[Fungi]

Quote:

Originally Posted by HeadLover /img/forum/go_quote.gif not correct It is just like saying: "if I connect two computers, the speed will always be the same - 0,1" NOT TRUE !! The line itself have many things to do with it, every one that design a network know what I mean so I guess the same goes for audio Bad cable will lead to retransmit of data, and that will lead to bad audio at the end

Wait, you're asking whether coax or toslink is better and now you're telling people how cables work?

 

[HeadLover]

Quote:

Originally Posted by Fungi /img/forum/go_quote.gif Wait, you're asking whether coax or toslink is better and now you're telling people how cables work?

I have asked what is better, doesn't meant I don't know how things work

Beside, science is one side and audio is the other, most people that are only into science like I do will tell u that a 50$ interconnect is the same as a 1000$
so?
Is it true?
Maybe for them, but for most audiophil not

 

[wavoman]

bigshot -- "capable" of bitperfect, yes, but in practice probably not bitperfect. However the errors are likely to be inaudible, which is what you mean by "virtually identical" in your other post I believe.

So I think we agree in general, but in a third post you claim you got bitperfect DTS. Are you sure? I bet you got correctly encoded DTS which is why there are no DTS errors, but clearly a change to audio data is not an error to DTS, just different music, and if you got a bit flip, which you might in a real-world environment, then you couldn't hear it, but it wasn't bitperfect.

Total garbage TOSLink and USB cables exist, and can lead to errors that are audible. In other threads we have agreed: buy a reasonable brand name, don't overspend, but don't buy $1 cables.

This logic applies to digital cables only. It's not just the bits, but the timing too, as many other posters have said. That's why there are errors. But typically inaudible.

People who seem careful in their testing do claim however that they hear differences in better digital cables. They must have extremely noisy (electrical) conditions ... what else, I dunno.

As for coax vs TOSLink, the answer is to listen (and sell the cable you won't be using on eBay if you want). So easy to do in your own home. Some of the posters here did just that!

Since it all depends on the components, the environment, and the actual cable, the experience of others is of little guide. But if you must proceed without a test, then the typical "voice of the masses" answer is: from a PC use USB or Optical, not S/PDIF coax. From a CDP use AEU/BES or S/PDIF coax (BNC preferred over RCA, although some debate that), not Optical.

 

[compuryan]

You can talk about how digital is digital and it doesn't matter. But people spend lots of money on digital ICs, so it can have an effect, even if its subtle. The blue jeans cables are sufficient for my digital coax needs.

As for optical vs. coax there is very little discernible difference (if any) IMO. But I like coax because it just seems simpler. I also feel it might be more durable than the cables made of glass.

 

[Slaughter]

Quote:

Originally Posted by HeadLover /img/forum/go_quote.gif not correct It is just like saying: "if I connect two computers, the speed will always be the same - 0,1" NOT TRUE !! The line itself have many things to do with it, every one that design a network know what I mean so I guess the same goes for audio Bad cable will lead to retransmit of data, and that will lead to bad audio at the end

If you want to use a computer analogy, if I send a file to another computer over USB or Ethernet, the result is the same on the other end. Then you go on to mention a bad cable, but that is not the question here, it is whether a working optical cable and coax cable sound the same and yes they do. And interconnects are different as we are now talking about internal DAC's and an analog signal.

compuryan - Just because people spend money on them doesn't make it right. People with money will buy anything. Take Potterybarn furniture, there are only like 3 manufacturers of furniture in the entire USA, Potterybarn is somewhat expensive, but you can find their furniture in other stores rebranded for 1/3 of the price. Would people with money buy it, nope, because the Potterybarn brand lasts longer and has a name on it

 

[wavoman]

Sending a file does not have a hard real-time requirement. The file transfer methods use error checking and buffering to recover from transmission problems. So do some of the ethernet and WiFi based digital audio transmission methods, but they can't always re-transmit in time before the buffer empties, since you gotta do it before the music stops.

Straight digital audio transmission over optical or coax S/PDIF does not have all this logic behind it. Transmission errors can and do occur. Most are inaudible.

The file transfer analogy is not a good one. The zeros and ones have to be transferred under a tight time constraint during digital audio transmission, which is not the case during a fie transfer

 

[hohum]

Right, I have a question. Consider the following situation:

1. You want to use a PC as an audio source, and have the option of either coaxial or toslink
2. Also, let's pretend that both have been implemented well at the hardware level

Which would be the preferable option, considering PCs are viewed as a noisy source? Would coaxial still be 'better' despite it being susceptible to EMI/RF interference from the PC, whereas toslink isn't?

That's what I would love to know. Personally, I prefer the idea of using coaxial as it just seems more durable/reliable overall (based on opinions I've read). However, if toslink is going to produce 'cleaner'/more accurate audio when used with a PC source, then I'd have to opt for that one for obvious reasons. Any thoughts on this?

 

[philodox]

Quote:

Originally Posted by bigshot /img/forum/go_quote.gif A component with poor toslink implementation would be a problem with the component, not the cable. Both types of cables are capable of transferring bit perfect sound.

And I thought his question was if he should use Coax or Toslink. I am comparing the two formats, not the two types of cables.

Let me see if I can find that link I was talking about.

