise at audible levels.


----------



## bigshot

robertsong said:


> I see you have both the HD650 and HD800 in your headphone inventory. Great headphones! Can I assume you hear very little difference between these? Quite a big price difference there between those two.




The difference between transducers... even different samples of the same model are MUCH more audible than the difference between modern digital hifi components and cables.

If you're interested, you should read a few of the threads in the Sound Science forum. There are some very knowledgeable people in this forum. Lots to learn.


----------



## ultrabike

Quote: 





robertsong said:


> Proper specification? Any POS USB cable can have the proper computer specs.  What were talking about here with audiophile *cables is minimizing jitter that is introduced within the cable*, and *minimizing extraneous noise* as well as the *noise from it's own +5v line*. That is what accounts for sound differences. I know that is not what you want to believe, and you most likely won't research much into the subject, but if you wanted to you could certainly find the right answers to satisfy you.


 
   
  Jitter: Jitter is best removed with a jitter attenuator at the receiving end, and maybe some sort of pre-emphasis at the transmitting end. Cable is limited in what it can do about jitter, specially the one introduced prior to the connector.
   
  Extraneous noise: Shielding can help on *long runs*. On short runs you might need to worry about the connector as well, which might require shielding. Connectors need to be standard compliant to couple mechanically, and so there is so much you can do as far as that...
   
  Noise from the +5v line: That noise couples before the signal even hits the connector AFAIK. Cable cannot remove this noise without mangling the signal itself. A jitter attenuator with some re-clocking scheme or such at the receiving end might help though.
   
  ... Furthermore, are you referring to these purple $550 thingies?:
   
http://revelationaudiolabs.com/cables-digital/#USB


----------



## jaddie

Quote: 





robertsong said:


> Oh this is interesting...
> 
> 
> I see you have both the HD650 and HD800 in your headphone inventory. Great headphones! Can I assume you hear very little difference between these? Quite a big price difference there between those two.


 
  Woa, slow down. You wouldn't be suggesting the differences between headphones (easily measured, by the way) and USB cables are similar, are you?


----------



## robertsong

Quote: 





bigshot said:


> You didn't take the trouble to find out if there really was a difference. Auditory memory is measured in seconds. If you didn't do a direct A/B, you can't know if there was a difference or not. You couldn't have accurately level matched either, although I don't think that's the problem here. You also didn't do a blind test, so you're subject to expectation bias.
> 
> None of this is meant as a criticism of you. But there shouldn't be a difference between functioning USB cables. If there is, either one of them is defective and should be replaced, or your comparison isn't controlled enough.
> 
> I get USB cables from Monoprice that work as good as any other USB cable out there at any price. You might try them next time and save yourself a lot of money. Doing carefully controlled comparison tests will help a lot with that too.


 
   
   
  This is mind-boggling erroneous and I can't even fathom arguing with you. I encourage you to talk a legitimate audio engineer. He/she will gun you down on every point. I have seen it many times before. Not likely to happen on Head-Fi, though.
   
  Oh well, believe whatever you want to believe.


----------



## ultrabike

Quote: 





robertsong said:


> Oh this is interesting...
> 
> 
> I see you have both the HD650 and HD800 in your headphone inventory. Great headphones! Can I assume you hear very little difference between these? Quite a big price difference there between those two.


 
   
  The differences between an HD650 and an HD800 are fairly well documented (objective and subjective.) I've have heard both, and they do sound different. So far all you have provided regarding your cable thingies is "I hear a difference" ... "try it!"


----------



## robertsong

Quote: 





jaddie said:


> Woa, slow down. You wouldn't be suggesting the differences between headphones (easily measured, by the way) and USB cables are similar, are you?


 
   
   
   With the dual-conduit, and only the dual-conduit, I say yes. I don't know how many times I have to repeat it... the difference smacked me right across the face.


----------



## anetode

Quote: 





robertsong said:


> Read more carefully. I thought I tackled that thooughly.
> 
> Which cables? Huh?


 

 No, you've only been dancing around it. It hasn't been so much a tackle as a light breeze, as if someone standing next to you in an elevator is expelling digestive gases while smiling and telling you it smells like lilacs. Simply respond: "yes it might be all in my mind" or "no, and here's why I think so".
   
  Since you've brought up jitter and noise rejection, you should also be aware that the people who came up with the USB spec are indeed engineers who have studied these topics from the introductory courses all the way to the latest research. This is not to say that you should accept their authority, but you should be well aware of the fact that in this field they are the authority. Besides which all of your arguments are based on what you have heard in an uncontrolled test and the purported authority and technical merits of arguments from cable manufacturers. It would help if you explain how/why the purported benefits in noise and jitter suppression allow fancy cables to outperform a regular in-spec USB cable attached to a regular DAC with standard jitter rejection measures in place.


----------



## bigshot

robertsong said:


> This is mind-boggling erroneous and I can't even fathom arguing with you. I encourage you to talk a legitimate audio engineer. He/she will gun you down on every point. I have seen it many times before. Not likely to happen on Head-Fi, though.




I'm not arguing at all. I'm simply answering your questions. I've worked in the entertainment business for almost thirty years now, serving in the capacity of recording supervisor and post production supervisor. I've worked with many, many sound engineers and I've done a fair bit of it myself.

It turns out that you're speaking to a sound guy on Head-Fi. There are already a few of us right here in this thread speaking to you in fact. Would you like to hear what we have to say? It seems that you have been getting your info from high end audio sales literature rather than sound engineers. It might be interesting for you to hear what a sound engineer REALLY has to say.


----------



## robertsong

Quote: 





ultrabike said:


> The differences between an HD650 and an HD800 are fairly well documented (objective and subjective.) I've have heard both, and they do sound different. So far all you have provided regarding your cable thingies is "I hear a difference" ... "try it!"


 
   
   
  Hi, try the Audiogon  and Audio Circles forums. I believe you will find what you are looking for. If not, and you are still legitamately interested I can give you some engineering contacts. But why not start with the company itself? Why not hear what they have to say? Tell him your skeptical and want to know what specifically accounts for the better sound. If your polite, maybe he'll mail you a demo.


----------



## bigshot

Would you please provide us with your engineering contacts regarding audible differences between USB cables relating to line noise and jitter?


----------



## robertsong

Quote: 





bigshot said:


> I'm not arguing at all. I'm simply answering your questions. I've worked in the entertainment business for almost thirty years now, serving in the capacity of recording supervisor and post production supervisor. I've worked with many, many sound engineers and I've done a fair bit of it myself.
> 
> It turns out that you're speaking to a sound guy on Head-Fi. There are already a few of us right here in this thread speaking to you in fact. Would you like to hear what we have to say? It seems that you have been getting your info from high end audio sales literature rather than sound engineers. It might be interesting for you to hear what a sound engineer REALLY has to say.


 
   
   
  Engineers as in people who actually design audio equipment. Not sound engineers. Go ahead and email some of the higher end DAC companies and tell them you can't believe that a USB can sound different. Report back what they tell you.


----------



## ultrabike

Quote: 





robertsong said:


> Hi, try the Audiogon  and Audio Circles forums. I believe you will find what you are looking for. If not, and you are still legitamately interested I can give you some engineering contacts. But why not start with the company itself? Why not hear what they have to say? Tell him your skeptical and want to know what specifically accounts for the better sound. If your polite, maybe he'll mail you a demo.


 
   
  Welp.... Looks like I'll be on my way to T.H.E Show @ Newport tomorrow and will give them cables a shot... Not sure if the ones you particularly mention will be there, but I'm sure I'll hit a few others...
   
  Be aware that folks here (myself included) would like more than just "I hear the difference." And that some folks here have gone through several uber cables already, and came out unimpressed...


----------



## bigshot

I've read published specs for high end DACs and compared them to the published specs of typical DACs in iPods and midrange CD players. Although there are differences, all of the differences are far beyond the range of human perception. The levels of jitter in the most humble CD player is an order of magnitude lower than any human can hear. Jitter, as it occurs in modern digital audio is just not a problem in playback of music in the home.

I've done this research. Would you like to hear the facts instead of just the sales pitch you've been given so far?


----------



## robertsong

Quote: 





bigshot said:


> Would you please provide us with your engineering contacts regarding audible differences between USB cables relating to line noise and jitter?


 
  PLEASE.. PLEASE.. PLEASE..
   
  post what you posted to me in these forums
   
  http://forum.audiogon.com/cgi-bin/fr.pl
  http://www.audiocircle.com
   
  You will undoubtably get your full technical explanations there.


----------



## ultrabike

Quote: 





robertsong said:


> Engineers as in people who actually design audio equipment. Not sound engineers. Go ahead and email some of the higher end DAC companies and tell them you can't believe that a USB can sound different. Report back what they tell you.


 
   
  I know of at least one company that designs $700 to $800 DACs and Amps than doesn't necessarily think highly of uber expensive cables... I believe some high end headphone amplifier designers (north of $6k) don't think too highly of them either... Maybe I'll ask them tomorrow...
   
  I also know of a few sound engineers that don't find uber USB cables a hot item at all...


----------



## robertsong

Quote: 





ultrabike said:


> Welp.... Looks like I'll be on my way to T.H.E Show @ Newport tomorrow and will give them cables a shot... Not sure if the ones you particularly mention will be there, but I'm sure I'll hit a few others...
> 
> Be aware that folks here (myself included) would like more than just "I hear the difference." And that some folks here have gone through several uber cables already, and came out unimpressed...


 
   
   
  If you are telling me the truth, please seek out Steve from Empirical Audio while you are there. He will be able to tackle anything you throw at him. Then again, I would guess any high-end digital guru could do that.


----------



## ultrabike

Quote: 





robertsong said:


> If you are telling me the truth, please seek out Steve from Empirical Audio while you are there. He will be able to tackle anything you throw at him. Then again, I would guess any high-end digital guru could do that.


 

 I've heard some of Steve's products and they did seem to work. He doesn't sell "uber" cables though. I liked his Off-Ramp USB Converter. But I hated it's mundane presentation and it's price.
   
  I can also tell you that the USB converter will not turn an HD202 into an SR-009...


----------



## ab initio

Quote: 





robertsong said:


> Proper specification? Any POS USB cable can have the proper computer specs.  What were talking about here with audiophile cables is minimizing jitter that is introduced within the cable, and minimizing extraneous noise as well as the noise from it's own +5v line. That is what accounts for sound differences. I know that is not what you want to believe, and you most likely won't research much into the subject, but if you wanted to you could certainly find the right answers to satisfy you.


 

 I've been doing some personal research into jitter for the past 5 months to try and parse out fact from fiction. I do not deny the existence of jitter, nor the fact that it may have an audible impact in some cases. However, you can't say "Jitter, QED" to argue that you need $500+ USB cables. Jitter needs to be addressed in the DAC design to account for the tolerances in the transport specifications. If the DAC is designed correctly, it buffers enough data to absorb the jitter occurs within the USB specification, and the resulting bit stream that is being converted by the D to A will be clocked with a low-jitter onboard clock that is _independent _of the USB clock. As long as your USB components are within spec, the analog output is not affected by USB timing problems, let alone the timing variation introduced by regular cables.
   
  The problem with USB and jitter is that USB transfer is clocked by a jittery computer clock. Only a low quality DAC would depend on a USB clock for the D to A timing. If this is the case, I'd be interested in any sources that can clarify the amount of jitter introduced only by the cable, and how it looks in relationship to the jitter of the CPU clock.
   
  I'm very happy to be corrected if you can point me to the correct information.
   
  Cheers


----------



## bigshot

You suggested to me that my experience in sound recording and post production was irrelevant, and you refer me to an internet forum and a company that sells high end computer cables. I'll offer you a bit of useful advice...

The people who know about a subject and are willing to honestly share their knowledge with you are the ones who use the technology on a daily basis. A salesman is going to just tell you what he thinks will get you to buy the product. That's his job. You would do a lot better to be a little skeptiical of what you are being told by sales reps. Fact check what they're telling you with people who work with the technology professionally, and organizations like AES (Audio Engineering Society) that operates controlled scientific tests to verify claims and identify the thresholds of perception.

You are posting in the sound science forum. This is the forum where it is all right to ask for controlled tests to verify anecdotal listening claims. We're not arguing with you. We're the ones that are trying to help you get the truth.


----------



## anetode

Quote: 





robertsong said:


> If you are telling me the truth, please seek out Steve from Empirical Audio while you are there. He will be able to tackle anything you throw at him. Then again, I would guess any high-end digital guru could do that.


 
  No, most engineers would disagree with your assertions. There's a way to test this too, ask a random sampling of electrical engineers with audio backgrounds who are not trying to sell you exorbitantly priced audio wares. Steve, as a digital guru, might agree - but then your phrasing has already turned him into an exalted authority and you're not even doing us the courtesy of properly reciting his dogma. You appear to be waving away any attempt at substantive discussion by pointing either to your own ears or other forums or to what amounts to little more than advertising literature.


----------



## ab initio

Quote: 





ultrabike said:


> I can also tell you that the USB converter will not turn an HD202 into an SR-009...


 
  You mean there's no hope for my HD202's?


