Head-Fi.org › Forums › Equipment Forums › Sound Science › My cable test enterprise
New Posts  All Forums:Forum Nav:

My cable test enterprise - Page 24

post #346 of 438
Quote:
Originally Posted by kwkarth View Post

Yes, it was moved and I was the one that moved it.

Quote:
Originally Posted by kwkarth View Post

I just happened to notice that it was not where it belonged, so I moved it.  


Hey KW, why don't you think it belonged in the regular cable thread?

 

USG

 


 

post #347 of 438
Quote:
Originally Posted by upstateguy View Post

Hey KW, why don't you think it belonged in the regular cable thread?

 

USG

Because DBT testing is being discussed along with the outright validity or not of cable differences being debated.  Such stuff belongs in SS forum.
 

post #348 of 438
Quote:
Originally Posted by kwkarth View Post



Because DBT testing is being discussed along with the outright validity or not of cable differences being debated.  Such stuff belongs in SS forum.
 


Because DBT and these cable measurements are best marginalised in the Sound Science part of the forum. That way the pro cable side can continue to ignore the science and make spurious untested claims instead. Could we have a section called 'Bad Science' to marginalise all the 'night and day', 'golden ears', 'decent hifi kit, 'psyedoscience'' reasons as to why cables do make a difference?

post #349 of 438

 

Originally Posted by nick_charles View Post

 

A plastic optical fiber cable connecting the optical out on a Lenovo Y710 notebook to an Entech 203.2 which uses a CS8412 input receiver. Conversion is performed by a CS4329 20-bit delta-sigma DAC, and there is a Burr-Brown OPA2134 op-amp 

 

I don't mean to sound pedantic, but you're collecting the bottlenecks:
-POF Toslink, with its very poor bandwidth that smears the HF...the clock recovery on the receiver ends suffers.
-OPA2134, which is a terrible sounding jelly bean dual opamp
-CS8412, which is a very old(1998!) and high jitter S/PDIF receiver
-Toslink output from your laptop, prolly using a Realtek chip or so?
-Your DAC that most likely runs from a SMPS wallwart.
-on your link it says that your DAC has >900ps jitter!

-your entry level dynamic headphones

 

This rig is hopeless to roll cables/opamps, I fully agree that everything would sound the exact same on this set up. If you wanna get to the bottom of all this, I'd try something based on:

-WM8804, the top S/PDIF receiver in town

-any recent single opamps from TI, such as OPA1641/OPA827 and so

-a short coax

-a DAC running off a low ripple linear regulated PSU

-a pair of Fostex T50RP(cheap and analytical to death)

-a low jitter USB transport

 

Then, nocebo aside, you will most likely be able to hear differences between cables.

post #350 of 438

What I find utterly sarcastic w/ coax cables is that the requirements for composite video and S/PDIF are perfectly identical...but composite is the worst kind of video connection you can get, so the very same wire costs significantly less. I've just bought a $3 coax cable(24K gold plating, killer shielding, high purity copper) from a major manufacturer, and it might very well be the best coax cable I've heard so far. It sure as hell kills the Belden 1794A/Canare combo. As soon as you buy cables specifically  meant for audio, markups go up through the roof for some reason.

post #351 of 438
Thread Starter 
Quote:
Originally Posted by leeperry View Post

 

 

I don't mean to sound pedantic, but you're collecting the bottlenecks:
-POF Toslink, with its very poor bandwidth that smears the HF...the clock recovery on the receiver ends suffers.

 

Can you back this assertion up with some controlled listening tests and using what as a comparator, citations would be very useful here, audiophile anecdotes are less so since we have been relegated to the science ghetto

 

 

-OPA2134, which is a terrible sounding jelly bean dual opamp

 

Can you back this assertion up with some controlled listening tests and using what as a comparator, citations would be very useful here, audiophile anecdotes are less so since we have been relegated to the science ghetto

 


-CS8412, which is a very old(1998!) and high jitter S/PDIF receiver

 

Look into the actual published research on jitter audibility and you will see that jitter below 10ns is not verified as an audible problem by any controlled tests


-Toslink output from your laptop, prolly using a Realtek chip or so?