 

[I<3SQ]

Quote:

Originally Posted by HeadLover /img/forum/go_quote.gif so I hear it a lot, and want some good answers based on real tests and so on What will be a better way to connect a DAC to your pc ? A coax or toslink? I am mean connecting it to the digit out of your soundcard what will bring the best audio quality ?

anything less than a 10ft run just use digital coax, but if you're running longer than that or will have said cable run along with poorly shielded cables then you might want to invest in the optical since it's less suceptible to interference

 

[Slaughter]

Quote:

Originally Posted by wavoman /img/forum/go_quote.gif Sending a file does not have a hard real-time requirement. The file transfer methods use error checking and buffering to recover from transmission problems. So do some of the ethernet and WiFi based digital audio transmission methods, but they can't always re-transmit in time before the buffer empties, since you gotta do it before the music stops. Straight digital audio transmission over optical or coax S/PDIF does not have all this logic behind it. Transmission errors can and do occur. Most are inaudible. The file transfer analogy is not a good one. The zeros and ones have to be transferred under a tight time constraint during digital audio transmission, which is not the case during a fie transfer

It's a perfect analogy and you prove it by saying the audio will get to the other end without audible errors, thus proving that there is no difference between coax and optical. Thanks for clearing that up. And in case you didn't know, a transferred file doesn't always recover from transmission errors, thus the need for MD5 when we download large files. So again, they are exactly the same.

 

[philodox]

hohum - I'd try both personally, but would expect Toslink to be superior in that scenario thanks to its immunity from power supply noise.

bigshot - Here is that link I was talking about: CD_transport_DIY

If you read elsewhere on his page you can see some of his tube circuit designs as well as his thoughts on other parts of the audio chain. He is a mild 'believer' in cables, like myself, but seems pretty grounded. I don't follow all of his technical explanations, but what I do understand rings true.

An excerpt:
Quote:

The SP/DIF signal is a 0,5 V pp square wave. It is VERY FAST. it contains 44 kHZ of samples, each sample is a 16 bits, so it is 16 square impulses, and two channels alternating. So we send 2 x 16 = 32 squares per each sample. Plus some other information embedded like end of word, and clock and checksum. So we have roughly 35 squares times 44,1 thousand = 1,543 million pulses per second. From Furrier's theorem we know that the square wave is an infinite sum of sine waves of odd harmonics, so if 1,5 meg is our first fundamental frequency, we need at least 10 harmonics to be represented properly to make a square. This means that we need to send precisely the sine wave bundle which includes clean 1st, 3rd, 5th, 7th, 9th, 11th, 13th 15th and 17th and 19th harmonics. The 19th harmonics of the 1,5 meg is 30 megahertz. That is bloody fast, as fast as radio waves. Contrary to popular belief, the TOSLINK is inferior way of transmission. It has ADDITIONAL transmitter with own electronics and LED light source and corresponding received with light sensor. Its bandwidth is not fast enough to transmit the signal properly. The TOSLINK interface is NOT USING the direct laser!!! It is a cheap interface. It should be avoided whenever possible. AT&T is bloody expensive and not popular even if very fast and accurate. The interface alone costs more than the whole transport. The best way is working on the player to get the signal from the output balancing transformer and add a XLR female socket. The XLR cable can be made of CAT6 LAN cable with twisted pair connected to XLR jewellery of choice. This will transmit the signal in balanced mode isolated from earth and without any cable losses.

I also found this idea interesting, and it does show that there are measurable differences in digital outputs...

CD Transport Digi-Lampizator

 

[upstateguy]

Everybody's an experimenter these days....

Here's what I found:

I bought a Blue Circle "Thingee" to go convert USB to Optical or Coaxial for my Constantine. I'm using a Dayton 18" optical cable, and a Dayton 18' digital coax cable. I also tried a shielded Zu Oxy that I had laying around, to see if there was any difference between the dedicated Dayton coax and a plain shielded cable.

The Constantine has a switch that will send either optical or coax to the DAC. It is very easy to AB back and forth to see which sounds better.

The coax, in all instances, seems to sound ever so slightly cleaner than the optical and that is where I have left the switch.

I can't reliably report there was a difference between the long Zu Oxy and the Short 18" Dayton Digital, but they both were preferred ever so slightly, over the optical.

This is, of course, in my set up, YMMV.

USG


Here is a quick and dirty of the the set up with the Zu cable

 

[bigshot]

I'm afraid I don't understand much on that page. What I do know is that in my A/V rig, I use a toslink cable to connect my macbook with the DAC in my amp. I have never had any problem with resolving of DTS sound- solidly locked on always. I'm assuming that means there are no errors. If there are no errors, toslink can't be any worse than coax. If it does perform differently using a different source or DAC, my guess is that the source or DAC is responsible, not the cable itself. Therefore, there is no inherent difference between toslink and coax. Either one will work. Does that make sense?

See ya
Steve

 

[Pars]

Quote:

Originally Posted by upstateguy /img/forum/go_quote.gif <snip> I can't reliably report there was a difference between the long Zu Oxy and the Short 18" Dayton Digital, but they both were preferred ever so slightly, over the optical.<more snip>

How long is the Zu? The Oxy (fuel) is supposed to be an analog interconnect. Try something 2m or longer and see if you can tell any difference.

 

[upstateguy]

Quote:

Originally Posted by bigshot /img/forum/go_quote.gif I'm afraid I don't understand much on that page. What I do know is that in my A/V rig, I use a toslink cable to connect my macbook with the DAC in my amp. I have never had any problem with resolving of DTS sound- solidly locked on always. I'm assuming that means there are no errors. If there are no errors, toslink can't be any worse than coax. If it does perform differently using a different source or DAC, my guess is that the source or DAC is responsible, not the cable itself. Therefore, there is no inherent difference between toslink and coax. Either one will work. Does that make sense? See ya Steve

Makes sense to me....

But toslink needs 2 extra converters that coax doesn't. At first I thought they sounded the same, but the more I toggled back and forth, coax became the preferred source ....

But I'll tell you what, I'm willing to chalk it up to placebo effect.

USG