----------



## ultrabike

Quote: 





anetode said:


> No, most engineers would disagree with your assertions. There's a way to test this too, ask a random sampling of electrical engineers with audio backgrounds who are not trying to sell you exorbitantly priced audio wares. Steve, as a digital guru, might agree - but then your phrasing has already turned him into an exalted authority and you're not even doing us the courtesy of properly reciting his dogma. You appear to be waving away any attempt at substantive discussion by pointing either to your own ears or other forums or to what amounts to little more than advertising literature.


 
   
  LOL! The only thing approaching an "audiophile grade" USB cable from Steve seems to be his Short Block USB Filter... Which cannot be used with devices depending on USB for power since it severs the 5V supply. In other words, it does not "clean" the power source... I just don't see how a mere cable can do that with out damaging signal integrity.
   
  I also don't like Steve prices...


----------



## anetode

Quote: 





ab initio said:


> The problem with USB and jitter is that USB transfer is clocked by a jittery computer clock. Only a low quality DAC would depend on a USB clock for the D to A timing. If this is the case, I'd be interested in any sources that can clarify the amount of jitter introduced only by the cable, and how it looks in relationship to the jitter of the CPU clock.


 
   
  According to USB 2.0 spec cable delay may be no more than 5.2ns/m (.64c). Worst case scenario, at the 5m max length, is then 26ns, which is near the tested audibility threshold. Of course this is prior to being processed by a PLL or ASRC. Maximum round-trip is 1.5 μs before the host considers it lost.


----------



## ultrabike

Quote: 





ab initio said:


> You mean there's no hope for my HD202's?


 
   
  There is. You can tune it's frequency response by playing with the miniature bass port inside the enclosure. It helps with the bass and the lower mids. Something else needs to be done to fix the tremble though. It's not a bad headphone for the price IMHO.


----------



## esldude

Quote: 





anetode said:


> No, most engineers would disagree with your assertions. There's a way to test this too, ask a random sampling of electrical engineers with audio backgrounds who are not trying to sell you exorbitantly priced audio wares. Steve, as a digital guru, might agree - but then your phrasing has already turned him into an exalted authority and you're not even doing us the courtesy of properly reciting his dogma. You appear to be waving away any attempt at substantive discussion by pointing either to your own ears or other forums or to what amounts to little more than advertising literature.


 
   
   
  So are you saying don't ask any smart engineers?


----------



## liamstrain

> Originally Posted by *robertsong*
> 
> There is no point in being a total weenie and try to rational everything when you can simply use your own ears and draw your own conclusions?
> 
> ...


 
   
   
1. Because our ears and brains lie to us (all the time). You must deal with various biases - DBT's and null tests will help inform your listening tests. If you think you hear a difference, but the measurements consistently do not show them, you need to re-evaluate what you think you heard. 
   
  2. I have heard many of them. And I have done some objective testing (null tests). I did not hear or see differences in any properly functioning cable built to USB 2.0 spec. The $8 cable performed just as well as the $500 ones Wireworld Platinum, Audioquest Diamond, among them. This, both on my personal equipment, and with the big professional gear at the studio - lest you think my kit isn't resolving enough. 
   
  But as for how to argue against them if you haven't heard one - again, objective tests. Also a solid knowledge of the way digital audio works. I don't need to drive a car that claims to get 500 miles to the gallon using the same spec as one that gets 25 to evaluate that claim. Even without a direct experience, I can evaluate the engineering and theory to see if it even CAN achieve the claim, never mind does. 
   
  3. Good for you. Biased listening experiences are not considered evidence in this forum - nor would they be by many of your audio engineering buddies.


----------



## White Lotus

Quote: 





robertsong said:


> I encourage you to talk a legitimate audio engineer. He/she will gun you down on every point.


 

 Fully qualified, full time audio engineer here.

 Fun fact: If you are linking two digital systems, all you need is a cable that will:
  

 Run at the required bandwidth 
 Be compliant with the required spec (In this case, USB 2.0)
 Not be broken (Each digital standard has a maximum loss rate, before it drops out completely)
   
  I really hate to be so blunt, but hey - this is sound science.


----------



## Greenleaf7

robertsong said:


> I have treated my cable connectors with Deoxit Gold, and I have added Isopod feet under my DAC. I believe both of those made some sound improvement, but I cannot be certain it wasn't "just in my mind".
> 
> With the Dual-Conduit it was not one of these cases. The improvement was not subtle in the least. It was a genuine smack me in the face difference from the Lacie Flat cable which I was using for six months. I did not "A/B" them, and if I actually felt a need to do that I would have returned the cable immediately. Why dish out $350 for a subtle improvement? I could just use that cash towards a better DAC, right?
> 
> ...




I had my $10 USB cable blessed by the pope. Now it sounds even better then my $500 one.


----------



## jaddie

Quote: 





robertsong said:


> This is mind-boggling erroneous and I can't even fathom arguing with you. I encourage you to talk a legitimate audio engineer. He/she will gun you down on every point. I have seen it many times before. Not likely to happen on Head-Fi, though.
> 
> Oh well, believe whatever you want to believe.


 
  ...um....some of us here are legitimate audio engineers here.  Not sure you really want to go down that road.  Though, it's odd.  You make claims about USB cables affecting sound without any engineering-syle proof, then direct those that disagree to talk to engineers.  
   
  Why not save us all a lot of time and typing an just post your engineering data from your legitimate engineers? Or reference a paper, book, or article? That's one sure way to shut the rest of us engineers up for a while.


----------



## uchihaitachi

Quote: 





robertsong said:


> Engineers as in people who actually design audio equipment. Not sound engineers. Go ahead and email some of the higher end DAC companies and tell them you can't believe that a USB can sound different. Report back what they tell you.


 
  He must be a troll?


----------



## jaddie

Quote: 





uchihaitachi said:


> He must be a troll?


 
   
  Possibly, but I hate to label. I don't think I'm being presumptuous in stating that several of us here still qualify.


----------



## uchihaitachi

Quote: 





jaddie said:


> Possibly, but I hate to label. I don't think I'm being presumptuous in stating that several of us here still qualify.


 
  I must say having read what he wrote again, it's far too detailed and in depth to be merely a farce...


----------



## leogodoy

robertsong said:


> Why dish out $350 for a subtle improvement?




I have a hunch...

No, really, the point is, when you accused us of "Looking at it completely backwards" you got really close to the answer. check it out:

"What good would a fancy designed cable be if it did not sound subjectively better than Lacie Flat of Belkin Gold? That to me would be an enormous waste of money."

That sentence alone explains everything. People see $$$$ and almost instantly think, nay, they KNOW it relates to quality. This makes the life of companies easier: put a more expensive product out there and there will be folks that, even withouth fully understanding the technology behind it, will swear on it's quality and say it worth every penny.


----------



## liamstrain

Quote: 





leogodoy said:


> That sentence alone explains everything. People see $$$$ and almost instantly think, nay, they KNOW it relates to quality. This makes the life of companies easier: put a more expensive product out there and there will be folks that, even withouth fully understanding the technology behind it, will swear on it's quality and say it worth every penny.


 
   
  And, because of the way our brains work, to them, it actually might appear to sound better, without actually affecting the sound at all. Expectation bias, is a tricksome thing.


----------



## xnor

This reminds me what I read about delusions. Some criteria for them are:

 certainty (held with absolute conviction)
 incorrigibility (not changeable by compelling counterargument or proof to the contrary)
 impossibility or falsity of content (implausible, bizarre or patently untrue)


----------



## bigshot

I'm not going to get into psychoanalyzing. But I will say this. People put a lot of faith in high end stereo salesmen. They figure that they'll never really fully understand "jitter" and "skin effect"... "but here's a guy who speaks confidently about fancy equipment... I'll pay him to solve all those problems for me." And then the salesman merrily makes mountains out of molehills and sells them a bunch of overpriced junk they really don't need.

The sad thing is, while we like to think that high end audio is the domain of rich guys with money to burn, that really isn't the case. It's people who are excited about great sound that are willing to put a lot into getting it. Unfortunately, they trust someone else to figure it out for them instead of figuring it all out for themselves. If they'd spend a little time trying to understand how it all works, those salesmen wouldn't be able to convince them to buy a bazooka to swat a gnat.


----------



## nick_charles

Quote: 





robertsong said:


> Fair enough. I agree with that. But generally the better more revealing components are more expensive. This type of thing can be (and is) proved with double-blind tests.


 
   
  The esteemed Dr Sean Olive (an occasional poster her) will disagree with you. He has performed many DBTs while heading research at Harman. Among his findings is that when listeners do not know what they are listening to they will tend to prefer the more accurate device regardless of price. When they have clues about the cost and appearance of what they are listening to they will tend to erroneously prefer the expensive/flash looking items even if it is worse quality, it is just basic psychology. In his tests the more accurate item is very seldom the most expensive. In short he finds no reliable correlation between price and quality. And he is not alone here , there are tons of DBTs on the web (sadly few done quite as well as Dr Olive) that reinforce the fact by demonstrating that in DBT the expensive item is seldom differentiated from the less expensive on sound terms alone. In the classic Masters and Clark study many different amps including boutique monoblock tube amps and a cheapo Pioneer receiver were pitted against each other. In the sighted tests audiophiles easily detected differences and described them in great detail. When the study moved to the DBT stage these obvious differences vanished like Brigadoon. You can find numerous cases of testers pretending to swap items such as leads and cables leading to listeners describing non-existent differences.
   
  As for USB cables in particular there have been zero verifiable properly conducted DBTs that have indicated any audible difference between *properly functioning* USB cables. I'm sure one can find plenty of dog and pony shows but here these do not count.


----------



## Mambosenior

Is this claim by a USB cable manufacturer really possible? If it is, how does it equal better sound?

"(our cable)...provides precisely balanced 90-ohm impedance, for performance *that far exceeds the official USB 2.0 High Speed specification*."


----------



## uchihaitachi

Quote: 





mambosenior said:


> Is this claim by a USB cable manufacturer really possible? If it is, how does it equal better sound?
> 
> "(our cable)...provides precisely balanced 90-ohm impedance, for performance *that far exceeds the official USB 2.0 High Speed specification*."


 
  Nice Rachmaninoff picture. 
   
  We live underground. We speak with our hands. We wear the earplugs all our lives.

 PLEASE! You must listen! We cannot maintain the link for long... I will type as fast as I can.

 DO NOT USE AUDIOPHILE USB CABLES!

 We were fools, fools to develop such a thing! Sound was never meant to be this clear, this pure, this... accurate and this unworldly. For a few short days, we marveled. Then the... whispers... began.

 Were they Aramaic? Hyperborean? Some even more ancient tongue, first spoken by elder races under the red light of dying suns far from here? We do not know, but somehow, slowly... we began to UNDERSTAND.

 No, no, please! I don't want to remember! YOU WILL NOT MAKE ME REMEMBER! I saw brave men claw their own eyes out... oh, god, the screaming... the mobs of feral children feasting on corpses, the shadows MOVING, the fires burning in the air! The CHANTING!

 WHY CAN'T I FORGET THE WORDS???

 We live underground. We speak with our hands. We wear the earplugs all our lives.

 Do not use audiophile USB cables!
   
  Moral of the story. Don't use audiophile cables if you believe in them or if you don't


----------



## mikeaj

You know, I'm actually kind of curious what kind of differences in DAC performance you could measure on a bench with some intentionally poor, non-compliant USB cable. If it's bad enough, the system won't work at all. Is there actually a gray area where it'd work but only distort the output appreciably? Seems pretty hard to target the kind of bit error rate and pattern for that to happen.


----------



## liamstrain

Quote: 





mikeaj said:


> You know, I'm actually kind of curious what kind of differences in DAC performance you could measure on a bench with some intentionally poor, non-compliant USB cable. If it's bad enough, the system won't work at all. Is there actually a gray area where it'd work but only distort the output appreciably? Seems pretty hard to target the kind of bit error rate and pattern for that to happen.


 
  As far as I know, you might hear drop-outs and pops, depending on the transfer type. But no distortion, or other muddying or anything.


----------



## mikeaj

http://www.beyondlogic.org/usbnutshell/usb4.shtml
   
  Okay, so for isochronous, there's still a CRC check to determine correctness (so bits being flipped would be detected), but what's the behavior when the check fails? Interpolation or a drop out? If interpolation, you could call that distortion, in some sense. If a drop out... I guess you could still call it distortion, but it'd usually be more of a click or pop.
   
  For the other modes, what happens if corrections and retransmissions don't happen in time? Buffer underrun -> drop outs? Probably.


----------



## anetode

Quote: 





mambosenior said:


> Is this claim by a USB cable manufacturer really possible? If it is, how does it equal better sound?
> 
> "(our cable)...provides precisely balanced 90-ohm impedance, for performance *that far exceeds the official USB 2.0 High Speed specification*."


 
  That's rich, EIA 364 – 108: 76.5 ohm min, 103.5 ohm max.
   
  Quote: 





mikeaj said:


> You know, I'm actually kind of curious what kind of differences in DAC performance you could measure on a bench with some intentionally poor, non-compliant USB cable. If it's bad enough, the system won't work at all. Is there actually a gray area where it'd work but only distort the output appreciably? Seems pretty hard to target the kind of bit error rate and pattern for that to happen.


 
  You might be able to induce audible jitter with a long enough cable and a poor enough DAC. Host software only limits jitter to +/- one sample and you have a full 1.5 microseconds before the host thinks a device is disconnected.


