Jitter article
Comments
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Sami wrote:That's very obvious, and that's not the issue here. What you haven't explained to me is why would two devices sound different if they are both connected to the same DAC, delivering the same information?
Answer: Higher jitter in the cheaper component due to cost constraints.
Error correction has 2 effects, either you hear it (a "pop" "click" or skip) or you don't. Error correction does not degrade the signal if it is successful (inaudible). In other words, either the error correction is succesful, and you hear nothing adverse; OR it's unsuccessful and there will be no doubt when it happens (very audible).Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2 -
steveinaz wrote:Answer: Higher jitter in the cheaper component due to cost constraints.steveinaz wrote:there will be no doubt when it happens (very audible)
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Sami wrote:Yes you have.
Your post before about the signal interference, while possible, could be avoided by error correction. Whether the design of the transfer protocol takes care of it or not is something I was wondering. If we can transfer bit-perfect data over the air with error correction it certainly would be possible with the computer via a cable. But that all depends on the specifications on how the data is transmitted to the DAC.
Error correction CIRC (Cross Interleave Reed-Solomon Circuit) which is the standard has nothing to do with signal inteference via the cable or noisy fans or poor power regulation. Error correction either interpolates or extrapolates (or both) bits of info to replace damaged or missing info (at the time of extraction). As Steveinaz said, it's either very obvious as in pops and clicks when too much info is missing or damaged or it's completely transparent and you won't know when the circuit is correcting.
Your statement about there being no noise in a computer environment is simply not true. Maybe you don't hear it or notice it or care about it, but it's there. A computer is not the ideal environment to reproduce audiophile sound compared to a seperate stand alone rig.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
heiney9 wrote:Your statement about there being no noise in a computer environment is simply not true. Maybe you don't hear it or notice it or care about it, but it's there. A computer is not the ideal environment to reproduce audiophile sound compared to a seperate stand alone rig.
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Sami wrote:Not the answer if jitter only occurs in DA conversion.
It doesn't. Jitter occurs from the transports clocking crystal (inaccuracies) and is transferred via your digital cable TO the DAC. Remember, no crystal clock is 100% accurate, hence timing errors (aka: jitter).Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2 -
Unless you have an extremely well built, very high quality computer, chances are you'll be introducing additional jitter because of internal noise, rf interference, etc.
Try this, turn your computer speakers all the way up....hear any buzzing, humming, erroneous sounds?Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2 -
steveinaz wrote:Try this, turn your computer speakers all the way up....hear any buzzing, humming, erroneous sounds?
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steveinaz wrote:It doesn't. Jitter occurs from the transports clocking crystal (inaccuracies)
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That's probably why you're not hearing a difference. Could be that your card and CDP are fairly close in relation to measured jitter.
What is the rest of your audio system?Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2 -
Sami wrote:Now that must be then a fault in the design of the path to the DAC then, or the CD format. If inaccuracies can be fixed in the transport of data, why not in this case?
That's the problem, no one has come up with a way to eliminate jitter (timing errors), though your more expensive transports minimize it quite a bit. Also alot of external DAC's implement "jitter reducing" circuits to help minimize the problem. This is why your better external DAC's are expensive and work very well for most.Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2 -
steveinaz wrote:That's the problem, no one has come up with a way to eliminate jitter (timing errors), though your more expensive transports minimize it quite a bit. Also alot of external DAC's implement "jitter reducing" circuits to help minimize the problem. This is why your better external DAC's are expensive and work very well for most.
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Sami, no dis-respect intended but you need to do a Google search as the scope of your inquiry is way too large. Sounds as if you are trying to equate digital audio concepts to computer digital concepts and they are very different environments with two very different results. I don't pretend to know in depth info about either, just what I've read/researched over the years. You have some good insights, but I'm not sure anyone here is completely qualified to answer all your questions.
Also FYI, there is no buffering stage in the DAC audio chain and and some of your concepts, though logical, just aren't applicable.
FWIW
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
Here are a couple of articles that might help:
Audio Compact Disk - An Introduction. Use the 'Next' link at the bottom of the page.
CD Jitter -
jmierzur wrote:Here are a couple of articles that might help:
Audio Compact Disk - An Introduction. Use the 'Next' link at the bottom of the page.
CD Jitter
So far the Jitter article is a good read. I'd say mandatory for those interested.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
Also keep in mind the Jitter article points out some faults that are specific to the Phillips unit they are discussing and may not affect other 1-box systems or 2-box systems in the same way.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
On the computer side, there are programs that have jitter correction.
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heiney9 wrote:Sami, no dis-respect intended but you need to do a Google search as the scope of your inquiry is way too large. Sounds as if you are trying to equate digital audio concepts to computer digital concepts and they are very different environments with two very different results.
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Sami wrote:... I just said that it would be possible to do the transfer bit-perfect, just that the technology doesn't exist. If jitter was a major problem then the technology would already be here...Win7 Media Center -> Onkyo TXSR702 -> Polk Rti70
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Sami wrote:Well, I thought reading between the lines was pretty obvious but I guess I left too much open. Notice how I said IF many times. The realtime transfer was something in my head, I just said that it would be possible to do the transfer bit-perfect, just that the technology doesn't exist. If jitter was a major problem then the technology would already be here. I just think that jitter is one of those things that aren't important, just like expensive cables. Irrelevant to audio quality.
You are certainly entitled to your opinion. There are certainly many components responsible for digital to analog conversion. Using top notch parts and a good design is really the key and don't kid yourself this approach is very costly. Jitter just by itself is not an issue if the rest of the components/design is poor and uses inferior parts to be cost effective. Decreasing jitter in that case is a complete waste of time as there are many other issues that would contribute to inferior sound reproduction. As you move up the audio chain jitter suppression IS an issue and any good designer of a CDP or stand alone DAC has to take nec steps to reduce jitter as much as possible. High levels of jitter are always going to be present in inexpensive CDP's/DVDP's and inside an AVR that has digital input/output.
