Any difference (in sound) between Optical and Coxial connection?

[wshtb]

I am running a coxial cable (generic speaker cable with RCA connector on both end) from SPDIF output of my Audigy to my receiver. I always wonder will there be any difference if I spend another $50 to get the optical addon card?

I have some thoughts on this problem.....
1. Optical connection suffers virtually no interference from environment, so it SHOULD give better sound.
2. But the signal are in DIGITAL format, so the interference on the coxial cable doesn't matter...

Am I right? Is there anyone who have experienced both? Can I share your experience?

Thanks!

 

[John]

A "digital coaxial" cable from 2 audio/video devices should be a 75ohm cable w/ copper center conductor & rca style connectors. You also see RG6 style coaxial cables in your house with F style connectors. Most people prefer the digital coax to the toslink (fiber optic), but the sound is debatable depending on your ears and the equipment used.

 

[RemyCanad]

I would say the optical is overkill unless you have some really nice speakers and such.

 

[Workin']

There is NO difference in the sound unless you are operating in an area of HEAVY electrical interference, and even then there may be no difference.

I think that unless you happen to be running a large Tesla coil in the same room you should be fine with coaxial.

 

[Goi]

Oh my, put your flamesuits on...

Basically, most would say that there's no difference in sound, according to the argument that "digital is digital". Well, there are differences, but generally they're not very audible to most people so you should be fine with either. Those who can tell the difference generally prefer the coaxial connection, which makes the optical connection pretty redundant. In fact if you look at most high end audio components they often only have a digital coaxial jack and no optical one.

 

[flood]

Originally posted by: Goi
Oh my, put your flamesuits on...

Basically, most would say that there's no difference in sound, according to the argument that "digital is digital". Well, there are differences, but generally they're not very audible to most people so you should be fine with either. Those who can tell the difference generally prefer the coaxial connection, which makes the optical connection pretty redundant. In fact if you look at most high end audio components they often only have a digital coaxial jack and no optical one.

I recall reading a test done with all dolby equipment showing that the bitstream through TOSlink, coax, and a meta coat hanger (yes, used as a coax cable) had a 0% error rate.
The guy used a unit mady by Dolby to detect errors in a bitstream. I'll see if I can find it... its got pictures and all.

 

[Goi]

Well then go ahead, use a coat hangar. 🙂
Suffice to say that the differences in the signal don't manifest themselves as pure data errors.

 

[Workin']

Suffice to say that the differences in the signal don't manifest themselves as pure data errors.

Sorry to be ignorant, but could you please elaborate on what, EXACTLY, could make a difference in the sound of a digital bitstream as carried by a piece of wire vs. a piece of glass? It's ones and zeros, nothing else, no distortion, no harmonics, nothing else.... If 1101011010101101 goes into one end and comes out the other as 1101011010101101 (i.e., no data errors), please explain how it could possibly sound any different using the same A/D/A converters?

I'm not meaning to flame you, or start an argument, I'm just waiting to be enlightened. Please tell us how this could be possible.

 

[Chad]

I know interference can make a very distinct high pitched whining noise. Sometimes you can even hear it straight from the wires themselves. Maybe that's what he means. The coax I guess could be subject to interference. And no, a Tesla coils is not needed... my home entertainment center has so many wires and crap all hokked up that just by sticking your head behind it you can here all the interference.

 

[Pariah]

"please explain how it could possibly sound any different using the same A/D/A converters?"

There are still various anomalies that can occur during the transfer of digital audio. Timing errors like jitter being the main culprit. There is a good article on it here:

EVERYTHING YOU ALWAYS WANTED TO KNOW ABOUT JITTER BUT WERE AFRAID TO ASK

"High jitter may result in clicks or glitches as the circuit cuts in and out"
"A typical D to A converter derives its system clock (the clock that controls the sample and hold circuit) from the incoming digital signal. If that clock is not stable, then the conversions from digital to analog will not occur at the correct moments in time. The audible effect of this jitter is a possible loss of low level resolution caused by added noise, spurious (phantom) tones, or distortion added to the signal."

It's the same problem you get with ripping audio CD's. It's a straight digital read and transfer so the copy should be perfect, correct? Well, we all know that isn't always the case and certain cdrom drives add pops and clicks to the audio along with other distortion despite the fact it is supposed to be a pure digital transfer. TOS links are less susceptible to outside interference which should result in more accurate transfers, though the difference is unlikely to be noticable to the layman who isn't using top of the line equipment.

 

[bigboxes]

Originally posted by: Goi
Oh my, put your flamesuits on...

Basically, most would say that there's no difference in sound, according to the argument that "digital is digital". Well, there are differences, but generally they're not very audible to most people so you should be fine with either. Those who can tell the difference generally prefer the coaxial connection, which makes the optical connection pretty redundant. In fact if you look at most high end audio components they often only have a digital coaxial jack and no optical one.

Well, my Denon receiver has 3 optical inputs and no digital coaxial inputs.

 

[Magicthyse]

Originally posted by: bigboxes

Originally posted by: Goi
Oh my, put your flamesuits on...

Basically, most would say that there's no difference in sound, according to the argument that "digital is digital". Well, there are differences, but generally they're not very audible to most people so you should be fine with either. Those who can tell the difference generally prefer the coaxial connection, which makes the optical connection pretty redundant. In fact if you look at most high end audio components they often only have a digital coaxial jack and no optical one.

Well, my Denon receiver has 3 optical inputs and no digital coaxial inputs.

high end, he said, not some 5.1 consumer thingummy.
Mind you, even the CEC transports have optical, coax and xlr...

 

[Auric]

Yeah, that's kinda backwards. Low-end gear forgoes the optical. Sans inteference both will be the same. The electrical connection obviously has more potential for interference.

