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Optical TOSLINK vs. USB: Which connection is better to connect a DAC? - Page 5

post #61 of 105
Quote:
Originally Posted by grokit View Post

 

 

Wow, what a Richard's nicknamish post. Evidently you are incapable of learning and have to make things personal. To quote from one of the links from which you evidently know better than:

 

"Instead of impulses, usually the sequence of numbers update the analogue voltage at uniform sampling intervals.

These numbers are written to the DAC, typically with a clock signal that causes each number to belatched in sequence, at which time the DAC output voltage changes rapidly from the previous value to the value represented by the currently latched number. The effect of this is that the output voltage is held in time at the current value until the next input number is latched resulting in a piecewise constant or 'staircase' shaped output. This is equivalent to a zero-order hold operation and has an effect on the frequency response of the reconstructed signal."

 

 

 

 

Your posts are worthless. Probably all of them are it seems.
 

What does your paragraph have to do with latency? Your paragraph talks about general quality loss from converting squarewave signal into sinewaves. Of course, it has an effect on FR, and what about it? :D

 

Mate, you need to get a referencing lesson from 00904, and stop linking worthless wiki posts that are off topic anyway.


Edited by Drake22 - 3/8/11 at 2:30pm
post #62 of 105

From a practical standpoint, the issues with USB, such as noisy power from a computer, can be fixed by using an isolated power supply. The limitations of optical can not, at least by the end user.  The Lampizator site has some images from a scope of an optical S/PDIF signal and it is far from being a square wave.

post #63 of 105
Quote:
Originally Posted by Currawong View Post

From a practical standpoint, the issues with USB, such as noisy power from a computer, can be fixed by using an isolated power supply. The limitations of optical can not, at least by the end user. 



Good point...as well a USB DAC that can strip out the time domain and re-clocks it back in with minimal jitter can then take USB sound to the next level (as experienced when I moved up from my PS Audio DLIII to my Cary XCiter). The biggest difference in SQ was via USB input.

post #64 of 105

 

Quote:
Originally Posted by Drake22 View Post

Your posts are worthless. Probably all of them are it seems.
 

What does your paragraph have to do with latency? Your paragraph talks about general quality loss from converting squarewave signal into sinewaves. Of course, it has an effect on FR, and what about it? :D

 

Mate, you need to get a referencing lesson from 00904, and stop linking worthless wiki posts that are off topic anyway.


At least I cite my sources, and I'm not attacking you personally rolleyes.gif

 

I'm just trying to point out misinformation, like when you posted this gem:

 

"Jitter? That is just latency and it doesn't have any effect on the character of the sound.

There is no difference in sound between usb, optical, coaxial or hdmi. It's ridiculous to state otherwise."

 

What my previous post did was describe the part of the audio clocking dynamics that can create jitter, and cause errors in the resulting sound. I also think that optical s/pdif carries more jitter than coaxial s/pdif, and that jitter can absolutely have an effect on the character of the sound. These are my opinions, and I can cite multiple references them. But somehow I have a feeling that would be a waste of time, as they would be lost on you. 

 

I don't know who "00904" is but I haven't found anything wrong with what 00940 is saying. From the Apple page he referenced, it says that we need to increase buffer size to decrease latency, because latency can have a negative effect on the sound:

 

"Lower buffer sizes and higher sample rates may result in less monitoring latency, but these settings require more computational power. If you set the I/O buffer size to a value too low for your computer to handle smoothly, you may hear dropouts, clicks, pops or other artifacts in the audio."

 

Can you please cite a factual reference for your opinions, without the unnecessary hostility?

 

Peace Out smile.gif


Edited by grokit - 3/9/11 at 2:44am
post #65 of 105

 

Originally Posted by grokit View Post

 

unnecessary hostility?

 

Yeah, ppl act like fourth grade kids when it comes to audio...I don't think I'll ever understand why.

 

Anyway, going fully async does seem to changes things: http://www.lavryengineering.com/lavry_forum/viewtopic.php?f=1&t=979

 

"the measurements are virtually identical with any of the inputs- USB, XLR, RCA, or Optical"

 

A friend of mine has ripped SACD's digitally like this:

 

1) DSD internally converted to a 24bit/88.2KHz PCM stream by the Oppo DV-980H player
2) The PCM stream is conveyed into a high-quality HDMI 1.3 cable
3) The HDMI is connected to an Octava 1x2 HDMI Distribution Amp with Toslink Out
4) The PCM stream is splitted into a toslink cable
5) The toslink cable is connected to a M-Audio Transit USB adapter
6) The PCM stream is captured by Cockos Reaper 3.1x using the M-Audio ASIO drivers.
7) Final track splitting (no other editing is involved) is done in Reaper.

