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My cable test enterprise - Page 27

post #391 of 438
Thread Starter 



 

Quote:
Originally Posted by BlackbeardBen View Post



 

Show me studies or tests of any sort (not sighted, of course) that show that such jitter at such levels you're talking about is in fact audible, and I'll gladly review them.  Show me.  I want to see evidence for the audibility of jitter at levels of under one nanosecond.

 

Quote:
Originally Posted by leeperry View Post

 


Get a Firestone Bravo from any reseller, you got 1 or 2 weeks to get a refund...try to reclock Realtek POF toslink(worst case scenario, use a long cable too) to a short coax(4/5ft), and you'll hear what it's all about. That's the only hard clue I can provide...The sound will be clearer and tighter, less distorted and less colored...more punchy too.

 

I would lend you my Bravo but I reside overseas, and I kinda use it everyday ^^

 

That's the only PNP WM8804 reclocker on the market AFAIK, otherwise there's this board(I've seen it selling for $50 second hand here on head-fi): http://www.twistedpearaudio.com/digital/wm8804.aspx

 

I don't see how anyone could say that WM8804's effect on jitter is inaudible. Other owners in the Bravo thread have confirmed that going toslink>coax was quite a blast. S/PDIF jitter is nasty because it compromises the clock extraction..as quoted above, it "leaves the recovered clock contaminated with signal correlated jitter artefacts".


BB,  seriously do not get drawn in this, you'll buy the device, not hear any difference and when you report this LP will simply say that your kit is just not good enough or your hearing is defective/untrained !
 

If you try to get round this by recording samples from the analog out of your DAC (with and without the wonder device) to use in DBT or mathematical comparisons the recording device will not be good enough either. The massive (night and day) difference will somehow fail to survive the digitization process.

 

@Lee if I bought one of those Bravo devices and compared the analog out of my 24/96 DAC in four different modes - USB mode, Toslink mode,  USB---Bravo-----Coax mode and USB---Bravo-----toslink mode and performed careful recordings would you accept the FR differences measured from 20hz - 20hz as evidence for the impact (or not) of jitter  ?

post #392 of 438
Quote:
Originally Posted by leeperry View Post

 


Get a Firestone Bravo from any reseller, you got 1 or 2 weeks to get a refund...try to reclock Realtek POF toslink(worst case scenario, use a long cable too) to a short coax(4/5ft), and you'll hear what it's all about. That's the only hard clue I can provide...The sound will be clearer and tighter, less distorted and less colored...more punchy too.

 

I would lend you my Bravo but I reside overseas, and I kinda use it everyday ^^

 

That's the only PNP WM8804 reclocker on the market AFAIK, otherwise there's this board(I've seen it selling for $50 second hand here on head-fi): http://www.twistedpearaudio.com/digital/wm8804.aspx

 

I don't see how anyone could say that WM8804's effect on jitter is inaudible. Other owners in the Bravo thread have confirmed that going toslink>coax was quite a blast. S/PDIF jitter is nasty because it compromises the clock extraction..as quoted above, it "leaves the recovered clock contaminated with signal correlated jitter artefacts".

 

 

Again, I'm looking for empirical evidence, not testimonials...


While testing myself is something I would try if I had unlimited time and money - I don't have either of those.  I don't have my sole optical source (which I just use the integrated DAC with anyway) within three thousand miles of me (as I too happen to currently reside in this scary place known only as "overseas"), nor do I own a standalone DAC that can take S/PDIF input.  My sole DAC is a Nuforce uDAC which is either used alone or to feed the Schiit Asgard which I just got (in anticipation of buying the HE-5LE, and to power my current HD 600).

 

I'm not interested in spending hundreds more on a testing rig (or the time to test it) - if it was something I could do for my master's thesis, sure... But I'm a mechanical engineer, specializing in applied mechanics.  At best I might be able to get away with something about speaker cone performance (breakup, resonance, etc.) or cabinet design - but I don't like doing vibrations work, honestly - nor is it my field of specialization.  Actually, I'm working on my thesis proposal now - it's going to be on the fatigue failure of bicycle spokes.