Optical outputs can be had for $12. You do not have to get the overpriced and often under-featured Creative ones.

 

[bigboxes]

I didn't realize that my Denon was lo-end. Thanks for the education. I highly doubt that you will find my Denon model at Wal-mart, but thanks for playing... maybe you are thinking that it has to be separate components to be considered hi-end (amp, pre-amp, tuner). If so, Magicthyse, you are an audiophile snob. 🙂

Maybe you are thinking ultra high-end. As for me, with my Denon's 7.1 channels, massive power supplies and low distortion, I don't think I could turn it up loud enough to hear that distortion without going deaf or enjoying a visit from the police (courtesy of my neighbors). 😉

 

[Magicthyse]

Originally posted by: Auric
Yeah, that's kinda backwards. Low-end gear forgoes the optical. Sans inteference both will be the same. The electrical connection obviously has more potential for interference.

Optical outputs can be had for $12. You do not have to get the overpriced and often under-featured Creative ones.

You know the wierd thing? I had to buy a separate CD player with optical out to record stuff onto my minidisc. My main CD player doesn't have optical sockets. Or a headphone socket. Or RCA sockets...

 

[John]

Originally posted by: bigboxes
I didn't realize that my Denon was lo-end. Thanks for the education. I highly doubt that you will find my Denon model at Wal-mart, but thanks for playing... maybe you are thinking that it has to be separate components to be considered hi-end (amp, pre-amp, tuner). If so, Magicthyse, you are an audiophile snob. 🙂

Maybe you are thinking ultra high-end. As for me, with my Denon's 7.1 channels, massive power supplies and low distortion, I don't think I could turn it up loud enough to hear that distortion without going deaf or enjoying a visit from the police (courtesy of my neighbors). 😉

So as long as Wal-Mart doesn't carry a particular home theater receiver it should be considered high-end? 😉 What model is your Denon receiver? I have the 3802 and it comes with a digital coax + several toslinks.

 

[wshtb]

From above informations, can I say if you are using a receiver, then the D/A converter on your sound card DOESN'T matter at all? The true 16-bits faked 24-bits D/A convertion on the audigy is useless if you you are running digital cables between sound card and receiver, right?

So the lowest end sound card with optical output will just work ABSOLUTELY no difference with the highest end sound card (not audigy) if using SPDIF/OPTICAL connection to a receiver?

I start to regret buying this audigy...... I can get a pretty damn cheap optical output sound card....

By the way, I don't play game, on that Audigy X-Gamer...

 

[Workin']

So pariah, are you saying that coaxial is more prone to jitter than optical (or vice versa)? If anything I would say that optical is more prone to jitter errors since the digital signal has to be converted from an electrical to an optical and then back to electrical signal.

From above informations, can I say if you are using a receiver, then the D/A converter on your sound card DOESN'T matter at all? The true 16-bits faked 24-bits D/A convertion on the audigy is useless if you you are running digital cables between sound card and receiver, right?

Right. The digital output bypasses the D/A converter.

So the lowest end sound card with optical output will just work ABSOLUTELY no difference with the highest end sound card (not audigy) if using SPDIF/OPTICAL connection to a receiver?

Theoretically, yes. In practice, probably not - because of added noise or excess jitter. But most people on most days couldn't tell the difference.

 

[bigboxes]

What model is your Denon receiver? I have the 3802 and it comes with a digital coax + several toslinks.

lol... My bad. 🙂 I have the AVR3802 as well. It has one coaxial digital input as well as three (3) optical inputs. I'm still laughing John!

 

[Pariah]

"So pariah, are you saying that coaxial is more prone to jitter than optical (or vice versa)?"

No, you asked how a digital audio signal could be altered, and I gave you your answer.

 

[Goi]

Oh well, guess the can of worms was opened anyway. Anyway, what I was talking about has already been mentioned by Pariah - its called Jitter. The link he provided should be interesting and informative for anyone who wants to know more. Jitter is more apparent on optical connections using the TOSLink connector than coaxial(RG59 or RG6) connections using RCA/XLR connectors. Its an inherent flaw of the TOSLink connector. There's nothing really wrong about optical cables, however Toshiba had to go and come up with the POS lossy TOSLink connector, that's right, the TOSLink connector loses at least 0.5dB, even though the actual loss in the fibre is something like 0.3dB/km. Also keep in mind that you have to modulate your basband digital signal and then demodulate it when you go through the glass/plastic optical cable. With a coaxial cable, you don't have to do any modulation/demodulation.

bigboxes, not to rip on your system or anything, but the Denon AVR-3802 is hardly high end. Its definitely very decent for its price, and is quite frankly IMO just about unbeatable in its price range, but its still entry level to mid-range equipment. You really have to start diving into separates before you hit high end.

regards

 

[kgraeme]

Actually, I've noticed a HUGE difference in sound between the two. With a Coaxial, I always here the sounds of rotting meat with plenty of flies and lots of green garbage bags. With an optical connection, it has the quality of a glass filled with 10w-30 motor oil as it slides down a hand polished wooden bar.

Seriously, I don't think it matters too much. I remember when these connectors were just being introduced that there was a lot of argument. People generally felt that the coax had a little richer, warmer, more natural feel to it. Another point of contention was the relative fragility of optical cable. Note the word "relative". Like I said, I don't think it matters too much.

 

[Workin']

Toshiba had to go and come up with the POS lossy TOSLink connector, that's right, the TOSLink connector loses at least 0.5dB, even though the actual loss in the fibre is something like 0.3dB/km.

EVERY connector in ANY fiber optic system introduces a fraction of a dB loss - it's not like it's Toshiba's fault, and it's not like the level of the reproduced analog signal is affected. It's just something the designer of the de/modulator has to take into account when selecting the LED launch power.