What's the difference between all the different audio output sources on DVD players?

[masterc]

this may not be the right place for this question, but it is about DVD players...
I've been looking at buying a DVD player. I've noticed some have Optical and Coaxial audio connections. Some even have a bunch of RCA-type connectors for 5.1 audio out...
I am getting confused. If it says it has DTS or Dolby digital audio output, why are there so many different types of connections??

 

[MazerRackham]

Coaxial and optical digital outs are the same exact thing. No difference but people 'like' the optical one more since it's somewhat cooler.

The 5.1 outs you see on some DVD players are for interfacing with older receivers that don't have built-in Dolby Digital or DTS decoding. I have such a receiver, so I bought a DVD player with 5.1 outs to mate with the 5.1 ins on my Yamaha deck.

If your receiver has either a coaxial or optical digital input (and on-board Dolby Digital/DTS decoding), then you can get pretty much any DVD player you want, since all DVD players should have both a coaxial and optical digital output. Basically anything made within the last year and priced $300 and above should have built in DD/DTS decoding and available digital inputs.

 

[cmdrdredd]

Optical and Coax are used to stream the Dolby or DTS signal to a receiver or decoder. optical is better because there is less signal degredation and better signal over longer distances. The 6channel outputs are for running to a receiver and allowing the DVD player to decode the signal before you get to the receiver.

 

[Goi]

Coaxial and Optical are both digital connections, and may be used for normal PCM digital signal transfers(CD audio) or as an S/PDIF passthrough connection(DD/DTS).
The normal red/white or red/black pair of RCA connectors are for analog stereo, and the 5.1 audio out is either for decoded DD/DTS streams(which means your DVD player decodes DD/DTS rather than your preamp/receiver)or for DVD-A or SACD audio out if your DVD player supports them.

If you're using the digital output, you're bypassing the DACs in your DVD player and using the DACs in your external DAC, preamp or receiver, depending on what you connect it to.

If you're using the analog output, you're doing the d->a conversion in your DVD player and sending an analog signal out, but if your preamp or receiver doesn't support analog bypass, it may be taking that analog signal, converting it back to digital, do some DSP on it(optional) and doing the d->a conversion again before sending the analog signal to your amp. This isn't so ideal due to the number of conversions, which will degrade the signal.

Most people tend to agree that coax digital out sounds better than optical, but a few like cmdrdredd prefer optical. The differences will often be lost in less revealing systems or untrained ears, and it will boil down to a matter of preference.

 

[Eug]

<< Most people tend to agree that coax digital out sounds better than optical, but a few like cmdrdredd prefer optical. The differences will often be lost in less revealing systems or untrained ears, and it will boil down to a matter of preference. >>

Most people tend to agree that coax digital sounds identical to optical. Only the few "golden ears" claim to hear a difference, but it is note this has NEVER been proven in a blinded test. People use the argument of "jitter" introduced by optical connections, but even most engineers agree that for real life usage this is essentially irrelevant.

Eug's assessment of coax vs. optical

1) They sound identical. (My speakers are Paradigm Studio all around, my receivers take both optical and coax, and have had several DVD players, some with optical digital output, some coax, and some both.)
2) Optical is better because the circuit is electrically isolated from the other components, etc.
3) Coaxial is better because you can use $10 cables and have relatively long runs for cheap (and it still sounds fine). It costs a small fortune to get 10 foot long optical cables.
4) They sound identical.

ie. I recommend coaxial not because it sounds better, but because it's less of a hassle and it's a heluvalot cheaper.

 

[Goi]

Eug's, let's not get into that debate...I won't touch it with a 10' pole. Perhaps I should rephrase my previous statement, let's just say that from my experience people tend to prefer coaxial over optical...

 

[masterc]

Thanks for all the feedback ...