 

Since you already have it, why don't you get a friend to help you perform some blind tests?  I'm sure that others here would be happy to work out a procedure here with the equipment you have available.  I'd at least be willing to help with that.

 

 



Quote:
Originally Posted by nick_charles View Post


I've spent over 4 years researching this topic, I even joined the AES so I could trawl their library of papers. I've harrangued manufacturers and audio experts alike. Let us be quite clear, there is not one credible shred of empirical evidence to suggest that jitter in the magnitude and patterns as found in barely competent commercially available digital audio kit is in any way audible as a separate artifact. Random jitter adds noise which effectively lowers the resolution, signal correlated jitter adds distinct distortion sidebands. The only piece of audio kit that has verified jitter that even gets close to the most pessimistic threshold of audibility is the piss-poor McIntosh music server which Stereophile helpfully measured

 

http://www.stereophile.com/content/mcintosh-ms750-music-server-measurements

 

If ps of jitter are important then a system with this much jitter (14ns) should be utterly unlistenable. In fact while it is an awful piece of kit in absolute terms jitter is the least of its problems , it has IMD and THD 20 - 24db worse than its jitter distortion, still the Stereophile reviewer liked it until he was told how just how badly it measured then when he went back and compared it to another system and he then thought it a let-down - if I know it is bad I will hear it as bad - these golden ears crack me up right enough !

 


Well I must say that is impressive.

 

When you say "distortion sidebands" - I assume that's harmonics at specific frequencies that are related by some unknown function (that which the jitter imposes) to the input signal (or are a result of some other periodic source cause)?

post #393 of 438
Quote:
Originally Posted by nick_charles View Post



BB,  seriously do not get drawn in this, you'll buy the device, not hear any difference and when you report this LP will simply say that your kit is just not good enough or your hearing is defective/untrained !
 

If you try to get round this by recording samples from the analog out of your DAC (with and without the wonder device) to use in DBT or mathematical comparisons the recording device will not be good enough either. The massive (night and day) difference will somehow fail to survive the digitization process.

 

@Lee if I bought one of those Bravo devices and compared the analog out of my 24/96 DAC in four different modes - USB mode, Toslink mode,  USB---Bravo-----Coax mode and USB---Bravo-----toslink mode and performed careful recordings would you accept the FR differences measured from 20hz - 20hz as evidence for the impact (or not) of jitter  ?


Well I already posted...  Of course I'm not going to try - for the reasons you listed, of course, since they're always the reasons cited for any test that doesn't give the results that people want...  Oh, and my personal time/money reasons too.

 

I'd certainly be interested in and supportive of you or anyone else willing to perform measurements and/or blind testing of such things, however.

post #394 of 438
Thread Starter 



 

Quote:
Originally Posted by BlackbeardBen View Post

 

When you say "distortion sidebands" - I assume that's harmonics at specific frequencies that are related by some unknown function (that which the jitter imposes) to the input signal (or are a result of some other periodic source cause)?


Best way to show this is to point you to stereophile - their reviews of CD players include measurements of jitter which are graphed , they use a 1khz signal and you can see both distinct spikes and low level random noise. I do not think they are harmonics.
 

post #395 of 438

Leeperry, you are very good at suggesting links, but this becomes a self fulfilling prophecy for you. There is all that jitter, I can hear a difference, it must be the jitter causing it. You are the one with the kit, please blind test so that your ears and ears alone will be the final judge.

post #396 of 438

 

Originally Posted by BlackbeardBen View Post

I'm looking for empirical evidence, not testimonials

 

 

Well, Wolfson are IC makers and the companies using WM8804(Little Dot put it between the inputs and the DAC chip in their DAC's for instance, and so did Neko Audio. Also, all the newest A-GD units use it as well on their S/PDIF inputs) don't seem too interested in making studies either. Audiophile gear is very much a nice market, I surely don't want the prices to go up because of some huge studies taking place in order to make the skeptics peeps at the back of the bus happy(or unhappy, depending on the results [:gonc]).