 

Yeah, it did go through POF toslink...and yeah, it sounds amazing! I could even provide a 30" sample.

 

Our empirical experience is based on cheapo DAC's with poor jitter tolerance, and isochronous USB transports. Or maybe they didn't measure the right stuff, but if there's someone I trust in the digital audio world that's Mr Lavry.


Edited by leeperry - 3/9/11 at 6:14am
post #66 of 105

I think that the whole of Leeperry's link to Lavry Engineering is worth reproducing....

 

".I consult your expertise in this area as this place are backed by solid scientific papers. Having read the skin effect on cables as well as comments by Mr Lavry regarding over-priced digital cable, I would like to know whether this applies the same for USB Cable.

Does a reasonably well built usb cable perform as well as it's much more expensive counter-parts? There have been lots of review stating 3 and even 4digits priced usb cables transforming a sound system. However, it's my understanding that async code place the re-clocking task on the converter and thus it does not depend on the quality of the usb cable...

We have seen no scientific evidence to this effect. When the DA11 is tested, the measurements are virtually identical with any of the inputs- USB, XLR, RCA, or Optical. And we do not use an expensive esoteric cable for the testing. I cannot comment on other designs.

There are other factors when using a USB source that are more likely to have an audible effect on the audio; like software interactions or other high-bandwidth devices sharing the same USB port.

There is definitely one way in which these expensive USB cables do transform the sound systems- by making the system more expensive.

Brad Johnson
Lavry Engineering Technical Support"

 

So, according to Lavry, if you buy a DA11 it makes no difference, to answer the OPs question. I suspect that is true of other DACs as well.


Edited by Prog Rock Man - 3/9/11 at 8:06am
post #67 of 105

 

Quote:
Originally Posted by leeperry View Post

 

Yeah, ppl act like fourth grade kids when it comes to audio...I don't think I'll ever understand why.


It seems to happen mainly in three areas: Sound science/DBTs (especially cables), digital/jitter/1's and 0's, and "to Apple or not to Apple"

 

What I have learned so far is if you have an asynchronous master audio clock outside the computer you can eliminate many problems related to jitter, including whatever your method of transmission is; USB, spdif or what have you. If you are using adaptive or even isochronous protocols where the computer controls the master audio clock you are asking for trouble, and USB/toslink can expose the most flaws compared to other methods of digital transmission. But the DA11, like the Streamlength codec and other asynchronous master clocking/re-clocking methods are providing a remotely-based master audio clock and are therefore reducing or eliminating the possibility of timing errors.

 

I love it when the manufacturer/designers weigh in. I am very interested in what Mr. Johnson/Lavry has to say about these matters, and am a big fan of Gordon Rankin as well. But I also realize that these guys have something to sell, and they (most likely) truly believe that their own product(s) has solved these issues in the very best way. I believe what they are saying for the most part but at the same time I also realize that every "problem" in this area has more than one possible solution.

 

As far as cables go, there are so many people that report clear auditory differences with a "better" USB cable that I want to try one sometime (within reason of course). Maybe with better DACs it doesn't matter as much; I would like to conduct my own experiments regarding this sometime, on my own setup(s) because that is really all that matters to me. When I replaced my cheap toslink cable with a glass one it improved the sound out of my DAC2 more than adding an external clock did, but on my Mini-i the results were pretty much the opposite.

 

I know I have come around to the benefits of upgraded headphone audio cables (against my better judgement), so it makes sense to me to give the digital cable an upgrade at some point to see if I can hear the difference for myself. It would be a final tweak though, after everything else is optimized. If it's placebo so be it, as long as I get some imagined benefit that works for me it's all good!


Edited by grokit - 3/9/11 at 11:58am
post #68 of 105
Quote:
Originally Posted by grokit View Post

 


It seems to happen mainly in three areas: Sound science/DBTs (especially cables), digital/jitter/1's and 0's, and "to Apple or not to Apple"

 

What I have learned so far is if you have an asynchronous master audio clock outside the computer you can eliminate many problems related to jitter, including whatever your method of transmission is; USB, spdif or what have you. If you are using adaptive protocols where the computer controls the master audio clock you are asking for trouble, and USB/toslink will expose the most flaws compared to other methods of digital transmission to the DAC. But the DA11, like the Streamlength codec and other asynchronous master clocking/re-clocking methods are providing a remotely-based master audio clock and are therefore reducing or eliminating the possibility of timing errors.