----------



## 367459

Hi - just recently joined and happened across the audio myths thread and now this one. Love the scientific approach to complement the audio highs. It makes me feel I am getting the bigger picture reading the different points of view. 
   
  I bought my first DAC recently. I have been putting together a system on a tight budget so I went for the new Audio Poutine cDAC+ https://www.facebook.com/AudioPoutine (love it - I will get round to a review one day). However, when I first hooked it up to my PC I could hear the improved audio but it had all sorts of clicks and pops after a while. I played for hours with different USB ports and different USB cables and different media players. I went on the Foobar200 and VLC forums and tried all the different config settings. I was really disappointed and thought it was either the DAC or my PC. I then remembered I had my work laptop at home and tried it on that. It sounded great. No clicks or pops. After more research I went out and bought a cheap ($20) powered USB hub and connected my DAC through that instead of directly into the PC USB ports. It has been perfect ever since. Not a single click or pop. I am guessing I just had too many devices pulling from the PC USB power source?
   
  So I guess this post isn't specifically about different USB cables but this might at least save someone else the hours of troubleshooting I went though...
   
  Thanks for this great forum and all the lively posts.
  Andy


----------



## noahbickart

I have a usb keyboard. I used to connect it to my computer with a stock usb cable. On a whim I decided to use this cable instead: 
 http://www.audioadvisor.com/prodinfo.asp?number=AQMUSBDIA%20.75
  
 It costs a mere $548 dollars, which, given that I have about $2000 in my computer, seems like a good deal.
  
 Wow! The difference in my typing is amazing!
 My nouns and adjectives agree with more precision!
 My verbs stand out with greater action, and my nouns are free from hash and jitter.
 The words I write have better flow and pace.
  
 Anyone who can't tell the difference must not have golden ears. A better usb cable makes *anyone* a better writer.


----------



## Greenleaf7

noahbickart said:


> I have a usb keyboard. I used to connect it to my computer with a stock usb cable. On a whim I decided to use this cable instead:
> 
> 
> http://www.audioadvisor.com/prodinfo.asp?number=AQMUSBDIA%20.75
> ...




I absolutely agree. I just upgraded my printer USB cable to a printerphile USB cable. Now the colors are much more vivid and the pictures seem much more alive. My next upgrade will be the power supply cable.


----------



## noahbickart

Quote: 





greenleaf7 said:


> I absolutely agree. I just upgraded my printer USB cable to a printerphile USB cable. Now the colors are much more vivid and the pictures seem much more alive. My next upgrade will be the power supply cable.


 
  A skeptic once tried to prove with a light meter that the colors were the precisely the same and that my head was playing tricks on me (lol), but I suspect that because his test contradicted my subjective experience, there must be something wrong with his test. 
   
  After all, I *feel* that there is a difference. It is worth about $500 to me, and I won't let anyone tell me otherwise.


----------



## Greenleaf7

Quote: 





noahbickart said:


> A skeptic once tried to prove with a light meter that the colors were the precisely the same and that my head was playing tricks on me (lol), but I suspect that because his test contradicted my subjective experience, there must be something wrong with his test.
> 
> After all, I *feel* that there is a difference. It is worth about $500 to me, and I won't let anyone tell me otherwise.


 
  I never trust the equipment, I believe that they're often inaccurate and so i choose to hold my ears in much higher regard. I mean, why bother upgrading your headphones when a simple cable upgrade will offer a much improved sound quality? 
   
  This is the next upgrade i'm planning on getting for my printer
http://www.shunyata.com/Content/products-ZitronAna.html
   
  It claims to dramatically improves peak-current transfer and minimizes distortion between component power supplies and their power source. Although it looks akin to my garden hose, I'm convinced that the improvements will get rid of any nasty artifacts that might appear  my when using the stock power cord. I expect nothing short of a drastic improvement in print quality.


----------



## noahbickart

That's a low-fi printer rig.
   
  You won't understand anything on a printed page until you run your printer off of battery power.
   
  I also place my printer on maple blocks to spiritually isolate the printer from unwanted resonances
   
  http://mapleshadestore.com/feedback_mapleshadeplatforms.php


----------



## xnor

Quote: 





noahbickart said:


> After all, I *feel* that there is a difference. It is worth about $500 to me, and I won't let anyone tell me otherwise.


 
  To such persons you can say that reality doesn't care how they feel.
   
  For example, our eye has blind spots. Just because the white dot disappears for you doesn't mean it disappears from the static image -- in reality it's still there.


----------



## drez

You should see their usb cable (mapleshade). Very clearly out of spec, funny thing is some tried using two of them with a usb powered hub but the signal was so bad the connection wouldn't work. Someone mentioned it earlier but I do wonder how many audiophile cables have actual undergone usb certification.

Personally I am not a consistent objectivist, I believe that digital cable performance matters, just that their performance is purely a technical matter. I believe the DAC doesnt care what the cable is made of, as long as it measures well and does it's job of transferring a square wave with minimal rounding.

I have identified a trend with clearly out of spec cables. The sound quality descriptions tend to point to "relaxed" or "warm" sound qualities. Less suspect cables eg from Audioquest and Wireworld tend to be described as "faster" sounding. Strange thing is lots of audiophiles seem to prefer the warmer sound so will rank cables which are clearly bad digital cables, very highly. So many audiophiles are paying thousands for cables that likely perform badly... 

I should also mention that I cant guarantee (let alone prove) that Wireworld and Audiqoest perform any better that a to-spec USB cable, just their designs are more sensible than some others I have seen. These examples were given purely for the sake of my argument.

These subjective anectdotes are hardly reliable "data" or "evidence", just trends I have observed. If anyone is interested in trying out or researching USB cables, I hope my observations might be useful.


----------



## robertsong

Quote: 





noahbickart said:


> I have a usb keyboard. I used to connect it to my computer with a stock usb cable. On a whim I decided to use this cable instead:
> http://www.audioadvisor.com/prodinfo.asp?number=AQMUSBDIA%20.75
> 
> It costs a mere $548 dollars, which, given that I have about $2000 in my computer, seems like a good deal.
> ...


 
   
  Hi. Here is where your analogy fails. You don't understand the difference b/t data packets and an audio stream. Here's  Wireworld's explanation:
   
   
  There is a fundamental difference between the transfer of computer data and 
	

	
	
		
		

		
			




 digital audio signals. *Computers are able to transfer digital data without loss, because the data moves in the robust form of blocks, which do not depend on specific timing between the sending and receiving devices. However, digital audio signals are continuous streams of data, which are quite fragile, since the digital processor must remain perfectly locked onto the timing of the signal to avoid data losses.*
  The Limitations of digital audio processors and cables create timing errors known as jitter, which remove portions of the audio signal and replace them with noise and distortion. Cables tend to round off the square waveforms of the signal, making them less clear to the processor, thus increasing jitter. This rounding effect varies greatly among cables and a truly superior digital audio cable can make great improvements in sound quality.
  WireWorld digital audio cables utilize unique designs specifically developed to minimize jitter by providing sharper, cleaner leading edges on the digital waveform. At each price level, they provide the lowest jitter available, producing distinct improvements in clarity, image focus, smoothness and dynamic range.
  WireWorld USB cables feature a unique flat design that allows it to function over significantly longer runs than conventional USB cables and provides improved sound quality in media server, PC audio, and other digital music applications.

 Our unique flat cable design not only improves performance, but it allows you to connect digital music devices over longer distances – for instance, a laptop PC across the room from the home theater system.
* All models exceed the USB2.0 High Speed specifications.*
  USB cables product sheet: CLICK HERE
   
   
  And here is a Double Blind Test that refutes the "all usb cables sound the same" nonsense.
   
  http://www.crystalcable.com/CMS/ckfinder/userfiles/files/Hi-Fi+%20februari%202012%20Crystal%20Cable%20USB.pdf
   
   
  And here is some information on a more recent double blind test. This one may be the first to include jitter measurements.
   
   
  http://www.head-fi.org/t/664972/hifi-news-usb-cable-shootout
   
   
  Noticing a trend here? It must all be part of a grand conspiracy for audiophile companies to scam people into forking over some extra cash. Riiiiiiight.


----------



## robertsong

Quote: 





drez said:


> These subjective anectdotes are hardly reliable "data" or "evidence", just trends I have observed. If anyone is interested in trying out or researching USB cables, I hope my observations might be useful.


 
   
   
  If subjective opinions mean nothing to you, and you can't trust your own ears, then how exactly do you choose a piece of audio equipment??
   
  What are these "objective" measurements you go by?  Do you just throw a dart at whatever looks good to you?
   
  Are DBT's useless to you as well?


----------



## mikeaj

Quote: 





robertsong said:


> And here is a Double Blind Test that refutes the "all usb cables sound the same" nonsense.
> 
> http://www.crystalcable.com/CMS/ckfinder/userfiles/files/Hi-Fi+%20februari%202012%20Crystal%20Cable%20USB.pdf


 
   
  I don't mean to nitpick when there are bigger issues at play, but there is a very important correction to make: that is *single* blind, not double blind.
   
  But more importantly, there is no mention of statistical analysis or even rudimentary experimental design. How consistent is "remarkably consistent"? Same for the other link—apparently no serious discussion of listening results.
   
   
   
  Also... you do realize that even for audio there's a buffer involved on the USB receiver's side, and that the USB signaling itself is not driving the DAC?


----------



## noahbickart

Digital audio signals _are_ computer data. 1010111010101010101010 = 1010111010101010101010.
  
 Digital audio isn't any more "fragile" than any other digital information. 
  
 Wireworld sells USB cables making them far from unbiased.
  
 USB and other Digital Cables either meet the spec that equipment using that Spec requires or they don't.
  
 You may feel better about your listening experience using a $500 digital cable- but it doesn't sound different.
  Quote: 





robertsong said:


> Hi. Here is where your analogy fails. You don't understand the difference b/t data packets and an audio stream. Here's  Wireworld's explanation:
> 
> 
> There is a fundamental difference between the transfer of computer data and
> ...


----------



## robertsong

Quote: 





noahbickart said:


> Digital audio signals _are_ computer data. 1010111010101010101010 = 1010111010101010101010.
> 
> Digital audio isn't any more "fragile" than any other digital information.


 
   
   
  Nope, the difference is how the data is sent and how it is received and interpreted by the device. Blocks of data vs. a continuous stream. Audio receivers and data receivers do not work the same way. You are going to have to ask legitimate audio engineer for a more concise explanation. Unfortunatley no one posting on the "sound science" forum has those qualifications.  I can understand why not.
   
  Btw, doesn't the Schiit engineer post on head-fi? If you really need a better explanation, maybe try PM'ing him.


----------



## robertsong

Quote: 





> You may feel better about your listening experience using a $500 digital cable- but it doesn't sound different.


 
   
   
  There are subtle differences between audio components/cables, and there are some not so subtle differences. Just to be clear I heard differences between the Lacie Flat and Belkin gold cables as well. I'll leave it at that.


----------



## WALL-E

Well said *drez*!  I came to the same conclusion, experimenting with USB cables and finally I built my own basing on the Ethernet cable design, since the specification is well documented. http://www.head-fi.org/t/665635/know-how-diy-cable-related-tutorials
   
  Some audio cable company making their "audio grade USB cables" have made claims that may apply to analog signal cables but not for digital data transfer it does not even meet normal commercial standards, unfortunately this is the normal situation with 'audiophile' cables.


----------



## mikeaj

Quote: 





robertsong said:


> Nope, the difference is how the data is sent and how it is received and interpreted by the device. Blocks of data vs. a continuous stream. Audio receivers and data receivers do not work the same way. You are going to have to ask legitimate audio engineer for a more concise explanation. Unfortunatley no one posting on the "sound science" forum has those qualifications.  I can understand why not.
> 
> Btw, doesn't the Schiit engineer post on head-fi? If you really need a better explanation, maybe try PM'ing him.


 
   
  Some audio devices don't use isochronous transfer mode, but all of the transfer modes are still packetized. It's not a continuous stream in that sense. Certainly not a stream in the sense of the timing being important in the way you describe, as there is a buffer and the DAC is not being driven by this "stream". Pretty much, the physical layer should be the same no matter which mode.
   
  Sure, data transfers are bulk transfer mode, which have guarantee of delivery via retransmissions. But base bit error rate of signaling in USB is supposed to be 10^-12 to be standards compliant.


----------



## robertsong

Quote: 





wall-e said:


> Some audio cable company making their "audio grade USB cables" have made claims that may apply to analog signal cables but not for digital data transfer* it does not even meet normal commercial standards*, unfortunately this is the normal situation with 'audiophile' cables.


 
   
   
  On the contrary, I think the vast majority of them claim they do. I know absolutely nothing about this Mapleshade cable and could really care less about it. Out of curiosity how does one go about proving that?


----------



## bigshot

robertsong said:


> Btw, doesn't the (redacted) engineer post on head-fi? If you really need a better explanation, maybe try PM'ing him.




Been there, done that... You aren't going to find many sales reps posting in this forum. They prefer to participate in areas where the folks they are talking to don't really understand what they're talking about and just trust them to be correct. They don't do well in forums like this.

By the way, that sales literature you posted totally avoided the concept of buffering. Sound isn't streamed across cables. It's transferred in chunks and reassembled in a buffer before playing. That avoids momentary streaming errors.