 

Originally Posted by BlackbeardBen View Post

 

Since you already have it, why don't you get a friend to help you perform some blind tests? 


Coz I've got nothing to sell nor to prove...and whatever either of us will provide, he'll always be called on it...this thread is a giant troll feeding feast as far as I can see, as noone wants to lose face and will always provide any google link he fancies to prove his point.
 

Originally Posted by nick_charles View Post

 

If you try to get round this by recording samples from the analog out of your DAC (with and without the wonder device) to use in DBT or mathematical comparisons the recording device will not be good enough either. The massive (night and day) difference will somehow fail to survive the digitization process.

 

@Lee if I bought one of those Bravo devices and compared the analog out of my 24/96 DAC in four different modes - USB mode, Toslink mode,  USB---Bravo-----Coax mode and USB---Bravo-----toslink mode and performed careful recordings would you accept the FR differences measured from 20hz - 20hz as evidence for the impact (or not) of jitter  ?


Nick, sometimes you guys at the back of the bus don't seem as technically savvy as I would have though. First you test cables by doing SRN/THD/FR measurements, and call them all identical....when obviously, this could be apparented to eating soup w/ a fork. You'd need at worst an analog oscilloscope and at best a serious measurements package such as the AP in order to actually measure those differences:

http://www.google.com/search?q=cables+measure+differences&hl=en&source=hp&aq=f&aqi=&aql=&oq=

 

http://www.farraguttn.com/science/milligan/APPhys/AResLab.htm

 

http://www.cardas.com/content.php?area=insights&content_id=10&pagestring=Measuring+Cable+Resonance

 

"Unlike video cables, audio cables do not live in a matched impedance world. The wavelength of the audio signal is too long to establish a true transmission line. Impedance characteristics dance all over the place. This, combined with the necessary high impedance termination supplied by the audio components, creates a very poor situation. [..] Cables that look pretty good in the 75 ohm or 110 ohm, balanced world suddenly ring like a bell and become microphonic and misbehave in general. [..] Good interconnect cables measure like good capacitors. Cables that measure like bad capacitors, sound like bad capacitors."

 

 Test2cl.jpg Test2zip.jpg

 

Then you offer to capture the analog outputs of your DAC on a cheap USB soundcard(your Roland thingie?) in order to prove that jitter doesn't exist? Did I get this right? Many recent DAC's use ASRC because resampling lowers jitter drastically....this is exactly what you intend to do. This is nicht gonna work, and you will tell me that they all sound the same to you...yada yada [:j l b]

 

Anyway, you guys seem pretty happy w/ the gear you own, and all the cables sound the same too...how is that not a good thing?

 

And to get back to jitter audibility: http://www.avguide.com/forums/jitter-audibility-robert-harley-and-keith-johnson-comment

 

"Quote from the text linked above "Experiments were carried out in the listening booth or studio that each listener had offered. The examiner only brought there a personal computer with a digital audio interface and a mouse and each listener provided his or her favorite DAC, amplifiers and loudspeakers."
 
Knowing what we know about USB DACs and interfaces between portable computers and DACs, it's no wonder that jitter differences were masked by this inferior and highly variable interface methodology. Also these tests were done in 2005 when the quality of USB DACs was far inferior to today."

 

Do the same studies w/ the 46ps spec'ed $189 TC Konnekt 6, and I'll be more willing to take their results into serious consideration.

post #397 of 438

I am quite happy to 'lose face' and will go with the evidence. Leeperry, your technical knowledge is possibly the best of anyone here, but I still do not see a direct link between a measureable difference and audibility, I only see suggestions of one. And of course a refusal do do the one test that uses your ears alone to tell differences.

 

One of the links you posted lead to this;

 

http://www.avsforum.com/avs-vb/showthread.php?t=941184

 

a failed blind test between Monster cables and Opus MM cables ($33000 worth AFAIK).