 

I love it when the manufacturer/designers weigh in. I am very interested in what Mr. Johnson/Lavry has to say about these matters, and am a big fan of Gordon Rankin as well. But I also realize that these guys have something to sell, and they (most likely) truly believe that their own product(s) has solved these issues in the very best way. I believe what they are saying for the most part but at the same time I also realize that every "problem" in this area has more than one possible solution.

 

As far as cables go, there are so many people that report clear auditory differences with a "better" USB cable that I want to try one sometime (within reason of course). I know I have come around to the benefits of upgraded headphone audio cables (against my better judgement), so it makes sense to me to give the digital cable an upgrade at some point to see if I can hear the difference for myself. It would be a final tweak though, after everything else is optimized. If it's placebo so be it, as long as I get some imagined benefit that works for me it's all good!


Grokit, another issue is the quality of the equipment the person has.  If it is higher quality equipment, than things like the differences in digital sources will be more apperent as will differences in cables themselves.  It seems to me that the people making the more childish type of arguments don't have access to equipment that will perform at the level necessary to detect changes in sources or cables.
 

 

post #69 of 105

 

Quote:
Originally Posted by mikemalter View Post

Grokit, another issue is the quality of the equipment the person has.  If it is higher quality equipment, than things like the differences in digital sources will be more apperent as will differences in cables themselves.  It seems to me that the people making the more childish type of arguments don't have access to equipment that will perform at the level necessary to detect changes in sources or cables.


Totally agreed, I was just editing my post to reflect that better components can either accentuate these differences or even sometimes negate them, depending upon what the tweak is. All of this is very inter-dependent with the quality of the component(s), and the rest of the setup as a whole. You're to quick for me!

post #70 of 105

For both USB and Optical there is another aspect that definitely influences both and that is the Tx/Rx modules in both the source and destination devices.

If the units are poor quality they can affect the signals in negative ways.  I think many times people do not consider these units although they do have a significant affect on the signals.

post #71 of 105

 

Originally Posted by grokit View Post

 

it makes sense to me to give the digital cable an upgrade at some point to see if I can hear the difference for myself. It would be a final tweak though, after everything else is optimized.


All cables color the sound drastically IME....but I run an adaptive USB transport, so you know.

Anyway, this thread is useless w/o samples [:hugeq:1]

 

04 - Thriller.flac

06 - Billie Jean.flac

 

These are 30" 88.2/24 samples of the Thriller SACD, and I've got no problem believing this quote: http://www.avsforum.com/avs-vb/showpost.php?p=19187517&postcount=6

 

"The Thriller SACD is the best version ever released of the album. Steve Hoffman has said it sounds the closest he has heard to the master tapes."

 

Toslink sounds horrid on my PCM1793/DIR9001/CS8414/WM8804 gear...the trebles are mushy, the sound is audibly smeared(poor clock extraction?). Nothing works better than an uber-short coax wiring IME. The 2 samples I just posted did go through a 1m POF toslink cable, would you say that they sound "bad"™? [:arantheus]

post #72 of 105
Quote:
Originally Posted by ROBSCIX View Post

For both USB and Optical there is another aspect that definitely influences both and that is the Tx/Rx modules in both the source and destination devices.

If the units are poor quality they can affect the signals in negative ways.  I think many times people do not consider these units although they do have a significant affect on the signals.


For optical cables, glass is better than plastic and it puts it in the range of coax.  Get glass fiber, it's a little more expensive, but there are some deals out there.
 

 

post #73 of 105
Quote:
Originally Posted by mikemalter View Post




For optical cables, glass is better than plastic and it puts it in the range of coax.  Get glass fiber, it's a little more expensive, but there are some deals out there.
 

 

I have quite a few optical cables, some glass and some plastic.

 


Edited by ROBSCIX - 3/9/11 at 6:14pm
post #74 of 105
Quote:
Originally Posted by ROBSCIX View Post



I have quite a few optical cables, some glass and some plastic.

 


Rob, what are your experiences with optical vs. plastic?
 

 

post #75 of 105
Quote:
Originally Posted by mikemalter View Post




Grokit, another issue is the quality of the equipment the person has.  If it is higher quality equipment, than things like the differences in digital sources will be more apperent as will differences in cables themselves.  It seems to me that the people making the more childish type of arguments don't have access to equipment that will perform at the level necessary to detect changes in sources or cables.
 

 



what, like, dedicated measuring equipment?

 

oh! you meant a fancy hi-fi! biggrin.gif

 

stop embarrassing yourself.

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