Does optical digital out and digital coaxial out make a diff

[Type-E]

It seems that dvd players with digital optical out are generally more expensive, does it really make a difference since both are digital anyway? If Digital optical out does enhance the audio, which DVD player is the best + cheapest w/ digital optical out?

[Psx]

The difference between Digital optical out and coaxial out is negligible really as I have heard they sound exactly the same. As you noted yourself the only major difference however, appears to be the price(with the obvious exception of the cheap HK players that all use the same board which includes optical out).

[thxkid]

Also remember one plays both Digital Dolby and DTS while the other only plays Digital Dolby.
For the life of me I don't remember which one plays both.

[Type-E]

Then I think the optical digital out includes dts. I bought a cheap optical cable from HK Apliu St. for $45 HKD. I believe when it comes to digital, it will either work or do not work, and a cheap cable would not degrade the sound quality, right? I am in the states now, I can't go back to HK to buy a cheap HK player, where in the states has a cheap dvd player that has dts and optical out?

[Greg12]

optical digital out is traveling over fiber optic cable. the signal cannot break down or loose clarity. fiber optics have a bandwith of 10gigabytes a second.

copper wire is 1 meg a second.

<font size=-1>[ This Message was edited by: Greg12 on 2001-08-20 20:53:13 ]</font>

[vitualis]

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On 2001-08-20 20:50:24, Greg12 wrote:
optical digital out is traveling over fiber optic cable. the signal cannot break down or loose clarity. fiber optics have a bandwith of 10gigabytes a second.

copper wire is 1 meg a second.

<font size=-1>[ This Message was edited by: Greg12 on 2001-08-20 20:53:13 ]</font>
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Actually, I believe many people will disagree with you Greg12. We're not talking about internet bandwidth here.

Optic fibre cables (especially cheapo ones) probably introduces more jitter and there is a problem with signal degradation.

There is a reason why there are such wide variations in price for coaxial and fibre optic cables. That reason is probably small, but, for those interested in audio quality and fidelity, important.

Regards.

[Type-E]

I agree that there is a degradation in signal when using cheap optical cable, but if the receiver receives the degraded signal and recognized it and can tolerate it, then there shouldn't be any degradation. Also, we are talking about optical for audio, I think we are not even close to 1/10th of the cable's capability, so a cheap optical wire will do the job properly. Greg12 is some sort of correct, optical wire has a wider bandwidth, but I am sure 5.1 audio channel won't utilize the whole band, and if we are not pushing the wire towards limit, there is no point in buying a really expensive optical wire. The key word is "Digital", it's either work, or don't work, it will no work but degrade the quality.

[flaninacupboard]

hmm, actually thats not true. there will be several error correction processes that occur after the optical signal has been recieved, although, as you're talking about getting the cheapest player you can, this really isnt an issue. incidentally, in the hi-fi community coax connections are considered to be superior, as tranferring the electrical signals to optical ones, picking them up, and converting them back to electrical signals, clearly introduces more possibilty for error.
another factor you may wish to consider, is that some companies (technics is a good example) will only provide optical inputs on their AV recievers, and no coax ones. similarly, some amps have no optical inputs.

[Type-E]

Oh ic, I had a denon receiver and it has 3 optical digital in and only one coaxial digital in

[Type-E]

Wait wait wait, You said coax is better than optical because "as tranferring the electrical signals to optical ones, picking them up, and converting them back to electrical signals, clearly introduces more possibilty for error"????? Does the Coaxial digital signal has to go through the same thing?

[Kdiddy]

to correct above...Coaxial & optical can BOTH provide DD 5.1 & DTS

[flaninacupboard]

well, no it doesn't. it just travels down a wire, instead of all the light conversion jiggery pokery.

[Type-E]

I think the coaxial digital cable and teh subwoofer cable is just another RCA composite cable, it'll work.

[mikldom]

About the Coax Digital Cables...

Yes, regular 'ol rca cables will work, but I would never use one..

I went to walmart and got a digital coax cable for like 6.00.. kinda expensive for that, even for walmart... Really, all it is, is just a Ru-75 coax (used by Cable tv, Satallite, etc), with RCA ends on it.

at Radio shack, I have seen plug adapter thingys that will change the screw on "Cable TV" (or "F&quot end to an RCA end, that way you can use your old cable tv wires...