 

The repeated failure to identify cables with the ears alone casts a huge shadow over all other claims about cables.

post #398 of 438
Thread Starter 



 

Quote:
Originally Posted by leeperry View Post

 

 

 

Well, Wolfson are IC makers and the companies using WM8804(Little Dot put it between the inputs and the DAC chip in their DAC's for instance, and so did Neko Audio. Also, all the newest A-GD units use it as well on their S/PDIF inputs) don't seem too interested in making studies either. Audiophile gear is very much a nice market, I surely don't want the prices to go up because of some huge studies taking place in order to make the skeptics peeps at the back of the bus happy(or unhappy, depending on the results [:gonc]).

 

 

Where are the DBTs that show that this technology makes an audible difference ? - this is a very simple question and one that you dodge again and again !

 

 

 

Coz I've got nothing to sell nor to prove...
 
Actually you are the one who insists that jitter is a problem when the prevailing empirical evidence is that it simply is not, therefore you are the one with the radical position that needs proof ! or alternatively you could accept that there is no proof and it is all audiophile flummery ?
 
 
EDIT: I just looked at the Firestone Bravo web page - you do know that they are not measuring jitter here that they are showing noise levels via a FR analysis , exactly what I have been talking about ! - So in fact while their device does show a lowering of noise you have no way of knowing how much of that was jitter to start with !
 
 


Nick, sometimes you guys at the back of the bus don't seem as technically savvy as I would have though. First you test cables by doing SRN/THD/FR measurements, and call them all identical....when obviously, this could be apparented to eating soup w/ a fork.

 

Lee, as I have repeatedly said, I am most interested in FR as that is the single most defining audio quality, it is the underlying tone of an item, surely you agree with this ?

 

 

You'd need at worst an analog oscilloscope and at best a serious measurements package such as the AP in order to actually measure those differences:

http://www.google.com/search?q=cables+measure+differences&hl=en&source=hp&aq=f&aqi=&aql=&oq=

 

No, not at all, anything that captures the FR will suffice, an ADC can do this very nicely ! - it does not need to be sophisticated to capture the FR

 

 

Then you offer to capture the analog outputs of your DAC on a cheap USB soundcard(your Roland thingie?) in order to prove that jitter doesn't exist? Did I get this right?

 

Of course not and you know it, of course jitter exists, how big it is and how audible it is are the questions - jitter shows up in deviations to the FR - we know this to be true, it has been shown again and again.

 

A signal with one level of jitter will look different from a signal with a different level of jitter, this is not rocket science you can prove this using audacity - feed the two signals in chart the spectra and you can mathematically measure the differences - this is easy, I've done this.

 

Your thesis that my capture device will not adequately capture the differences boils down to the fact that these night and day differences in jitter when reclocking are so insignificant as to be underneath the threshold of a 16 bit system - i.e the differences are smaller than 1/2 of an LSB of a 16 bit system i.e they are below the quantization error, do you really contend that deviations this low will be audible, you are talking about differences between the stimulae below -96db - really night and day stuff !

 

Say a nominal full scale signal is 2V , divvy that up by 16 bits and you get  0.000030517578125V per step - that is the difference adding 1 to the value makes so going from 0 to 1 goes from 0V  to 0.000030517578125V , however our quantization error is half that so the difference due to jitter must be below 0.015millivolts in orer to not be detected. This is the night and day difference you are talking about ?

 

 

 

 

any recent DAC's use ASRC because resampling lowers jitter drastically....this is exactly what you intend to do. This is nicht gonna work, and you will tell me that they all sound the same to you...yada yada [:j l b]

 

Lee, first you say this Bravo device will radically lower jitter by reclocking and thus make the sound much much better, now you say that this difference cannot be measured, that makes no sense, which is it - can the massive difference be measured or not - if it cannot be measured how do you even know it is working ?

 

 

 

Anyway, you guys seem pretty happy w/ the gear you own, and all the cables sound the same too...how is that not a good thing?

