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Originally Posted by wavoman /img/forum/go_quote.gif
linuxworks -- since as you say in the real-world S/PDIF bit errors just don't happen, why not just always use it?
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bit errors are almost zero, but that's not to say that timing errors are at zero. that's the whole broo-ha-ha (lol) about jitter.
but if you could 'wrap' the data with timing built in, the whole idea of jitter goes away. if you actually timestamped data (think of a graph of x,y points) then the dac would simply 'wait' until the timestamp elapsed and then squirt out the word (converted to analog level) at the right time. that would be the short of it
spdif has no timing built in, just 'this is a pulse and this is pulse n+1'.
not quite the same as having real actual timestamps per value.
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| Especially if your sound card (like the moon-audio modded MAudio 192) uses a transformer on the output as you suggest. |
transformers don't cut down on errors or change timing. they only allow some natural noise reduction to happen and also remove dc bias from the lines. that's about it.
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| Toslink glass is expensive; toslink plastic has bend issues and maybe a higher chance for errors, no? So forget it if other options are available. |
IS there such a thing as toslink glass? I never heard of that. toslink is designed from the start to use plastic and not glass fiber. this isn't fddi or atm here
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| Also quoting you, AES/EBU has no advantage except longer runs over S/PDIF, and real 110-ohm XLR cables are not the standard mike stuff we have lying around. So why bother? |
because in a pro studio, they'll have a lot more radiated noise than usually you'll find at home. and also they tend to run multichannel which has crosstalk issues (digital interference which usually can get ignored but if you compound it, it makes it harder to sift signal FROM the noise). running higher voltages helps with that and mostly lets longer cables work.
oh, also, aes uses the better connector, in that it won't twist around (like rca does) and also is physically more robust. pros will unplug things more than consumers will, generally.
it makes sense for studios to use better connectors and such.
for us 'plug and forget' guys, though, an rca connector will usually do just fine
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| Now USB could be super, in theory as you say, but the actual implementations out there ... well who knows? |
they do vary but some are reported to be a lot better than just wrapping audio in a one-way stream. those are the good versions that people are trying to seek out.
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| I found one instance of an audio USB receiver software module on the web, and it did some decent buffering, and I do believe better DACs re-clock ... but I think all this just makes up for horrid audio isochronus USB-out firmware on PCs. |
usb audio is a good first pass at solving the problem. it has more refinement before its perfect, but it has the *potential* to exceed the one-way shipping nature of spdif.
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| 1. If your sound card has S/PDIF out, use it. |
I certainly don't go out of my way to AVOID spdif. I have no problem with spdif, really.
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2. If you only have USB out, and your DAC takes USB, that's that.
3. If your DAC does not take USB, and you only have USB out, the off-the-shelf USB-to-S/PDIF converters will work fine |
yup, agreed.
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| No reason to use optical unless that's all you have. |
I don't hate toslink
I have never broken it, I've bent it a few times but its not as critical as glass fiber. its not easy to terminate to custom length but these days, its cheap enough to just buy in lengths at monoprice. when opto cables were $20 and up, I hated them. now they are dollars (not tens of dollars) and so its fine.
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| All of these will sound the same I would think. We can test this: I have the S/PDIF sound card mentioned above, but of course I can bypass it and use USB. DAC has both inputs. Also have USB-to-S/PDIF converter. Which of the three options will sound the best ... will there be any differnece? |
I've never heard any one 'interconnect' sound better or worse. are my dacs good? are my ears bad? all of the above?
who knows. but I am not religious about my digital cabling; whatever connects is fine. my popcorn hour is native coax, so I 'do coax' to it. my pc uses a gamma1 which gives me both but I tend to connect opto from it, just to keep 2 things easy to find on the back of my dac or switch.
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| I tried this on Sunday over and over, all the combinations. No audible differences whatsoever, at least for me. |
usually, same here.
I've heard and can identify analog audio problems. digital 'timing problems' are elusive and hard to identify or describe or even measure! I'm not sure I've heard sound that was bad due to the digital audio connection method. some people swear they can tell. I've heard one guy tell me he can tell the diff between audio 'clocked' out of a spinning hard drive vs audio 'clocked' from a solid state drive. boggle! but some people are convinced. not sure how to respond to that