----------



## robertsong

Quote: 





mikeaj said:


> Some audio devices don't use isochronous transfer mode, but all of the transfer modes are still packetized. It's not a continuous stream in that sense. Certainly not a stream in the sense of the timing being important in the way you describe, as there is a buffer and the DAC is not being driven by this "stream". Pretty much, the physical layer should be the same no matter which mode.
> 
> Sure, data transfers are bulk transfer mode, which have guarantee of delivery via retransmissions. But base bit error rate of signaling in USB is supposed to be 10^-12 to be standards compliant.


 
   
   
  And if the jitter is introduced within the cable itself (let's say from reflections) how does buffer compensate for bits already lossed/damaged?  You also failed to tackle the issue with rise-times and rounded leading edges.


----------



## bigshot

robertsong said:


> Out of curiosity how does one go about proving that?




In order to be certified, they submit their cable to testing to prove it meets USB spec. Many aren't certified. It's the same with power cables. All power cables should be submitted for certification by Underwriters' Laboratories. ("UL Listed") However, many high end cables are jerry rigged affairs made in someone's garage and they don't bother. Unfortunately, if homeowner's insurance finds out that you're using non-UL certified wiring, you might be SOL if you want to collect on a house fire.

Certification matters.


----------



## bigshot

robertsong said:


> And if the jitter is introduced within the cable itself (let's say from reflections) how does buffer compensate for bits already lossed/damaged?  You also failed to tackle the issue with rise-times and rounded leading edges.




How long of a cable are you talking about? 25 feet? 50 feet?


----------



## robertsong

Quote: 





bigshot said:


> Been there, done that... You aren't going to find many sales reps posting in this forum.


 
   
   
  I was talking about the actual engineers not sales reps.


----------



## bigshot

Those engineers are posting in internet forums as sales reps. "member of the trade"


----------



## robertsong

Quote: 





bigshot said:


> How long of a cable are you talking about? 25 feet? 50 feet?


 
   
   
  Nope, how about 2 feet vs. 5 feet.  There's a 1.5m minimum rule determined by a double blind test if you are interested. It concerns jitter caused by the reflections in shorter cables.
   
   
  The  cable length test was also tackled in the test asteroid posted apparently.


----------



## noahbickart

Quote: 





robertsong said:


> Nope, the difference is how the data is sent and how it is received and interpreted by the device. Blocks of data vs. a continuous stream. Audio receivers and data receivers do not work the same way. You are going to have to ask legitimate audio engineer for a more concise explanation. Unfortunatley no one posting on the "sound science" forum has those qualifications.  I can understand why not.
> 
> Btw, doesn't the Schiit engineer post on head-fi? If you really need a better explanation, maybe try PM'ing him.


 
  What you say makes perfect sense, *if* you are using a DAC without a buffer.
   
  Can you name a DAC chip or, for that matter, a USB DAC which doesn't buffer the data?


----------



## bigshot

robertsong said:


> Nope, how about 2 feet vs. 5 feet.  There's a 1.5m minimum rule determined by a double blind test if you are interested. It concerns jitter caused by the reflections in shorter cables




According to USB spec, shorter cables are able to deliver error free data more than fast enough to fill the buffer in the DAC. Then the buffer serves out the data with no jitter.

Excessively long cables would have troubles, but I don't think we're talking about that.


----------



## Greenleaf7

Quote: 





bigshot said:


> Those engineers are posting in internet forums as sales reps. "member of the trade"


 
  I couldn't agree more!


----------



## robertsong

*[size=x-small]Difference between Audio Streaming and other data transfers[/size]*
  [size=x-small]I am often asked how does digital streaming audio and data transmissions to disks or printers differ. It is after-all only data being transferred from one point to another. Actually, there is more to it than this. Digital audio streaming is a "real-time" process, meaning that the actual timing of the transfer of each data bit from the source to the D/A converter is important and must be as precise as possible. Data transfers to disk or a printer are not real-time because there is no urgency for the data to arrive at the printer or disk to prevent errors from happening. The data arrives whenever it does and then the device does its job with the data, either writing it to the disk or storing it in a print buffer. If the data does not arrive in time to be written on a particular sector of a disk, the hardware just waits for the disk to rotate again. Streaming audio data on the other hand must arrive at precise time intervals in order that the D/A device create an accurate representation of the original recording. If it does not "keep-up" the pace, then dropouts will occur and the D/A converter will fall out of sync. The clock that moves the data into the D/A cannot be missing any "ticks" and each tick must be precisely placed in time. The audio data transfer must include both 1) accurate data and 2) accurate timing, whereas non-real-time transfers only require accurate data.[/size]
   
   
*[size=x-small]8. Digital Cables[/size]*
  [size=x-small]Cables don't actively add jitter to the signal, however they can slow the signal transitions or "edges". When the edges are slowed, the receiver or buffer at the cable destination is less likely to detect the transition at the correct time with certainty, which results in jitter.[/size]
   
   
  http://www.positive-feedback.com/Issue43/jitter.htm


----------



## jaddie

Quote: 





robertsong said:


> And here is some information on a more recent double blind test. This one may be the first to include jitter measurements.
> 
> 
> http://www.head-fi.org/t/664972/hifi-news-usb-cable-shootout


 
   As noted in the thread, it wasn't double-blind.
  Quote:



> And here is a Double Blind Test that refutes the "all usb cables sound the same" nonsense.
> 
> http://www.crystalcable.com/CMS/ckfinder/userfiles/files/Hi-Fi+%20februari%202012%20Crystal%20Cable%20USB.pdf


 
  The test wasn't double-blind, there's no data on how the switching was accomplished, and with 20 combinations and three listeners, to gather data from 20 tests (they probably didn't, but don't say) each would have taken much longer than a Saturday afternoon to gather enough data to be statistically meaningful.


----------



## robertsong

*[size=x-small]Some History[/size]*
  [size=x-small]Jitter has been with us since the inception of the CD format by Sony and Philips in 1982. It is a pervasive problem with all digital audio. It has prevented digital audio, both CD's and computer-driven-audio from competing with good vinyl and tape for decades. It is only recently that manufacturers have become aware of the problem and developed improved chips and systems to deal with jitter.[/size]
*[size=x-small]What is Jitter?[/size]*
  [size=x-small]Technically, playback jitter is the inaccuracy in the timing of the "ticks" of the clock that transfers the samples of digital data into the D/A converter chip. To move data in a digital system from one point to another, it is usually clocked. In order for the D/A conversion to work, a new data word must be presented to the D/A converter periodically, or at a fixed frequency. The system clock or clocks do this. In an ideal world, each transfer of data to the D/A on a clock tick should occur at a precise point in time. If some data transfers occur a tiny bit early and others occur a tiny bit late, this is jitter. It is kind of like a timepiece that ticks away the seconds, where the duration of each second is not exactly a second, but over a large number of seconds, the timepiece is still telling accurate time. The duration of some second intervals is slightly short and other intervals are slightly long, but the average of all of them still gives accurate time. Likewise, when digital audio is played-back, the clock "ticks" that present each new data word to the D/A converter can have shorter and longer intervals from one tick to the next. The effect of this jitter on the D/A conversion and the analog waveform is frequency modulation, the same type of modulation that is used for FM radio. The difference is that with FM radio, the carrier frequency is fixed and the jitter is the music signal that is modulating the frequency of the carrier wave. With digital audio, the carrier is the music and the jitter is the modulation. This makes it a much more complex signal than even FM radio. The jitter associated with digital streaming audio is usually a mix of non-correlated and correlated jitter, correlated being that jitter that is somehow related to the music data or waveform and uncorrelated usually being random jitter. Jitter has both an amplitude and a frequency component. We will later discuss which of these I believe is more important.[/size]


----------



## robertsong

Quote: 





bigshot said:


> According to USB spec, shorter cables are able to deliver error free data more than fast enough to fill the buffer in the DAC. Then the buffer serves out the data with no jitter.
> 
> Excessively long cables would have troubles, but I don't think we're talking about that.


 
   
   
  Can I show you you white-paper on that or would that be an utter waste of my time. I have plenty of other things to do today....believe me.


----------



## bigshot

robertsong said:


> Cables don't actively add jitter to the signal, however they can slow the signal transitions or "edges". When the edges are slowed, the receiver or buffer at the cable destination is less likely to detect the transition at the correct time with certainty, which results in jitter.


Can someone please explain to me how binary data can get "rounded corners" like that?

As I understand it, playback from a buffer guarantees that the data is run through the DAC with correct timing. No jitter. If data is being changed because it's being transmitted through the cable incorrectly, that's data corruption, not jitter. Data corruption is easy to measure... if it exists.


----------



## bigshot

robertsong said:


> Can I show you you white-paper on that or would that be an utter waste of my time. I have plenty of other things to do today....believe me.




You actually have reports from independent studies? Up to now, you've only been cutting and pasting sales literature. If you have something by the AES or similar, I'd be very interested in seeing it.


----------



## robertsong

Quote: 





bigshot said:


> Can someone please explain to me how binary data can get "rounded corners" like that?
> 
> As I understand it, playback from a buffer guarantees that the data is run through the DAC with correct timing. No jitter. If data is being changed because it's being transmitted through the cable incorrectly, that's data corruption, not jitter. Data corruption is easy to measure... if it exists.


 
   
   
  Utter nonsense. Why do you suppose so many DACS have a night and day sound difference? By far the the biggest difference is_ in fact _jitter.


----------



## robertsong

Quote: 





bigshot said:


> You actually have reports from independent studies? Up to now, you've only been cutting and pasting sales literature. If you have something by the AES or similar, I'd be very interested in seeing it.


 
   
   
  White papers and sales literature are hardly the same thing.
   
  I'm out of here for now. If I get really really bored someday I'll come back and pummel you with some more evidence. As for myself I have read enough science.


----------



## bigshot

If two pieces of digital equipment sound very different, it's most likely because the frequency response of one or the other of them is colored. Coloration is more common in high end equipment than it is in midrange. Personally, if I determined that a DAC, DAP or CD player was coloring the sound and there was a night and day difference, I would return it as defective. The whole point of digital audio is that it is calibrated to transparency.

Adieu for now. We're always here interested in learning. Let us know when you're open to learning too.


----------



## liamstrain

Quote: 





robertsong said:


> 1. Utter nonsense. Why do you suppose so many DACS have a night and day sound difference?
> 
> 2. By far the the biggest difference is_ in fact _jitter.
> 
> 3. If I get really really bored someday I'll come back and pummel you with some more evidence.


 
   
  1. This has not been my experience. Nearly every DAC I have ever used, that did not deliberately try to color the sound using modded chips, has been pretty nearly transparent. 
   
  2. Jitter in the audible range is extremely hard to induce with any competent equipment. Do you have any data to support this assertion?
   
  3. Please do. It would be a welcome change from what you have been providing so far.


----------



## xnor

Quote: 





drez said:


> I have identified a trend with clearly out of spec cables. The sound quality descriptions tend to point to "relaxed" or "warm" sound qualities. Less suspect cables eg from Audioquest and Wireworld tend to be described as "faster" sounding. Strange thing is lots of audiophiles seem to prefer the warmer sound so will rank cables which are clearly bad digital cables, very highly. So many audiophiles are paying thousands for cables that likely perform badly...
> [...]
> 
> These subjective anectdotes are hardly reliable "data" or "evidence", just trends I have observed. If anyone is interested in trying out or researching USB cables, I hope my observations might be useful.


 
  I think that's a trend not only in the realm of digital audio cables, but all kinds of audio cables, rolled-off DACs, non-oversampling DACs, amps with high output impedance or distortion levels ... up to DIYers swapping op-amps resulting in instability.
   
  Quote: 





robertsong said:


> If subjective opinions mean nothing to you, and you can't trust your own ears, then how exactly do you choose a piece of audio equipment??
> 
> What are these "objective" measurements you go by?  Do you just throw a dart at whatever looks good to you?
> 
> Are DBT's useless to you as well?


 
  There's a difference between anecdotes and DBTs. There's a difference between using all your senses or trusting your ears only.
   
  Quote: 





robertsong said:


> Nope, the difference is how the data is sent and how it is received and interpreted by the device. Blocks of data vs. a continuous stream. Audio receivers and data receivers do not work the same way. You are going to have to ask legitimate audio engineer for a more concise explanation. Unfortunatley no one posting on the "sound science" forum has those qualifications.  I can understand why not.


 
  Lots of (wrong) assumptions.
  Those transfers are done every millisecond so each frame (yeah, even audio "streams" are transferred in frames) contains a millisecond worth of audio data. Also isochronous transfers have guaranteed bandwidth.
  The difference to bulk transfers (like external HDDs use) is that bulk transfers don't guarantee bandwidth or minimum latency, but guarantee delivery.
   
   
  Quote: 





robertsong said:


> There are subtle differences between audio components/cables, and there are some not so subtle differences. Just to be clear I heard differences between the Lacie Flat and Belkin gold cables as well. I'll leave it at that.


 
  That's exactly the kind of anecdote drez described as "hardly reliable 'data' or 'evidence'".


----------



## mikeaj

Quote: 





robertsong said:


> And if the jitter is introduced within the cable itself (let's say from reflections) how does buffer compensate for bits already lossed/damaged?  You also failed to tackle the issue with rise-times and rounded leading edges.