 

Realtek - so what ?


-Your DAC that most likely runs from a SMPS wallwart.

 

???? - it has its own dedicated and utterly non-interchangeable AC (yes AC) PSU, but again you will have to show me evidence that this matters and not audiophile dogma


-on your link it says that your DAC has >900ps jitter!

 

Only on Coax not on Toslink where it is < 160ps - but see above for jitter audibility notes as 900ps is not known to be audible

 

 

-your entry level dynamic headphones

 

ah the insults continue - on what exact parameters do these headphones constitute a serious bottleneck in terms of distinguishing between stimulae, I hope the concept of cost is not one of them.

 

 

This rig is hopeless to roll cables/opamps, I fully agree that everything would sound the exact same on this set up. If you wanna get to the bottom of all this, I'd try something based on:

-WM8804, the top S/PDIF receiver in town

-any recent single opamps from TI, such as OPA1641/OPA827 and so

-a short coax

-a DAC running off a low ripple linear regulated PSU

-a pair of Fostex T50RP(cheap and analytical to death)

-a low jitter USB transport

 

Then, nocebo aside, you will most likely be able to hear differences between cables.

 

 

If you want to prove your case why don't you simply use your setup and do your own properly proctored double blind tests and report back.

 

Get your own high end recording device to make samples or get an accomplice to help you run proper DBTS ( n>= 15) and then see if you can tell the difference between different (normal) cables, but seriously, first measure them and see just how similar normal cables really are, you may be surprised, till then you are just echoing well-worn dogma and not adding any actual evidence to the discourse.

 

Here in the back of the bus we are allowed to ask for evidence beyond I hear a difference when I know what I am listening to.



 

post #352 of 438

Wait, since when are HD 580s "entry level" headphones?!?  In 1994 they were, essentially, the best dynamic headphones on the planet!  Even today they're in the upper echelon of headphone performance...

 

I think you're a bit out of touch with the truth...

 

Jitter on the order of 1 ns (1000 ps) is utterly and entirely irrelevant, despite what you may believe.  Show me scientific evidence saying otherwise and I might change my mind.  Until then, read this:

http://www.jstage.jst.go.jp/article/ast/26/1/50/_pdf

 

Jitter was found to be not audible until it was on the order of several hundred ns...

 

The staggering stubbornness of some people to believe something in the face of all evidence to the contrary astounds me.  However, I would like to see more rigorous tests like this - if I had the means I'd try it myself...

post #353 of 438
Thread Starter 



 

Quote:
Originally Posted by kwkarth View Post



Because DBT testing is being discussed along with the outright validity or not of cable differences being debated.  Such stuff belongs in SS forum.
 



Are you saying that the suggestion that a subjective experience of differences may be illusory or the result of poor comparison conditions and/or well-known cognitive biases is unacceptable in the other place ?

 

I need to get this straight so I do not stray again.

post #354 of 438
Quote:
Originally Posted by nick_charles View Post


Here in the back of the bus we are allowed to ask for evidence beyond I hear a difference when I know what I am listening to.

 


lol, I just had to snag that for my sig!  Excellent post.

post #355 of 438

you know, Nick, you're a non-believer and you refuse to try real world experiments...whatever I'll tell you you'll always call me on it, and you know that ;)

 

you refuse to try glass toslink, a low jitter transport or analytical headphones...that can't be helped.

 

1) the pof/glass toslink difference is very real, way beyond the placebo gods...have you ever compared them? it's been thoroughly discussed on many forums: http://www.audioasylum.com/cgi/t.mpl?f=cables&m=60710

 

"the maximum bandwidth to the S/PDIF transmission is 3.3 Mhz, but in order to form a perfect square wave there are harmonics out to 30 Mhz."