Think about it this way...

Digital Cable TV uses MPeg2 compression, most Digital Cable TV systems (networks), have like 150-200 channels and then 30 digital music channels too....

COAX (copper) bandwidth is HUGE!!! i don't think that our dvd players piping Dolby Digital (moderately compressed) digital signals or even DTS (lot less compression) will ever take too much of the bandwidth (or capability) of the copper coax digital connection....

I have just a coax digital out on my DVD player (apex), but my Sony Reciever has both optical and coax...

My untrained ear thinks it sounds GREAT.. and the apex pipes regular digital audio out of the coax connection instead of doing and "in-house" digital to analog conversion.. better to let my Nice Sony receiver handle the conversion... and it will pipe the audio digital out from VCD SVCD DVD CDDA and MP3

Just my thoughts to this thread.

Mike

[Type-E]

mikldom, that's what I thought too. I think it's pretty dump to buy really expecial coaxial cable for digital out. As long as the cheap cable is able to deliver the signal and the receiver regonize it, there will be no quality improvement in buying better cables.

ps, I don't think coaxial or optical have different quality on digital audio, it's just different physical layer, anything above that layer is just the same

[patrickm]

as long as the cable has a 75 Ohm impedance (most 'video' cables do, not necessarily all RCA cables intended for audio do) the cabling makes very little difference. it doesn't have to be expensive, just the right electrical specs. you don't even get near exceeding the bandwidth, so 'premium' cable is virtually unnecessary.

as for sound quality of coax vs optical, the concerns audio purists have about jitter are really not all that well founded anymore. it used to be an issue of timing, but recently most components have added a local re-clocking of the signal (similar to a discman's anti-skip buffer) to compensate and correct for jitter. crappy fiber optic cables can be a mixed bag. if they're constructed properly, they're fine, but many do end up with breakages in some fibers, or poor clarity of the ends to transmit the light into and out of the fiber. many expensive cables get around this by simply putting in more fibers, so the less chance for a critical failure. but i'd never recommend anyone spend $80 on a monster cable or something. just make sure what you've got doesn't introduce any noticeable distortions (pops, clicks, etc) and you should be all right.

there may be some truth to the fact that there's more chance for error given an electrical-to- optical-back-to-electrical conversion process, but this is offset by the fact that electrical signals are far more susceptible to EM interference than an optical signal, so assuming your cable goes anywhere near another cable, these two arguments probably offset each other. and as an engineer myself, the more cables it's near, the more i'd lean toward optical when i have the choice.

as mentioned before, both do AC3 and dts. they transmit identical data, just in different forms.

[Type-E]

patrickm, you have explained everything very logically, is there a site or forum that talk about these things? Can you give me the link. This forum is more specialize in mpeg encoding than audio equipments.

[Greg12]

i just thought of something.

are fiber optic light signals subject to electro-magnetic interference.

i know that signals traveling on copper wires can and do degrade faster and sometimes busts of electromagnetic radiation can scramble the signal.

if that's to complicated, imagine turning on a vacum and seeing those lines on the tv.

[species8514]

Coax is far superior to optical becuase of the wider bandwith, which is why you will find only coax used in the best set-ups.

Skywalker sound uses only coax.

Pus someone mentioned you can use any rca cables for a coax connection? This isnt true, most rca cables wont work.

[goober4022]

Optical signals can go for miles without degrading. Copper (home theater copper anyways) can only go about 3 meters before losing signal... And they both can do DTS/DD.

I like optical more than copper, because in most HT setups, not many people know the meaning of "cable management", and have power cords laying across their RCA cords, thus causing some interference. You can get sheilded RCA cords, but it comes up in price to that of an optical cable, so just go that route. (3m optical at best buy is $10(unless you're like me and get name brand all around, then a 3m monster optical is around $30))

Just my $.02

[Type-E]

If coaxial cable does deliver superior quality, then it means that the people who make optical digital out didn't make it right. It has much wider bandwidth yet it didn't deliver equavalent quality