 

And to get back to jitter audibility: http://www.avguide.com/forums/jitter-audibility-robert-harley-and-keith-johnson-comment

 

Robert Harley  - seriously ?, the man whose understanding of jitter is so bad that he was routinely corrected and even incited Peter Aczel to get Bob Adams (Analog Devices) , someone who actually knows what he is talking about re jitter not some audio hack who got his job writing an essay , to write a proper article explaining jitter

 

 

"Quote from the text linked above "Experiments were carried out in the listening booth or studio that each listener had offered. The examiner only brought there a personal computer with a digital audio interface and a mouse and each listener provided his or her favorite DAC, amplifiers and loudspeakers."

 


 
Knowing what we know about USB DACs and interfaces between portable computers and DACs, it's no wonder that jitter differences were masked by this inferior and highly variable interface methodology. Also these tests were done in 2005 when the quality of USB DACs was far inferior to today."

 

This is from , er an audio hack isn't it ? - and his evidence is ......? well it is just speculation as usual. Where is the evidence, that jitter was masked by whatever not anecdotes ?

 

 

Do the same studies w/ the 46ps spec'ed $189 TC Konnekt 6, and I'll be more willing to take their results into serious consideration.

 

I have nothing to prove, others have provided good evidence, if you want to prove them wrong .....

post #399 of 438

Oh, Cardas says that resonance is a problem in audio cables.  I better believe them and disregard the truth then, since they know everything about cables and wouldn't try to hide any evidence that might show that their cables don't have any meaningful advantage over other cables.  They supposedly ring like a bell...

 

http://www.audioholics.com/education/cables/debunking-the-myth-of-speaker-cable-resonance

 

Let's do a little LC calculation (R is negligible) of the resonance of an interconnect.  Let's say you're using this one, since they give the capacitance and inductance per foot.  Let's also say that we're using a long four foot interconnect.  If you run the numbers through the LC resonance frequency equation for a four foot length, assuming the effect of the plugs is negligible as there's no mention of their performance (perhaps not an entirely sound argument, but the length of the plugs is tiny in comparison to the four foot cable) - you'll find that the resonance frequency for that particular interconnect is 25 MHz...  Not even close to audible frequencies.

 

About that Cardas link - that's a really lackluster description of the procedure (there's no way anyone could exactly duplicate what he did - which is absolutely vital if you expect anyone to take you seriously) - and is he really comparing the noise response of two cables with different input?  Someone who sells and "tests" cables should at least have the ability to output the same signal into two different cables at the same time (heck, put it out into mono with one of each cable) and record the exact same waveform for both.  He doesn't show any sort of scale either, so it's impossible to even see how much that is and if it really actually means anything.  Of course, this is coming from a cable manufacturer, so who knows to what level the procedure and results are biased...

 

As for measuring the SNR/THD/FR of cables, running the cable from the analog output to input of a DAC/ADC - explain how that is an invalid method of testing?  You're subjecting the cable to the exact same conditions as it will be in use, assuming the input impedance of the ADC is similar to that of amps - a fair assumption as every analog input today (preamp, amp, or ADC) has a high impedance input to facilitate voltage bridging.  Thus the performance parameters will be the same as when in real usage with an amp.

 

 

Quote:

Then you offer to capture the analog outputs of your DAC on a cheap USB soundcard(your Roland thingie?) in order to prove that jitter doesn't exist? Did I get this right? Many recent DAC's use ASRC because resampling lowers jitter drastically....this is exactly what you intend to do. This is nicht gonna work, and you will tell me that they all sound the same to you...yada yada [:j l b]

 

Anyway, you guys seem pretty happy w/ the gear you own, and all the cables sound the same too...how is that not a good thing?

 

Do you understand how measurement works?  Let's assume his ADC has produce a whopping 1 ns of jitter.  Let's also say he was to do testing of artificially generated jitter ranging from 1000 ns down to 50 ns.  Say that among that he does blind testing between 100 ns and 50 ns simulated jitter.

 

Now I'm not an expert on summing noise, but for argument's sake let's say when you run a signal through subsequent sources of jitter (the simulation, then the DAC), you add them together to get a total jitter range.  So for his 50 ns sample there should be 50 ns + 1 ns = 51 ns of jitter.  Likewise, for 100 ns of simulated jitter there should be 101 ns of total jitter.  A control sample would have 1 ns of jitter of course, as there's none synthesized.