 

http://www.google.com/search?q=plastic+toslink+bandwidth+6+mhz&hl=en&source=hp&aq=f&aqi=&aql=&oq=

 

You seem to refuse to order stuff and send it back for a refund later on, but if you ever change your mind give a shot at the Dayton glass toslink cables....they sound FAR better than POF ever will, for all the reasons explained in the aforementioned link. Of course, coax has the edge over any kind of Toslink, because the light conversions use cheapo LED's as light sources, and that's a poor solution by design.

 

2) Dual opamps are just terrible, they're flawed by design..even TI say so: http://focus.ti.com/docs/prod/folders/print/opa1612.html

 

"The dual version features completely independent circuitry for lowest crosstalk and freedom from interactions between channels"

 

Any experienced opamp roller will tell you that, or better....get something w/ rollable opamps and try it? you know, real world experience.

 

3) Here's a paper about jitter on the CS chips, it's rather interesting how high the jitter is on CS8416 in legacy mode: http://www.cirrus.com/en/pubs/appNote/AN339REV1.pdf

 

and AFAIK, CS8412 is even more ancient than CS8416.

 

4) Breaking news, you're listening to the PSU...do I really have to prove my point about this?

 

5) Well yeah, Orthos are another dimension over grossly overpriced and obsolete dynamic headphones...some dare saying that a modded T50RP kills much more expensive dynamic headphones. All I know is that it makes the cd3k sounds like ibuds....it costs $74 BTW. You simply can't beat technological advance...the coil/diaphragm technology is +80 yo, these ppl are basically selling pimped DT48's w/ stellar markups.

 

Oh yah, I forgot, you guys at the back of the bus are of the dubious kind...here you go, check out the last page of this PDF: http://www.fostexinternational.com/docs/downloads/pdfs/RP_Headphones_Brochure.pdf

 

They used to have a webpage about it as well, but it's a 404 now...I've archived it here in a ZIP file(you can zoom on the pictures): http://www.mediafire.com/?27138810cbs5cye

 

6) I don't have any point to make, just that saying that all cables sound the same doesn't match MANY ppl's *real world* experience...using lofi gear will never allow you to hear any difference. But keep on thinking that all perceived differences are due to placebo, and that the ppl who hear them are stray sheeps that require guidance badly if you like [:icon12]

post #356 of 438
Thread Starter 
Quote:
Originally Posted by leeperry View Post

you know, Nick, you're a non-believer and you refuse to try real world experiments...whatever I'll tell you you'll always call me on it, and you know that ;)

 

I bought many different cables and tried them out , more importantly I measured them and they despite price differences of a factor of over 150x they were all very similar

 

 

you refuse to try glass toslink, a low jitter transport or analytical headphones...that can't be helped.

 

 

1) the pof/glass toslink difference is very real, way beyond the placebo gods...have you ever compared them? it's been thoroughly discussed on many forums: http://www.audioasylum.com/cgi/t.mpl?f=cables&m=60710

 

"the maximum bandwidth to the S/PDIF transmission is 3.3 Mhz, but in order to form a perfect square wave there are harmonics out to 30 Mhz."

 

http://www.google.com/search?q=plastic+toslink+bandwidth+6+mhz&hl=en&source=hp&aq=f&aqi=&aql=&oq=

 

But has the difference been established as audible by any proper tests ?

 

 

You seem to refuse to order stuff and send it back for a refund later on, but if you ever change your mind give a shot at the Dayton glass toslink cables....they sound FAR better than POF ever will, for all the reasons explained in the aforementioned link. Of course, coax has the edge over any kind of Toslink, because the light conversions use cheapo LED's as light sources, and that's a poor solution by design.

 

 

But has the difference been established as audible by any proper tests ?