 
   
  In systems with retransmission, errors are detected and corrected eventually. For isochronous mode, there's no error correction in any sense... just error detection and presumably some kind of fallback scheme when things go wrong, so yes, it'd be damaged for good. That said, bit errors are very unlikely. Like 10^-12 unlikely—or at least, that's the spec I see when searching around, though for USB 3.0 specifically it seems.
   
  You don't need the cleanest-ever eye diagram, perfect rise and fall times, completely noiseless environments to get the vast majority of bits through correctly, like above 99.9999999999% of them (referencing above 10^-12).
   
   
  Quote: 





robertsong said:


> *[size=x-small]Some History[/size]*
> [size=x-small]Jitter has been with us since the inception of the CD format by Sony and Philips in 1982. It is a pervasive problem with all digital audio. It has prevented digital audio, both CD's and computer-driven-audio from competing with good vinyl and tape for decades. It is only recently that manufacturers have become aware of the problem and developed improved chips and systems to deal with jitter.[/size]
> *[size=x-small]What is Jitter?[/size]*
> [size=x-small]Technically, playback jitter is the inaccuracy in the timing of the "ticks" of the clock that transfers the samples of digital data into the D/A converter chip. To move data in a digital system from one point to another, it is usually clocked. In order for the D/A conversion to work, a new data word must be presented to the D/A converter periodically, or at a fixed frequency. The system clock or clocks do this. In an ideal world, each transfer of data to the D/A on a clock tick should occur at a precise point in time. If some data transfers occur a tiny bit early and others occur a tiny bit late, this is jitter. It is kind of like a timepiece that ticks away the seconds, where the duration of each second is not exactly a second, but over a large number of seconds, the timepiece is still telling accurate time. The duration of some second intervals is slightly short and other intervals are slightly long, but the average of all of them still gives accurate time. Likewise, when digital audio is played-back, the clock "ticks" that present each new data word to the D/A converter can have shorter and longer intervals from one tick to the next. The effect of this jitter on the D/A conversion and the analog waveform is frequency modulation, the same type of modulation that is used for FM radio. The difference is that with FM radio, the carrier frequency is fixed and the jitter is the music signal that is modulating the frequency of the carrier wave. With digital audio, the carrier is the music and the jitter is the modulation. This makes it a much more complex signal than even FM radio. The jitter associated with digital streaming audio is usually a mix of non-correlated and correlated jitter, correlated being that jitter that is somehow related to the music data or waveform and uncorrelated usually being random jitter. Jitter has both an amplitude and a frequency component. We will later discuss which of these I believe is more important.[/size]


 
   
  Yes, jitter on the D/A process matters to some extent, though usually not really. But how is that related to timing issues on the USB transmission itself? Like I keep saying the USB communications is a separate process than the D/A. Except in relatively cheap stuff, the USB receiver is even a separate chip than the DAC.
   
  Any "papers" not by people selling cables? Or papers with actual data by anyone?


----------



## uchihaitachi

Quote: 





mikeaj said:


> In systems with retransmission, errors are detected and corrected eventually. For isochronous mode, there's no error correction in any sense... just error detection and presumably some kind of fallback scheme when things go wrong, so yes, it'd be damaged for good. That said, bit errors are very unlikely. Like 10^-12 unlikely—or at least, that's the spec I see when searching around, though for USB 3.0 specifically it seems.
> 
> You don't need the cleanest-ever eye diagram, perfect rise and fall times, completely noiseless environments to get the vast majority of bits through correctly, like above 99.9999999999% of them (referencing above 10^-12).
> 
> ...


 
  I am still incredulous. He is not serious is he?!


----------



## anetode

Quote: 





robertsong said:


> Btw, doesn't the Schiit engineer post on head-fi? If you really need a better explanation, maybe try PM'ing him.


 
  Copy for Schiit-brand cables:
   
  Quote: 





> *Beyond Just Technology: SuperUltraHyperTechnology*
> PYST cables are made from only the finest 6-nines Unobtanium™ alloy, molecularly assembled in our Alternate Universe™ reality-distortion tesseract field , using a secret geometry reverse-engineered from crashed UFOs, painstakingly smuggled out of Area 51 by deep-cover operatives. Performance is further enhanced by the use of a QuantConnect™ quantum-entangled pair of transmission interfaces, held at absolute zero by our exclusive Stasis Field™ technology. The cables are then wrapped in NanoAeroCap™, a nanotechnology-enabled aerogel anti-capacitance insulation system, featuring Fractal Interleaved Geometry™ to create negative inductance for maximum audio transmission quality.
> 
> Or, er, well . . . again, no. These are nice, high-quality cables, with solid, reliable connectors. That’s it. Hope you like them!


----------



## anetode

Quote: 





robertsong said:


> And if the jitter is introduced within the cable itself (let's say from reflections) how does buffer compensate for bits already lossed/damaged?  You also failed to tackle the issue with rise-times and rounded leading edges.


 

   
   
  Quote: 





robertsong said:


> *[size=x-small]Some History[/size]*
> [size=x-small]Jitter has been with us since the inception of the CD format by Sony and Philips in 1982. [...][/size]


 
  Misleading from the very first sentence. Jitter existed, was known of and studied well prior to 1982. Minor error and more of a stylistic choice for an introduction, sure, but when you start from a false or misleading premise...


----------



## uchihaitachi

Quote: 





anetode said:


> Copy for Schiit-brand cables:


 
  +1 for creativity!


----------



## Steve Eddy

Quote: 





anetode said:


> Misleading from the very first sentence. Jitter existed, was known of and studied well prior to 1982.


 
   
  Yeah. Digital PCM was first conceived at Bell Labs back in the 40's and I'm sure that jitter was anticipated even back then, though for telephone transmissions it probably wasn't a high priority.
   
  se


----------



## nick_charles

Quote: 





anetode said:


> Misleading from the very first sentence. Jitter existed, was known of and studied well prior to 1982. Minor error and more of a stylistic choice for an introduction, sure, but when you start from a false or misleading premise...


 
   
  He is quoting Steve Nugent, one of the most vocal Jitter-worriers. To date not one credible study, and this goes all the way back to the BBC in the 1970s, has suggested that anybody can reliably detect Jitter at the levels and of the modes found in even low end commercial digital components is in any way audible. The Jitter killing gang try to bamboozle us with super low Jitter numbers created by using their generally expensive jitter-killing devices but not one of these manufacturers including Empirical Audio (and I have asked Steve about this several times) can provide anything but anecdotes and dog and pony shows to prove that the jitter they are killing was audible in the first place. Steve himself despite claiming not only to be able to detect 2ps of signal-correlated jitter but the differences between 2ps with different spectra took part in an internet forum where jittered samples were presented with jitter ranging from zero added jitter to 10ns to 30ns to 100ns added jitter and failed miserably to correctly identify which was which. I on the other hand was able to identify them perfectly, of course I cheated and ran the samples thru a spectral analysis exported them to an excel workbook and just looked at the numbers. In full disclosure one person did correctly detect the 10ns sample once, but this while notable was not achieved by anyone else and few devices have that much jitter. In fact I have only found 2 and one of these was the execrable McIntosh MS750 Music Server (http://www.stereophile.com/content/mcintosh-ms750-music-server-measurements) which bizarrely was subjectively quite well regarded. Aside from this abomination you will struggle to find components whose jitter levels are verifiably audible.


----------



## anetode

So it's from Positive Feedback. I'm not a huge fan of the counterprogramming of the sorts of "Empirical" Audio's Nugent relying on untested models of jitter audibility instead of actual listening tests. Nor of the FAQ outlining relatively uncontroversial (if dry) technical assertions only to depend on three cherry-picked citations when mentioning the controversial deal clincher.


----------



## White Lotus

I can't tell if we are all being trolled or not.


----------



## bigshot

I don't think so. There are a lot of people who think the hobby is all about shopping. They learn everything they know from salesmen and manufacturers' pitch sheets. They fix things by buying replacements without ever knowing what's really wrong.

When that's all you know, and you invest your faith and hard earned dollars into believing it's true, people who give you the straight dope seem crazy. It just shows how far from reality high end audio has gotten.


----------



## dleblanc343

I had compared three usb cables about a year ago and believe I posted my results on this exact thread (other wise I forget why I subscribed to it in the first place).
   
  I compared a standard HP printer usb cable, my audioquest carbon (which I recently upgraded) and the Tellurium Q silver usb cable. I remember being impressed by the tellurium, and also guessed it on a double blind test 4 out of 6 times between my brother and friend swapping cables randomly. Now, of course that's not 6 out of 6, but I was convinced it seemed less veiled. Another weird observation I made was that the audioquest carbon sounded warmer than the stock usb cable, with more midbass presence. We're talking very minute differences, but still what I remember and noted. Also, when using the printer usb and audioquest carbon, I remember my music clipping 2-3 times per high res song (24 bit 192khz and up); whereas the tellurium q only clipped once in about an hour of listening one evening. This is what probably caused the bias in thinking that usb does make a difference; but it can also be pure coincidence.
   
  And yes, I work in retail and I am a salesperson; but I'm one of the honest ones as I was suckered into this hobby myself 
	

	
	
		
		

		
			





. I've always been used as a guinea pig for analyzing tracks as I have the best ears between my friends and co-workers. They don't often capture small intricate musical passages or artifacts, and I often pick them up and tell them what to listen for; it's then that they would hear them. I felt the need to try it out for myself at the time and did so. I can't say with 100% certainty if usb cables can sound different, but I am more inclined to say yes. As soon as you have different materials involved, you should expect change (not necessarily improvements).
   
  I recently tried the audioquest diamond and ordered one as I felt it simply sounded more "correct" and transparent. The DBS system may help with noise floor as advertised, but I can't confirm. My McIntosh MC225 with the NAD M51 does seem to have less of a noise floor; but I also got new tube dampers. The HD800's on my rig do reveal a lot so there is less of a noise floor.
   
  Still, it's so difficult to judge, that I say it's simply not worth it for most to break their heads over it. For my system and the money I put into it, I think it's very well worth it. But if you don't have a "hi-fi" system; it's not worth your time, money and paranoia.


----------



## uchihaitachi

Quote: 





dleblanc343 said:


> I had compared three usb cables about a year ago and believe I posted my results on this exact thread (other wise I forget why I subscribed to it in the first place).
> 
> I compared a standard HP printer usb cable, my audioquest carbon (which I recently upgraded) and the Tellurium Q silver usb cable. I remember being impressed by the tellurium, and also guessed it on a double blind test 4 out of 6 times between my brother and friend swapping cables randomly. Now, of course that's not 6 out of 6, but I was convinced it seemed less veiled. Another weird observation I made was that the audioquest carbon sounded warmer than the stock usb cable, with more midbass presence. We're talking very minute differences, but still what I remember and noted. Also, when using the printer usb and audioquest carbon, I remember my music clipping 2-3 times per high res song (24 bit 192khz and up); whereas the tellurium q only clipped once in about an hour of listening one evening. This is what probably caused the bias in thinking that usb does make a difference; but it can also be pure coincidence.
> 
> ...


 
  4 out of six is hardly statistically significant... Why not retry the test but do 100 trials and if you are significant to a 5% level of significance, we may be onto something here .


----------



## leogodoy

I see a trend where people believe expensive cables "only make a difference" as a testament to their expensive equipment and outstanding ears. "Of course they have to have an effect on sound, at least for my perfect and refined ears and in conjunction with my multi thousand dollar rig". The argument for cables, then, is not anymore a defense of the product, but a form of self praise.


----------



## uchihaitachi

Quote: 





leogodoy said:


> I see a trend where people believe expensive cables "only make a difference" as a testament to their expensive equipment and outstanding ears. "Of course they have to have an effect on sound, at least for my perfect and refined ears and in conjunction with my multi thousand dollar rig". The argument for cables, then, is not anymore a defense of the product, but a form of self praise.


 
  I have never thought of it that way. Expensive cables=golden ears=bragging rights. Mmm.... Becomes more fascinating day by day.


----------



## dleblanc343

Quote: 





uchihaitachi said:


> 4 out of six is hardly statistically significant... Why not retry the test but do 100 trials and if you are significant to a 5% level of significance, we may be onto something here .


 
  Indeed, but that would take a long time! those 6 tries took about 20 minutes total. I should also redo this test but swap cables quickly. Not many people are willing to participate in such DBT activities lol.
   
  Also, in no ways am I showing off my gear or my hearing abilities (I hear up to 17 khz, nothing outstanding, but I am an analytical listener). There is no self-praise in my critique, I'm _just stating the facts and background of my experiences as clearly as possible_. Fyi, there's nothing to be proud of in spending multi-thousands on audio!
   
  At the end of the day, I did this for myself. The conclusion of my tests are of no value to any reader out there; zero. I recommend people respect other head-fiers' opinions and trials and have some fun trying to figure it out themselves. Hearing for yourself is always more fun, if achievable, than speculating and going into technicality and theory. Believe it or don't believe it, we don't care about your opinion!


----------



## esldude

Mr. Charles,
   
  How dare you bring facts into this.  People like Steve, regularly trumpet how the jitter is most noticeable at low frequencies.  Yet normal technical knowledge suggests the effects of jitter will be most prominent at the highest frequencies.  And then here you are doubting someone able to identify 2 pico-second differences in random timing.  That is only 25 thousandths of an inch at the speed of light in most cabling.  Why would you even question such perception?  I would think anyone can audibly hear differences like that at the speed of light.  Yet do you really doubt it?  Are you possibly even serious about this? 
   