 

If a DAC with 1 ns of jitter would be impacting the results of this test in a meaningful way - please explain how.  If the jitter of the DAC is covering up the induced jitter, explain how.

 

 

 

Quote:

And to get back to jitter audibility: http://www.avguide.com/forums/jitter-audibility-robert-harley-and-keith-johnson-comment

 

"Quote from the text linked above "Experiments were carried out in the listening booth or studio that each listener had offered. The examiner only brought there a personal computer with a digital audio interface and a mouse and each listener provided his or her favorite DAC, amplifiers and loudspeakers."
 
Knowing what we know about USB DACs and interfaces between portable computers and DACs, it's no wonder that jitter differences were masked by this inferior and highly variable interface methodology. Also these tests were done in 2005 when the quality of USB DACs was far inferior to today."

 

Do the same studies w/ the 46ps spec'ed $189 TC Konnekt 6, and I'll be more willing to take their results into serious consideration.

 

Well that's all fine and dandy that some random guy from a forum says that.  But how exactly did the USB to S/PDIF impact the performance?  Was its jitter too high?  What was its jitter?  Of course, they don't say what the interface used was, but are there even any USB to S/PDIF converters in existence with jitter that would make the difference between 500 ns and 250 ns insignificant?  What was the jitter of the DACs involved?  I hope that professionals in the industry are using DACs with jitter low enough that does not make the difference between 500 ns and 250 ns of jitter insignificant - and again, are there any DACs that bad in commercial production?  I feel like half the "audiophiles" on the planet would have a heart attack if there as a DAC sold as a professional or hi-fi product with, say 100 ns of jitter...  Yes, I agree that more details of that study would help solidify its conclusions as valid or invalid.  But with jitter levels that high undetectable I don't see how any even remotely competent USB to S/PDIF converter or DAC could possibly undermine that study.  The difference between, say, 46 ps and 1 ns (or even a bad 14 ns) on a remotely competent DAC when you're comparing 500 ns to 250 ns is entirely irrelevant to the test and will have no impact on the results.

post #400 of 438

an interesting question is now that digital audio with good crystal clocks, buffers, PLLs have reduced jitter by orders of magnitude vs older mechanical analog recording/playback with many microsecond to even millisecond "jitter" in tape stick/slip/scrape flutter and phonograph platter speed, tone arm/cart record warp driven resonance wow/flutter and cartridge tracking/tracing distortions all being expressible in terms of equivalent jitter - why the obsession Now?

 

analog tape "jitter" http://www.plangentprocesses.com/

 

phonograph "jitter": http://files.audiamorous.net/trackingerrorsimulator/poster.pdf - and paper http://files.audiamorous.net/trackingerrorsimulator/tollerton127stripped.pdf - with references to 50 year old phonograph playback distortion papers

post #401 of 438
Thread Starter 
Quote:
Originally Posted by jcx View Post

an interesting question is now that digital audio with good crystal clocks, buffers, PLLs have reduced jitter by orders of magnitude vs older mechanical analog recording/playback with many microsecond to even millisecond "jitter" in tape stick/slip/scrape flutter and phonograph platter speed, tone arm/cart record warp driven resonance wow/flutter and cartridge tracking/tracing distortions all being expressible in terms of equivalent jitter - why the obsession Now?

 

The anti-digital lobby needs a bogey-man, in the early days it was harsh recordings due to lack of familiarity with the new reqts of the technology, then it was some undefined gaps in the signal caused by sampling, jitter gives them a last gasp reason to be supsicious of digital.

 

From the pov of digital kit manufacturers jitter is a means to invoke panic and upgrading to the latest lower jitter CD player, for the add-on market there is the opportunity to sell something [see panic] to lower jitter, all of these constituencies advertise to some degree.

 

Also if you repeat something often enough eventually some folks will come to believe it.