 

2) Dual opamps are just terrible, they're flawed by design..even TI say so: http://focus.ti.com/docs/prod/folders/print/opa1612.html

 

"The dual version features completely independent circuitry for lowest crosstalk and freedom from interactions between channels"

 

Any experienced opamp roller will tell you that, or better....get something w/ rollable opamps and try it? you know, real world experience.

 

And they have confirmed this with controlled listening tests ?

 

 

3) Here's a paper about jitter on the CS chips, it's rather interesting how high the jitter is on CS8416 in legacy mode: http://www.cirrus.com/en/pubs/appNote/AN339REV1.pdf

 

and AFAIK, CS8412 is even more ancient than CS8416.

 

 

But I've already both pointed to actual measurements and how little jitter matters !

 

4) Breaking news, you're listening to the PSU...do I really have to prove my point about this?

 

But has the difference been established as audible by any proper tests ?

 

5) Well yeah, Orthos are another dimension over grossly overpriced and obsolete dynamic headphones...some dare saying that a modded T50RP kills much more expensive dynamic headphones. All I know is that it makes the cd3k sounds like ibuds....it costs $74 BTW. You simply can't beat technological advance...the coil/diaphragm technology is +80 yo, these ppl are basically selling pimped DT48's w/ stellar markups.

 

Possibly interesting but sadly everywhere shows these as back-ordered or discontinued !

 

 

Oh yah, I forgot, you guys at the back of the bus are of the dubious kind...here you go, check out the last page of this PDF: http://www.fostexinternational.com/docs/downloads/pdfs/RP_Headphones_Brochure.pdf

 

They used to have a webpage about it as well, but it's a 404 now...I've archived it here in a ZIP file(you can zoom on the pictures): http://www.mediafire.com/?27138810cbs5cye

 

6) I don't have any point to make, just that saying that all cables sound the same doesn't match MANY ppl's *real world* experience...

 

But has the difference been established as audible by any proper tests ? I can say I can fly but I cannot prove it, I might even sincerely believe I can fly but I am unable to provide evidence for this !

 

 



 

post #357 of 438
Quote:
Originally Posted by Prog Rock Man View Post

Because DBT and these cable measurements are best marginalised in the Sound Science part of the forum. That way the pro cable side can continue to ignore the science and make spurious untested claims instead. Could we have a section called 'Bad Science' to marginalise all the 'night and day', 'golden ears', 'decent hifi kit, 'psyedoscience'' reasons as to why cables do make a difference?

This is it. tongue_smile.gif
 

post #358 of 438
Thread Starter 
Quote:
Originally Posted by kwkarth View Post



This is it. tongue_smile.gif
 


Freudian slip or obvious evidence of bias amongst the mod/admin hierarchy ?
 

post #359 of 438
Quote:
Originally Posted by nick_charles View Post

Are you saying that the suggestion that a subjective experience of differences may be illusory or the result of poor comparison conditions and/or well-known cognitive biases is unacceptable in the other place ?

 

I need to get this straight so I do not stray again.

No, I simply said that such circular arguments largely participated in by people who really don't know what they're talking about belongs here rather than in a forum dedicated to purely subjective impressions.  This is the appropriate place for all of the pseudo science discussions/arguments.  We have lots of people who know they don't have scientific explanations for what they think they perceive, and they're happy to discuss their perceptions with that understanding.  Then we have people who largely are no more knowledgeable re the science, but cloak their subjective impressions in the guise of science.  This is the place for that sort of "discussion."
 

post #360 of 438
Quote:
Originally Posted by nick_charles View Post

Freudian slip or obvious evidence of bias amongst the mod/admin hierarchy ?

This is the right sandbox for such discussions.  It wasn't my idea, someone smarter than me came up with the idea.
In other words Nick, this is the place for people who are here to argue, rather than here to learn.  There are exceptions that rule of thumb, but that, is the way it largely is.

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Sound Science
Head-Fi.org › Forums › Equipment Forums › Sound Science › My cable test enterprise