   
   
   
  Yes, I am afraid my post is somewhat sarcastic.  Please excuse me.  There is after all money to be made here.  Nothing else could possibly matter.  Nothing I tell you.


----------



## uchihaitachi

Quote: 





esldude said:


> Mr. Charles,
> 
> How dare you bring facts into this.  People like Steve, regularly trumpet how the jitter is most noticeable at low frequencies.  Yet normal technical knowledge suggests the effects of jitter will be most prominent at the highest frequencies.  And then here you are doubting someone able to identify 2 pico-second differences in random timing.  That is only 25 thousandths of an inch at the speed of light in most cabling.  Why would you even question such perception?  I would think anyone can audibly hear differences like that at the speed of light.  Yet do you really doubt it?  Are you possibly even serious about this?
> 
> ...


 
  Who are you referring to by Steve?


----------



## ab initio

Quote: 





uchihaitachi said:


> Who are you referring to by Steve?


 

 The guy from Emperical Audio I think. He's all over the jitter discussions elsewhere in the forums. My understanding is that the guy has such outstanding hearing, that he's got a premier audio system out of necessity, because anything less than femtosecond jitter would sound to him the way nails on a chalkboard do to mortals.


----------



## uchihaitachi

Quote: 





ab initio said:


> The guy from Emperical Audio I think. He's all over the jitter discussions elsewhere in the forums. My understanding is that the guy has such outstanding hearing, that he's got a premier audio system out of necessity, because anything less than femtosecond jitter would sound to him the way nails on a chalkboard do to mortals.


 
  I see, he must be an owl or a bat.


----------



## ab initio

Quote: 





uchihaitachi said:


> I see, he must be an owl or a bat.


 

 I work with bats. I'd be very curious to see a head transfer function for some of the ones with freaky ears and noses! 
  Despite their ears, I think femtoseconds are still too fleeting for them. Humans can learn to echolocate too....


----------



## noahbickart

Quote: 





dleblanc343 said:


> I compared a standard HP printer usb cable, my audioquest carbon (which I recently upgraded) and the Tellurium Q silver usb cable. I remember being impressed by the tellurium, and also guessed it on a double blind test 4 out of 6 times between my brother and friend swapping cables randomly. Now, of course that's not 6 out of 6, but I was convinced it seemed less veiled.


 
  Even according to your position, a full on third of the times you spent concentrating on *nothing* else, you couldn't distinguish between a free product and a ~$300 product.
   
  And you are proud of that?


----------



## uchihaitachi

Quote: 





ab initio said:


> I work with bats. I'd be very curious to see a head transfer function for some of the ones with freaky ears and noses!
> Despite their ears, I think femtoseconds are still too fleeting for them. Humans can learn to echolocate too....


 
  That is quite extraordinary. What do you do with bats?


----------



## dleblanc343

Quote: 





noahbickart said:


> Even according to your position, a full on third of the times you spent concentrating on *nothing* else, you couldn't distinguish between a free product and a ~$300 product.
> 
> And you are proud of that?


 
  All cables were in-store product, and I don't see what you point on being proud of it is all about. The cables I own cost less than 300$.


----------



## ab initio

Quote: 





uchihaitachi said:


> That is quite extraordinary. What do you do with bats?


 

 Aerodynamics


----------



## noahbickart

Quote: 





dleblanc343 said:


> All cables were in-store product, and I don't see what you point on being proud of it is all about. The cables I own cost less than 300$.


 
  My point is that when comparing a free product to a $300 product, the ability to distinguish the $300 product from the free only 66.6% of the time is hardly a ringing endorsement, and likely proof of the fact that any differences you "heard" were not a result of purely auditory experience.


----------



## jaddie

Quote: 





noahbickart said:


> My point is that when comparing a free product to a $300 product, the ability to distinguish the $300 product from the free only 66.6% of the time is hardly a ringing endorsement, and likely proof of the fact that any differences you "heard" were not a result of purely auditory experience.


 
  This was clearly an informal test with at least an attempt at making it scientific.  Unfortunately, with only 6 trials there's not enough data for a statistically clear conclusion.  For that, at least 16 trials would be required.  The test was also not double blind, the assistants knew which wire was under test.  
   
  But, and this is important, at least he tried.  It was an attempt to discern differences, and an attempt at a blind test.  That's more than most people do who claim to hear significant differences between cables.  Even though the data is sketchy, and there's room to improve the test methodology, kudos for the attempt.


----------



## bigshot

dleblanc343 said:


> Indeed, but that would take a long time! those 6 tries took about 20 minutes total.




When I was comparing lossy codecs to lossless, I spent a week testing all kinds of music in every codec available. I think my iPod vs CD player test took two days. SACD vs CD took over a week. It's worth the time knowing these things for yourself.


----------



## Greenleaf7

I'm in





bigshot said:


> When I was comparing lossy codecs to lossless, I spent a week testing all kinds of music in every codec available. I think my iPod vs CD player test took two days. SACD vs CD took over a week. It's worth the time knowing these things for yourself.




I'm interested to know the results of your iPod vs CD and SACD vs CD tests. I did a fully sighted 320kbps vs lossless test and honestly I couldn't tell the difference between the two codecs.


----------



## anetode

Quote: 





white lotus said:


> I can't tell if we are all being trolled or not.


 

I can't either.


----------



## bigshot

greenleaf7 said:


> I'm in
> I'm interested to know the results of your iPod vs CD and SACD vs CD tests. I did a fully sighted 320kbps vs lossless test and honestly I couldn't tell the difference between the two codecs.




I determined that above 256 AAC or 320 LAME MP3, there were no differences. The line out from an iPod classic playing a lossless track was indistinguishable from several standalone CD players I had. SACD vs CD is difficult, because usually the redbook layer of a hybrid SACD has different mastering than the SACD layer. I finally found a DSD recorded hybrid that had the same mastering on both layers and they were identical on my system and the system of a professional sound mixer friend.


----------



## nick_charles

Quote: 





bigshot said:


> I determined that above 256 AAC or 320 LAME MP3, there were no differences. The line out from an iPod classic playing a lossless track was indistinguishable from several standalone CD players I had. SACD vs CD is difficult, because usually the redbook layer of a hybrid SACD has different mastering than the SACD layer. I finally found a DSD recorded hybrid that had the same mastering on both layers and they were identical on my system and the system of a professional sound mixer friend.


 
   
   
  How did you do the blinding or were these sighted tests ?


----------



## 00940

Can't believe we're still at it.
   
  Quote: 





bigshot said:


> Can someone please explain to me how binary data can get "rounded corners" like that?
> 
> As I understand it, playback from a buffer guarantees that the data is run through the DAC with correct timing. No jitter. If data is being changed because it's being transmitted through the cable incorrectly, that's data corruption, not jitter. Data corruption is easy to measure... if it exists.


 
   
  Well, that's quite easy and iirc I explained all that years ago on this board. This matters *only *with adaptative receivers btw (pcm2707 and the like), *not *the asynchronous ones. In those last ones, jitter is only dependant on the quality of the local clock (which is in turn dependant on the power supply, the pcb layout and so on, but I disgress).
   
  Roughly: data is transmitted through USB in packets. The edge of these packets are used at the receiving end to create a clock. This clock is used to decide at which time the data will leave the receiver's buffer and also as reference for the digital to analog converter that follows. This is done so because you need to prevent the buffer of running either empty or full (those buffers are made as small as possible for IC's size contraints and budgetary reasons*). So, if the edges of the packets are "rounded" by an imperfect transmission line, the receiver will produce an imperfect clock, affecting the D/A process. 
   
*But *the clock in the computer that determines the "departure" timing of the usb packets in the first place is usually very poor. Add to that that clock recovery is also an analog process which is extremely sensitive to power supply noise** and that the USB 5V is often of poor quality to say the least. This explains why some usb adaptative receivers produce master clocks with jitter in the ns range, especially when powered by USB. Both problems are so massive (and you can only get some measure of control on the second one) that I cannot see how USB cables could result in such additional variations in jitter that it could be audible.
   
  I happily use a USB printer cable for myself and I don't lose sleep over it at night and neither should anyone.
   
   
  * a good write up on this from a designer at TI: http://www.eetimes.com/design/audio-design/4009466/Do-we-use-an-existing-USB-core-How-large-should-the-FIFO-be-The-D-A-Diaries-Part-2
  ** Funny quote of the day about that: an engineer once told me that "digital" is just another name for "the most difficult part of the analog world to deal with".


----------



## bigshot

Quote: 





nick_charles said:


> How did you do the blinding or were these sighted tests ?


 
   
  Sighted. I figured if I can't hear a difference, it doesn't really matter. I test for my own uses.
   
  Clear as mud, 00940!


----------



## 00940

Quote: 





bigshot said:


> Clear as mud, 00940!


 
   
  Well, too bad for you.
   
  Read the stuff by Hitoshi Kondoh on eetimes though (link at the bottom of my previous post), it might clear up things and explain you why buffers aren't magical tools.


----------



## uchihaitachi

Quote: 





ab initio said:


> Aerodynamics


 
  Ah I did thermodynamics!
   
  I can tell the difference between 320kbps and flac of piano recordings with statistical significance. 18 trials and i got it right 16 times. Is there a particular reason why I can do this for the piano. The recording is fairly old with a relatively high noise floor. Arthur Rubinstein 1999.


----------



## bigshot

00940 said:


> Well, too bad for you.
> 
> Read the stuff by Hitoshi Kondoh on eetimes though (link at the bottom of my previous post), it might clear up things and explain you why buffers aren't magical tools. :rolleyes:




Woof! That one is even more obtuse! I'm reminded of when I read Canterbury Tales in the original old English in college. Every other word was one not in common use and had a footnote. It took forever to sludge through. I don't know why they just didn't have us read it in normal language. There's something to be said about presenting information clearly.


----------



## bigshot

uchihaitachi said:


> I can tell the difference between 320kbps and flac of piano recordings with statistical significance. 18 trials and i got it right 16 times. Is there a particular reason why I can do this for the piano. The recording is fairly old with a relatively high noise floor. Arthur Rubinstein 1999.




Frauenhofer or LAME? I found there was a difference between codecs with MP3s. You might not be able to tell with AAC which is even better than both.

Piano music has very strong attacks since it's a percussion instrument. If a track is normalized up to full volume, the peaks might clip a tiny bit after being converted to lossy.


----------



## uchihaitachi

Quote: 





bigshot said:


> Frauenhofer or LAME? I found there was a difference between codecs with MP3s. You might not be able to tell with AAC which is even better than both.
> 
> Piano music has very strong attacks since it's a percussion instrument. If a track is normalized up to full volume, the peaks might clip a tiny bit after being converted to lossy.


 
  I could tell by the peak clipping. That is the verbal description I failed to put into words.


----------



## bigshot

Lowering the volume of the CD rip would probably prevent that and you wouldn't be able to tell any more. I've found that some encoders boost the volume a hair when they convert files. If there is no headroom, the peaks go into clipping. I don't know why they don't fix that.


----------



## uchihaitachi

Quote: 





bigshot said:


> Lowering the volume of the CD rip would probably prevent that and you wouldn't be able to tell any more. I've found that some encoders boost the volume a hair when they convert files. If there is no headroom, the peaks go into clipping. I don't know why they don't fix that.


 
  What do you mean by there is no headroom?


----------



## liamstrain

Quote: 





uchihaitachi said:


> What do you mean by there is no headroom?


 
   
  Levels are already nearly to clipping, so any boost is killing data.


----------



## uchihaitachi

Quote: 





bigshot said:


> Lowering the volume of the CD rip would probably prevent that and you wouldn't be able to tell any more. I've found that some encoders boost the volume a hair when they convert files. If there is no headroom, the peaks go into clipping. I don't know why they don't fix that.


 
  Can you recommend any good converters for mac?


----------



## bigshot

You could use Garage Band for that. It has a nomalize function. I generally knock stuff down to 85% - 90%.


----------



## 00940

Quote: 





bigshot said:


> Woof! That one is even more obtuse! I'm reminded of when I read Canterbury Tales in the original old English in college. Every other word was one not in common use and had a footnote. It took forever to sludge through. I don't know why they just didn't have us read it in normal language. There's something to be said about presenting information clearly.


 
   
  Well, it's the eetimes. Engineer's stuff for engineers. If you think that it is obtuse, try reading the USB audio specs, you're in for a nice headache.
   
  Let's try to put it clearly (and really oversimplify it in the process):
   
  - USB packets leave the computer carrying the data. The speed at which they leave is controlled by a first clock (inside the host computer), let's call it the sending clock.
   
  - They travel along the cable and arrive in the buffer. At one point, the data has to go out towards the digital to analog converter. At what speed ? If it is too slow, the buffer will get full and overflow. If it is too fast, the buffer will get empty and the device will go quiet. So, we need a clock to control the rate at which data exit the buffer, let's call it the exit clock. And this clock must be linked to the sending clock.
   