 

If we look at Stereophile for example they will tut-tut a digital item with one ns jitter while giving a free pass to a TT with 1% speed error, funny really. Also many audiophiles have the same kind of OCD and neurotic tendences that golfers have and jitter naturally appeals to that, it is something they can think they are doing something about without ever having to rigoroulsy test whether it really matters or they can really hear it, brilliant really.

 

 

analog tape "jitter" http://www.plangentprocesses.com/

 

phonograph "jitter": http://files.audiamorous.net/trackingerrorsimulator/poster.pdf - and paper http://files.audiamorous.net/trackingerrorsimulator/tollerton127stripped.pdf - with references to 50 year old phonograph playback distortion papers

post #402 of 438

It's easy to forget that engineers are happy to oblige to design something that looks or measures better, even if they know it doesn't make any difference...  Whether it's pride, boredom, marketing, or just needing a reason to have their job, there's plenty of reasons to ignore the limits of perception.

post #403 of 438

nm.

post #404 of 438

 

Originally Posted by nick_charles View Post

 

Where are the DBTs that show that this technology makes an audible difference ? - this is a very simple question and one that you dodge again and again ! 


I dunno, maybe noone cared to make them? I'm not a PM for Wolfson...why don't you give them a call? Or send an email to the guy who wrote that AES paper(his email address is right on top of page 1): http://www.wolfsonmicro.com/documents/uploads/misc/en/A_high_performance_SPDIF_receiver_Oct_2006.pdf

 

The 75ps CS2000 used to be the top reclocker, but now the 50ps WM8804 has taken the crown...soon enough we'll see TI coming up w/ a 25ps reclocker I would guess. These are very cheap IC's that fix the clock jitter problem once and for all...except for the peeps at the back of the bus, it's a done deal.

 

Actually, TC in the PDF I mentioned earlier don't dismiss the reclocking approach to lower jitter....they simply state that they have a more cost effective and easier to implement solution. Reclocking gets the job done, though. If you ever get the chance to hear WM8804(and I surely hope you will), you might very well be stunned by the sound clarity improvement...especially when feeding a CS841x chip.

 

Originally Posted by nick_charles View Post

first you say this Bravo device will radically lower jitter by reclocking and thus make the sound much much better, now you say that this difference cannot be measured 

 

I never said anything like that, I'm sure you could measure the jitter improvement right off the DAC chip input/output...but not by resampling the DAC unit output to an arbitratry sample rate, resampling doesn't allow to measure jitter....much like the built-in ASRC of the Sabre DAC's, resampling is a dirty solution to jitter problems. It gets the job done, at the expense of increased THD/THD+N. And how tight's the clock of your ADC chip BTW? [:jyb34]

 

Originally Posted by nick_charles View Post

Stereophile for example they will tut-tut a digital item with one ns jitter while giving a free pass to a TT with 1% speed error, funny really. Also many audiophiles have the same kind of OCD and neurotic tendences  


Ahhhhh, you know stereophile, 6moons, computeraudiophile.com...to me they're what James Brown called "talking loud and saying nothing". Stereophile said that the STX had very low jitter at +800ps, they seem to be hoping that the ppl reading(paying for?) their fluff actually have a goldfish memory. It's got nothing to do w/ the fact that those Asus soundcards were on the magazine cover...nothing at all [:atom1ck]

post #405 of 438
Thread Starter 
Quote:
Originally Posted by leeperry View Post

 


Ahhhhh, you know stereophile, 6moons, computeraudiophile.com...to me they're what James Brown called "talking loud and saying nothing". Stereophile said that the STX had very low jitter at +800ps, they seem to be hoping that the ppl reading(paying for?) their fluff actually have a goldfish memory. It's got nothing to do w/ the fact that those Asus soundcards were on the magazine cover...nothing at all [:atom1ck]


LOL - I just this very day had an forum interchange with John Atkinson, somewhere else, he pointed me to SP reviews of 2 USB DACS, the 2nd of which was the HRT Streamer which HE described as having  moderately high levels of jitter, the Miller Analyzer calculating there to be 720 picoseconds peak–peak of jitter-related sidebands in the analog output signal
 

tomato tomaytoe ? 

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