This is my final word/opinion on the subject. To simply say jitter is nothing to be concerned with is very short sighted. But we are all in different places on our audio journey and experience/listening is the best tool.
Happy Holidays
H9
P.s. Let's not even go down the "expensive cable" path. Did you participate in the cable swap program?"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
TheReaper wrote:The technology has existed for 15 years. I doubt there is a current mainstream surround receiver that still uses a PLL between the digital input and DAC.
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heiney9 wrote:As you move up the audio chain
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OMG! I don't care about the flames I'm gonna get for this one. I can't stand reading the Qs and (sometimes helpfull) As over this subject (not just jitter here, but digital signals in general)......
First off, if your source is DTS or DD, then the data is sent in packets and any loss of data will hopefully be not noticed by the listener. If it's PCM, then any loss of data will only be noticed if the error correction used couldn't correctly recreated the missing data enough. So under conditions with no errors, it doesn't matter if you're using coax or fiber, jitter or not you will get what was intended to be heard. Under conditions that generate errors in DD or DTS, you might experience a drop out of sound for a moment as the packets with errors are discarded and the decoder gets back in sync with current packets. If the source is PCM, then errors in transmission can be more noticable. The decoder will try to use previous data to fill in the missing data. You don't get the benefit of a drop out in sound as with DD or DTS. Instead you will either get a decent correction from the decoder or a not so decent correction that will be quite audible (pop, click, etc.). Jitter is not as much an issue as some would have you believe. Think back to when some of the same individuals sang the praises of marking your CDs with a green marker.
Now to touch on the subject of coax over fiber. I have come to the conclusion that no matter what, or from who the reply comes from, the facts will never be realized. How someone can hear a difference between coax and fiber to the same decoder still confuses me. I don't care if one can prove that the fiber connection is top quality or middle of the road.... If the digital stream makes it from point A to point B intact, then the decoder will create the exact same analog signal for the amp circuits. If it can't, then you'll sure and hell know it. For argument sake, I had a friend that sings opera professionally listen to a recording played over both coax and fiber and they couldn't tell the difference. I then placed a mark on the disc to create an error and both the coax and fiber created the same sound reproduction error. They were able to tell and also state that there was no difference in the sound reproduction error between coax or fiber.
I think before anyone comments on, tries to explain or explain the digital transmission process they stop and think about whether they actually are qualified to do so. The limit of discussion about coax and fiber should be in regards to run length, cost or quality of construction. Remarking about how the coax sounded better than the fiber is BS if it's based on error free audio. There will not be a difference other than what the listener is using as a bias.
Okay, flame away. I'm ready. My 20+ years working with digital transmissions and receiving/decoding can take it.Driver carries only 20 dollars in ammunition
Pedestrians have the right of way, unless they are in the way -
Well, there it is. The audio industry can quit trying to solve this non-existant problem, and the rest of us can stop worrying about it because it doesn't really exist. Finally, those of us who are not experts can stop our futile attempts of educating ourselves through discussion, because we really don't know what we're talking about in the first place. It's doubtful we'd learn anything anyway. Whew, ignorance is bliss, thanks.Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
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steveinaz wrote:Well, there it is. The audio industry can quit trying to solve this non-existant problem, and the rest of us can stop worrying about it because it doesn't really exist. Finally, those of us who are not experts can stop our futile attempts of educating ourselves through discussion, because we really don't know what we're talking about in the first place. It's doubtful we'd learn anything anyway. Whew, ignorance is bliss, thanks.
I was going to be done with this thread, as I've said as much as I can. I still think Sami and I are going down 2 entirely different paths in the discussion, but.............
+1 to Steveinaz
Tugboat, I think you missed the boat ...so to speak. I wasn't nec challenging the notion of digital transfer being all that different in like situations. My big point is when analog conversion is involved. I never said moving digital bits from 1 place to the other caused/incurred all the problems discussed in this thread. I still feel, however, a computer environment is not the best place to extract audio data because of what I've referenced in earlier posts.
Jitter is an issue and reducing it is worthwhile in the analog world!
Happy Christmas & Merry New Year
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
Damn, too many martinis when I wrote that. Ooops. That'll teach me to reply to something I haven't read and understood. My fault. Sorry for that. My GF got me to drink too much and then let me on the computer. Please ignore my post and hope I didn't upset anyone too much.
ThanksDriver carries only 20 dollars in ammunition
Pedestrians have the right of way, unless they are in the way -
tugboat wrote:Damn, too many martinis when I wrote that. Ooops. That'll teach me to reply to something I haven't read and understood. My fault. Sorry for that. My GF got me to drink too much and then let me on the computer. Please ignore my post and hope I didn't upset anyone too much.
Thanks
I'm hoping those were Vodka martini's and I really hope the GF took advantage of you. Just got back from a family x-mas eve and I likes my martini's (Vodka that is). Gotta do the other side of the family tomorrow so that means more Vodka and my Uncle love Black Russians (the drink) so I must sleep now to prepare for tomorrows festivities.
Good night too all
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
I drink and surf all the time...!!! Its legal ya know;>)***WAREMTAE***
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Sahara dry Belvedere martinis. GF can only take advantage of me with Jack Daniels or Jim Beam. Not well equiped to handle whiskey for some reason. Doesn't take much of that to blackout. ) Vodka is so kind to me.
I drink and surf as well (as it's plain to see from my previous ill prepared reply). I should put one of those breath interlocks on my PC. If I blow over the legal limit, it will only start up and let me play Doom.Driver carries only 20 dollars in ammunition
Pedestrians have the right of way, unless they are in the way