  - In adaptative USB audio, we are going to use the sending clock to derivate the exit one, because we have no idea of what the sending frequency might be. Sending clocks have slightly different speeds in all computers (even worse: the sending speed can be affected by stuff like cpu usage) so we have to adapt to that fact.*
   
  - But the USB cable has no wire to run the clock on it. So we use the packets themselves to get an idea of the speed of the sending clock.
   
  - It is possible to smooth over the link in between the sending clock and the one you re-create, making your recovered clock a lot better than if you just took the timing of the packets and multiplied/divided it to get your exit clock. This process is based on what is call a PLL. Since your buffer is small (for budgetary reasons among others), the smoothing process must happen quickly and cannot be perfect (how good it is depends on your budget...).
   
  - The exit clock is also the one that decide of the timing at the digital to analog converter's inputs. From its accuracy (or jitter) depends the accuracy of the conversion process.
   
  - If you're still with me, you see that the jitter on the exit clock will depend on:
  *1* the "regularity" of the sending clock: if the packets arrive erratically, the PLL has more work to do and will produce an exit clock with more jitter.
  *2* how sharp the packets' edges are. If they are distorted, the PLL doesn't have a perfect idea of when the packets arrive.
   
  - Problem 1 is huge and has nothing to do with the USB cable. Problem 2 is small in comparaison and could be affected by the USB cable and the design of the USB port on your computer.
   
   
  In conclusion: problems that could be caused by usb cables wrt jitter are small compared to other sources of jitter. Either your usb dac can cope correctly** with a poor usb source and then, a fortiori, it can cope with the small problems due to the usb cable. Or it cannot and then you have bigger problems on hand. In either case, "audiophile" usb cables make no sense.
   
   
  * in asynchronous USB, it's the opposite: the receiver tells the computer how fast it must send the packets. But this requires an extra layer of software drivers.
  ** the definition of coping correctly being open to discussion. A datasheet implementation of the pcm2707 will give you about 2-3ns of jitter iirc. Up to you to see if it's ok.


----------



## liamstrain

So if I can sum up - as it relates to Jitter - regardless of the USB transfer mode, the cable can have only a very small (inaudible) effect (in the worst cases - using older, less reliable modes) to none at all (in most cases) - especially if you are already buying better quality dac's.


----------



## 00940

Quote: 





liamstrain said:


> So if I can sum up - as it relates to Jitter - regardless of the USB transfer mode, the cable can have only a very small (inaudible) effect (in the worst cases - using older, less reliable modes) to none at all (in most cases) - especially if you are already buying better quality dac's.


 
   
  yep, that would be a fair summary.
   
  Well, at least in a direct fashion. A cable that would pick interferences or create grounding problems could indirectly affects the IC (usb receiver, dac, etc.) and cause a rise in jitter through power supply modulation (among other degradations of the whole dac's operation). But not through "rounded edges" which was the initial question.
   
  *edit: if "most cases" means "among the expensive dac people buy here on head-fi". I'd be willing to bet most cheap usb sound devices sold today are still using those "older, less reliable modes".


----------



## bigshot

Are there any computer / DAC combinations that produce audible jitter? If so, I'm guessing it's more a problem with the computer than it is the cable or receiving DAC. What computers are susceptible to this? I know Macs aren't. I've read about testing Macs for jitter and even the worse case scenario of AirPorts and Mac computers still didn't get anywhere near the threshold of audibility. I also know that finding a CD player with audible levels of jitter is pretty doggone difficult. Is jitter only an issue with computers?


----------



## mikeaj

I thought that many adaptive DACs, even those that aren't so expensive, used two-chip solutions (USB receiver and DAC chip separate) or otherwise had an onboard oscillator to provide the "exit" clock.
   
  It's just the relatively cheap stuff, like based on PCM2707 etc. where the data transmissions themselves are handled and used to clock the output? Or not? What I mean to say is that anybody who's concerned about jitter, much less digital cables, probably owns something where the exit clock isn't derived from the USB signaling.


----------



## White Lotus

Can someone please explain to me - in their _own _terms and their _own _opinions:

 What does "Jitter" actually sound like?


----------



## bigshot

That was going to be my next question, Jensy!


----------



## xnor

Crazy amounts: pops and clicks?
  High amounts: like drastically reduced bit depth (if you listen to music and not single test tones)?
   
  But when I say high I don't mean a bit higher than usual but unusual, unrealistically high.


----------



## bigshot

Does jitter even exist in the real world?


----------



## 00940

I don't want to get drawn into another argument about jitter. As far as the topic of this thread is concerned, it looks to me like an issue too small to matter.
   
   
  Quote:


mikeaj said:


> I thought that many adaptive DACs, even those that aren't so expensive, used two-chip solutions (USB receiver and DAC chip separate) or otherwise had an onboard oscillator to provide the "exit" clock.
> 
> It's just the relatively cheap stuff, like based on PCM2707 etc. where the data transmissions themselves are handled and used to clock the output? Or not? What I mean to say is that anybody who's concerned about jitter, much less digital cables, probably owns something where the exit clock isn't derived from the USB signaling.


 
   
  Different issues here (and as I said, I oversimplified things in my previous post, so it's partly my fault):
   
  - One chip or two chips, it doesn't matter. In either case,the audio master clock is provided by the usb receiver. If you stick a third chip in between, such as an ASRC or the like, then it's different. The DAC I built uses 3 chipsets (adaptive usb receiver-asrc-dac) and it's quite a common topology. Many dac will even use 4 chipsets (usb to spdif receiver, spdif receiver, asrc or secondary pll, dac). And of course there's now quite an offer of true asynchronous interfaces (something that wasn't true 3 years back).
   
  - In adaptive DACs, there is indeed an onboard oscillator. But it's not directly clocking the DAC, it's part of a clock generation process (taking place in the usb receiver chipset) which involves slaving the exit clock to the packets' incoming frequency (for the reasons explained above). You've got roughly this: you generate an exit clock (using the onboard oscillator) and then you compare it to the input data flow and finally you adjust the frequency of your exit clock to keep the two clocks related. That gets you a much better clock  than if you use directly the USB packets' sending frequency. But not a perfect one, for various reasons. The article linked above (the "obtuse" one) will give you a better idea about how it works in practice and the compromises involved. Only asynchronous USB DACs are directly and wholly clocked by the onboard oscillator.
   
  - The pcm270* serie is actually quite good and uses such a scheme (the pcm2702 being the oldest is performing a bit worse). Only very cheap chipset such as c-media or the like have a _direct _relation in between the USB packets and the audio clock through a (usually poor) PLL.
   
  In any case, it's awfully difficult to draw wide conclusions. You can mix so many chipsets and topologies. Ask me to comment on a particular DAC and we can make educated guesses.


----------



## Steve Eddy

Quote: 





bigshot said:


> Does jitter even exist in the real world?


 
   
  Yes. It's called caffeine. 
	

	
	
		
		

		
			




   
  se


----------



## mikeaj

Quote: 





00940 said:


> - One chip or two chips, it doesn't matter. In either case,the audio master clock is provided by the usb receiver. If you stick a third chip in between, such as an ASRC or the like, then it's different. The DAC I built uses 3 chipsets (adaptive usb receiver-asrc-dac) and it's quite a common topology. Many dac will even use 4 chipsets (usb to spdif receiver, spdif receiver, asrc or secondary pll, dac). And of course there's now quite an offer of true asynchronous interfaces (something that wasn't true 3 years back).
> 
> - In adaptive DACs, there is indeed an onboard oscillator. But it's not directly clocking the DAC, it's part of a clock generation process (taking place in the usb receiver chipset) which involves slaving the exit clock to the packets' incoming frequency (for the reasons explained above). You've got roughly this: you generate an exit clock (using the onboard oscillator) and then you compare it to the input data flow and finally you adjust the frequency of your exit clock to keep the two clocks related. That gets you a much better clock  than if you use directly the USB packets' sending frequency. But not a perfect one, for various reasons. The article linked above (the "obtuse" one) will give you a better idea about how it works in practice and the compromises involved. Only asynchronous USB DACs are directly and wholly clocked by the onboard oscillator.
> 
> - The pcm270* serie is actually quite good and uses such a scheme (the pcm2702 being the oldest is performing a bit worse). Only very cheap chipset such as c-media or the like have a _direct _relation in between the USB packets and the audio clock through a (usually poor) PLL.


 
   
  Thanks for the correction. I'll check out the links whenever I find the time.
   
  I get the feeling like some of these implementation details with respect to synchronization, PLLs, and timing should have been obvious enough if I'd just thought through the process carefully and what was required, even without reading any of the docs. For example, I was thinking that with a large enough buffer, you could just use the oscillator to directly clock the output and ignore the input clock (aside from PLL and whatever necessary on the receiving side to get all the data). But it'd definitely be a problem if one clock averaged a different frequency than the other over the long run—you'd run out of data or have too much and need to drop something—which is something I didn't think about earlier.
   
  Anyway, as for the cable itself generally having an undue influence on the process...


----------



## bigshot

I don't think it's at all productive to talk about what causes jitter and how it works in great technical detail if you don't put that into real world perspective... Is it something that someone is likely to have happening in their own equipment? If so, is it at all audible?
   
  Every time I get drawn down the jitter rabbit hole, it's always the same... reams and reams of technical double speak and then after my brain hurts from trying to absorb it, then the person says... "But of course it really isn't an issue because it's inaudible."
   
  If that's the case, we should just cut to the chase and spare everyone the technical mumbo jumbo.


----------



## mikeaj

PLLs, phase tracking, etc. are ostensibly on the periphery of what's supposed to be my expertise. Consider it partly professional interest. Also, it's bad form to be knowingly perpetuating technical errors.
   
  As for improving sound quality, I doubt it. Regardless of even what the reality is, that discussion's pretty much going nowhere unless somebody can cite a decent listening test that confirms some level of audibility different than what's been established, and I think we already got to that point somewhere in the last 50 pages... probably multiple times.


----------



## 00940

Quote: 





bigshot said:


> Is it something that someone is likely to have happening in their own equipment?


 
   
  You need to qualify your questions... what is happening ? Measurable jitter in between 500ps and 3-4ns ? Of course. It's a matter of engineering.
   
  Quote: 





> If so, is it at all audible?


 
   
  Probably not. It's a matter of psycho-acoustics.
   
  Quote: 





> Every time I get drawn down the jitter rabbit hole, it's always the same... reams and reams of technical double speak and then after my brain hurts from trying to absorb it, then the person says... "But of course it really isn't an issue because it's inaudible."
> 
> If that's the case, we should just cut to the chase and spare everyone the technical mumbo jumbo.


 
   
  The difference is that the person who concludes by saying it's inaudible has grounds to say so (isn't it the science forum, where opinions must be substantiated ?). If you want to cut the chase, two tips:
   
  1/ ask the technical minded persons what levels of jitter are actually involved and then ask for proof of audibility (in the realm of psycho-acoustics).
  2/ avoid getting drawn in the technical aspect of it, There's no "double speak". It's just complicated. Best way to proceed is to avoid open (and false) statements such as "digital is perfect, all that matters are 0 and 1". This kind of things just begs to be corrected by a lot of technical mumbo jumbo.


----------



## bigshot

Who cares if jitter exists if it isn't audible? Thresholds of perception are a part of science too. Speaking about something in theory without putting all those numbers and specs into perspective is deceptive. Human specs / electronic specs... they are related.

We're all here to get stereo systems that sound good to us, right? We're trying to help people, not just listen to ourselves speak.

Obfuscation by inundating the listener in technical minutia is what snake oil salesmen do. Sound Science people shouldn't add to that confusion. Our purpose should be to explain and put into context.


----------



## nick_charles

Quote: 





00940 said:


> 1/ ask the technical minded persons what levels of jitter are actually involved and then ask for proof of audibility (in the realm of psycho-acoustics).


 
   
  From much searching including the AES library to date there have been 3 research papers which have more or less seriously attempted to* empirically *determine the limits of audibility. One is a 1970s BBC paper, one is from two dudes at Dolby labs (Benjamin and Gannon)  (1998) and the last is from NHK (Japanese Public Broadcaster)  in 2005. The types and levels differed, what all three implicitly agreed on was that achieving an audible level required pathologically bad equipment. The Dolby labs paper (the most conservative) put audibility for a single tone at about 10ns signal-correlated jitter rising to over 300ns with some musical samples with a minimum of 30ns for musical samples
   
    


> Sine wave thresholds were measured using the UDTR technique. The threshold for sine waves is lowest for the case of 20 kHz FS reproduction where the mean threshold was found to be 10 ns tins of sinusoidal jitter at frequencies at 17 kHz. For 4 kHz sine wave full-scale reproduction, the threshold is raised due to the decrease in the amount of distortion due to jitter, and to the masking of the distortion components in the frequency range between 1 kHz and 7 kHz where the ear is most sensitive. For 4 kHz sine waves the threshold was found to be 100 ns rms....
> 
> Extensive listening tests using several subjects were conducted to determine the amount of jitter that caused a just Noticeable Difference (JND) on these particular program examples. It was found that training enabled the subjects to hear the distortion caused by jitter at a lower level than at initial exposure to the phenomenon. The threshold of detection ranged from about 30 ns rms to 300 ns rms of sinusoidal jitter for critical source material.
> 
> The influence of jitter in causing audible distortion was found to be less than anticipated by the authors, and less than that predicted by both the technical and consumer audio press. Jitter induced by the digital audio interface was not found to be an audible problem for any of the program material auditioned.


 
   
   
  I've petitioned many of those that might be called jitter-worriers to provide good counter evidence for the lower thresholds they claim are audible and to date have not had one credible piece of evidence, thus I no longer consider jitter to be an issue.


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## 00940

@Bigshot: I very much doubt this particular thread is really helping anyone... But it's the cynical in me speaking.
   
  A few pages back, you wanted explanations. Need I remind you ?
   
  Quote: 





> Can someone please explain to me how binary data can get "rounded corners" like that?
> 
> As I understand it, playback from a buffer guarantees that the data is run through the DAC with correct timing. No jitter. If data is being changed because it's being transmitted through the cable incorrectly, that's data corruption, not jitter. Data corruption is easy to measure... if it exists.


 
   
  Sorry, but you should make up your mind about what you want. If you don't understand the technical aspects and don't want to spend time to learn, that's all fine. But don't comment on them. Because you are the one confusing things by doing so.
   
  In other terms, what's the most confusing thing to tell to someone reading jitter oriented marketing litterature: "there's no jitter; here are plenty of (wrong) reasons why" or "there might be jitter indeed, we know where it comes from but the levels involved here are below audibility ?"
   
   
  @nick_charles: that's all fine with me (and we've discussed those papers a lot already in the past). Let's keep 10ns to be on the safe side and have a nice easy value to remember. As said in my post above, half-decent adaptive receivers give at worst about 3ns of jitter (for pcm2702 and pcm2902, pcm2707 are in between 500ps and 1ns) and we agree that it's probably not audible.


----------



## 00940

@Bigshot: I very much doubt this particular thread is really helping anyone... But it's the cynical in me speaking.
   
  A few pages back, you wanted explanations. Need I remind you ?
   
  Quote: 





> Can someone please explain to me how binary data can get "rounded corners" like that?
> 
> As I understand it, playback from a buffer guarantees that the data is run through the DAC with correct timing. No jitter. If data is being changed because it's being transmitted through the cable incorrectly, that's data corruption, not jitter. Data corruption is easy to measure... if it exists.


 
   
  Sorry, but you should make up your mind about what you want. If you don't understand the technical aspects and don't want to spend time to learn, that's all fine. But don't comment on them. Because you are the one confusing things by doing so.
   
  In other terms, what's the most confusing thing to tell to someone reading jitter oriented marketing litterature: "there's no jitter; here are plenty of (wrong) reasons why" or "there might be jitter indeed, we know where it comes from but the levels involved here are below audibility ?"
   
   
  @nick_charles: that's all fine with me (and we've discussed those papers a lot already in the past). Let's keep 10ns to be on the safe side and have a nice easy value to remember. As said in my post above, half-decent adaptive receivers give at worst about 3ns of jitter (for pcm2702 and pcm2902, pcm2707 are in between 500ps and 1ns) and we agree that it's probably not audible.


----------



## bigshot

I would think the simplest and most accurate answer to the question would be, "It can't be heard so it really isn't worth worrying about."
   
  Perhaps people are here for reasons different than I am. I'm looking for the Sound Science forum to make sense of the technical aspects of sound reproduction for the purpose of improving the way my music sounds when I listen to my stereo system. This thread just confused me and led me astray into thoughts of angels dancing on heads of pins.
   
  I know a little bit about how digital audio works. But I've never owned an external DAC, only AV receivers and standalone players. I did the research into jitter as it applies to those particular applications and determined it was well below the audible level. No need to think any further about it. Bigger fish to fry. I come to this thread and people are talking about "massive" problems and a whole bunch of technical cut and paste and I don't think it takes a huge leap to assume that if people are talking about it with such vehemence, it must be a serious problem.
   
  It's actually my mistake. I should have just ignored all that stuff and gone with my gut and posted the simplest and most accurate answer. Honestly, every time I look into jitter it just makes me mad that anyone is worrying about it at all. Jitter is a hoodoo.


----------



## Rawrbington

Not trying to derail this discussion, as I love it.  But I have a question about my current USB cable and my USB dac.
  I have an old fubar ii usb dac doing its duty in my bedroom rig.  The problem is, I get occaisionaly, but sometimes fairly frequent dropping out and what sounds like skipping.  Sometimes it won't happen for 30 minutes, other times it happens sever times in a 2 minutes period.
  could this be my cable?  Im using a random printer cable with the ferrite core thing.  It's of unknown age(could be 10+ years old).
  Now,  I'm on one clear side of this debate, BUT in this situation, could it be my cable, or (most probably) my usb ports/mobo?


----------



## liamstrain

Much more likely to be computer issues. Shared resources, or other. Many people have noticed issues with their graphics card stealing memory and causing usb audio issues (especially when re-painting the screen during web browsing, for instance). Check out the computer audio threads for some specific troubleshooting suggestions. 
   
  Unless the cable is quite long (over 3m) it is the least likely culprit IMO.


----------



## White Lotus

This should fix it.

http://www.musicdirect.com/p-60767-crystal-cable-crystal-usb-diamond-cable.aspx

Don't actually do it, I'm being sarcastic
   
  But really though, does wiggling/fiddling with the cable fix/effect the problem? Does it do it across all software platforms, or just one application?


----------



## dvw

Quote: 





rawrbington said:


> Not trying to derail this discussion, as I love it.  But I have a question about my current USB cable and my USB dac.
> I have an old fubar ii usb dac doing its duty in my bedroom rig.  The problem is, I get occaisionaly, but sometimes fairly frequent dropping out and what sounds like skipping.  Sometimes it won't happen for 30 minutes, other times it happens sever times in a 2 minutes period.
> could this be my cable?  Im using a random printer cable with the ferrite core thing.  It's of unknown age(could be 10+ years old).
> Now,  I'm on one clear side of this debate, BUT in this situation, could it be my cable, or (most probably) my usb ports/mobo?


 
  I had a similar problem. It was a driver issue. Install new drivers and everything's running.


----------



## Greenleaf7

Quote: 





white lotus said:


> http://www.musicdirect.com/p-60767-crystal-cable-crystal-usb-diamond-cable.aspx


 
  I'm pretty sure this cable will 'open up the soundstage' and remove the 'veil'.
   
  Don't forget to choose one of these http://www.musicdirect.com/c-618-powerline-conditioners.aspx
  Remember, your audio rig is never complete without a high end power conditioner.
   
  You'll also need an audiophile grade wall plug to get the best out of your system.
http://www.musicdirect.com/p-7398-oyaide-carbon-fiber-wall-plate-without-outlet.aspx
   
  And to top it off, you'll need to demagnatize your equipment from time to time.
http://www.furutech.com/2013/02/02/1792/


----------



## xnor

@rawrbington: check your PC's DPC latency with something like LatencyMon or DPC Latency Checker.
   
  If that is fine try other USB ports.


----------



## Rawrbington

im pretty sure you guys are right.  i'll check it out and see what happens.  its an older system,  core 2 quad built in 2008.  and it does seem more prevalent when im doing other things (multitasking). 
  thanks for the info


----------



## radiofrog

Quote: 





greenleaf7 said:


> And to top it off, you'll need to demagnatize your equipment from time to time.
> http://www.furutech.com/2013/02/02/1792/


 
   
  Awww... no price on this one.  I have GOT to have one of these!  My music is sounding so magnetized right now.


----------



## uchihaitachi

Quote: 





radiofrog said:


> Awww... no price on this one.  I have GOT to have one of these!  My music is sounding so magnetized right now.


 
 "... demagnetizing an LP definitively removed a high-frequency glaze or glare and seemed to enrich the midband... Demagnetizing LPs works. And do not try one of these devices unless you're prepared to buy it."[size=10pt]
 --Michael Fremer, Stereophile[/size]

  I don't know whether to laugh or cry.


----------



## Greenleaf7

Quote: 





radiofrog said:


> Awww... no price on this one.  I have GOT to have one of these!  My music is sounding so magnetized right now.


 
  Don't stop there, it's also essential to keep your equipment static and dust free.
   
http://www.furutech.com/2013/02/02/1794/


----------



## Steve Eddy

Quote: 





uchihaitachi said:


> "... demagnetizing an LP definitively removed a high-frequency glaze or glare and seemed to enrich the midband... Demagnetizing LPs works. And do not try one of these devices unless you're prepared to buy it."[size=10pt]
> --Michael Fremer, Stereophile[/size]
> 
> I don't know whether to laugh or cry.


 
   
  Cry. Definitely, cry.
   
  Fremer's the same reviewer who reviewed some analog cables that used fiber optics, with electro-optical converters on each end first converting from electrical to optical for transmission, and then from optical to electrical at the receiving end.
   
  Of these he wrote that they were "the most significant technological breakthrough I have experienced in my career as an audio reviewer. It is immediately superior in every way."
   
  Now, normally Stereophile doesn't do any measurements on cables, because other than simple resistance, inductance and capacitance, there's really nothing to measure. But because these cables used active devices in them, John did do a suite of measurements on these particular cables. The measurements were so bad, he wrote of them "If this were a review of a conventional product, I would dismiss it as being broken."
   
  Ironically, Fremer used to be a comedian.
   
  se


----------



## Steve Eddy

Quote: 





greenleaf7 said:


> Don't stop there, it's also essential to keep your equipment static and dust free.
> 
> http://www.furutech.com/2013/02/02/1794/


 
   
  I love that oxymoron. The name is "Destat II," but they call it a "static charger."
   
  Having said that though, I will say I don't think there's anything wrong with ionizers (though I'm not sure exactly what the Destat does), especially if you have an analog setup. Properly implemented, they do work.
   
  se


----------



## uchihaitachi

Quote: 





steve eddy said:


> I love that oxymoron. The name is "Destat II," but they call it a "static charger."
> 
> Having said that though, I will say I don't think there's anything wrong with ionizers (though I'm not sure exactly what the Destat does), especially if you have an analog setup. Properly implemented, they do work.
> 
> se


 
  So what exactly are the requirements to be a reviewer at Stereophile?


----------



## xnor

The crazier the better!


----------



## Steve Eddy

Quote: 





uchihaitachi said:


> So what exactly are the requirements to be a reviewer at Stereophile?


 
   
  I'm afraid you'd have to ask John. He's the editor.
   
  se


----------



## White Lotus

Greenleaf, I had quite the chuckle at your post, thank you. Lets not stop there, we might as well look at the improvements that your TV could use, as well.
   
  After all, we want your experience to be a premium one. 

http://www.amazon.com/AudioQuest-Coffee-12m-Braided-HDMI/dp/B003CT5KMO/ref=sr_1_9?s=electronics&ie=UTF8&qid=1345758453&sr=1-9


----------



## bigshot

I was skeptical, but when they said that this HDMI cable could serve me breakfast in bed, I was SOLD!


----------



## White Lotus

> Frankly, I'm a little angry at the sarcastic reviews posted for this HDMI cable. Many people come to Amazon in order to see HONEST opinions about the products they are looking to purchase. It is clear that some of the reviewers have not purchased this item, or are making up stories. I really don't believe that somebody quit their job just to be a delivery person in order to make sure the cable was delivered properly.
> 
> Also, several people seem to be making fun of the length of the cable. Yes, 12 meters may seem like an odd length to Americans, but to many people in the world, that may be a very useful length. It just depends upon your culture.
> 
> ...


----------



## Greenleaf7

Quote: 





white lotus said:


> Greenleaf, I had quite the chuckle at your post, thank you. Lets not stop there, we might as well look at the improvements that your TV could use, as well.
> 
> After all, we want your experience to be a premium one.
> 
> http://www.amazon.com/AudioQuest-Coffee-12m-Braided-HDMI/dp/B003CT5KMO/ref=sr_1_9?s=electronics&ie=UTF8&qid=1345758453&sr=1-9


 
  Thanks for the suggestion, I immediately purchased one to replace my under performing HDMI cable. The quest for audio/ video perfection is far from complete without a audiophile grade power cord such as this.
   
http://www.amazon.com/AudioQuest-NRG-WEL-Signature-Power/dp/B0055OM9WS/ref=sr_1_5?s=electronics&ie=UTF8&qid=1370506968&sr=1-5&keywords=audioquest+diamond
   
  More info here:
http://www.audioquest.com/hdmi/diamond


----------



## bigshot

I'll take Birgit Nilsson, Elisabeth Schwartzkopf and Kirstin Flagstad, thankyouverymuch.


----------



## liamstrain

robertsong - I notice you don't quote any of the posts from the engineers who have posted since.


----------



## Mambosenior

robertsong said:


> ...a farting, belching, trailer-trash whore.




I've heard good Traviatas from a few of these.


----------



## 00940

Quote: 





bigshot said:


> I'll take Birgit Nilsson, Elisabeth Schwartzkopf and Kirstin Flagstad, thankyouverymuch.


 
   
  Let's be fair. Renee Fleming has some very good recordings. I particularly like the Cosi fan tutte by Solti, with Fleming and Von Otter as leads.
   
   
  I shouldn't post this, really I shouldn't: http://www.diyaudio.com/forums/everything-else/236248-fancy-interconnects-how-about-potato-even-mud.html


----------



## White Lotus

I am close to 100% sure that Robertsong is trolling us.


----------



## liamstrain

Poe's law.


----------

