optical VS coaxial

erniejade

I am about to change AVR's and I have a question. On my Onkyo 575 it has 2 coax inputs and 1 optical but the newer receivers seem to have 1-2 coax inputs and 2-4 optical... Is there a sound difference between the 2 inputs?


Just wondering because if it only has 1 then I would have to out my DVD on optical so I can put my cable box on coax input.


Thanks

phuz

Not really, no.

erniejade

Thanks that is what I thought, it would be more on the processing on the receiver or pre correct?

ben62670

Optical adds two more conversions. Coax is better.

phuz

ben62670 wrote: »

Optical adds two more conversions. Coax is better.

Enlighten me, please. How does the "conversion" from electrical impulses to light - and back - effect sound quality?

heiney9

http://www.polkaudio.com/forums/showthread.php?t=75645

http://www.polkaudio.com/forums/showthread.php?t=36415

http://www.polkaudio.com/forums/showthread.php?t=29489

http://www.polkaudio.com/forums/showthread.php?t=17990

http://www.polkaudio.com/forums/showthread.php?t=2661

Found these 5 links in mere seconds. Should answer any questions you have

H9

ben62670

It's fine if you believe that optical is better. Why would more conversions be better? Optical is coax converted to optical and back to coax on the receiving end.

phuz

ben62670 wrote: »

It's fine if you believe that optical is better. Why would more conversions be better? Optical is coax converted to optical and back to coax on the receiving end.

I never said either was better.

I'm just curious how the 0's and 1's are altered by the "conversion" to or from light. The signal is digital all the way through both types of cables, so I'm curious how one digital transmission is better than the other.

erniejade

Thanks for the links!!!!!! Since the cable box is well... You cannot get the same sound out of it as you can a DVD or BRP,,,, i think the coax will go with the dvd and optical the cable box.

that should work!

I was going to get the onkyo fixed but, as crazy as it sounds, I can get another used unit cheaper!!!! This system is for movies and cable only... Be nice to get the Velodyne spl1500 going again lol. The receiver blew a channel out about 4-6 months ago. Wanted to play catch up on moves so I started looking on craigslist.

yepimonfire

optical is much more buggy and unstable then coax, im not even sure why they implemented it into AVRs ..... but the thing about digital is it either works correctly or doesent, there is no difference in sound quality no matter what cable you use to transmit the data as long as it is the same format.

nguyendot

One word:

jitter.

more prevalent on optical.

With our level of equipment, you won't be able to tell, unless you listen with an oscilloscope.

yepimonfire

ive never been able to figure out, WHAT IS JITTER?!?!

heiney9

yepimonfire wrote: »

WHAT IS JITTER?!?!

It's what happens when you don't have your coffee in the morning

http://www.jitter.de/english/engc_navfr.html

Get your read on. Look to the left after you link the page for a break down and explaination of Jitter. It's a serious phenomenon and the link above is a serious and well laid explaination. Those with short attention spans need not click on the link

H9

mantis

There is no difference in sound quality . It's exactly the same. Digital is digital . As long as the cable can transfer the signal without losing anything it's exactly the same.

I'll challenge anyone with any cable to hear a difference. I have been down this road many years ago with many people in blind tests and not a single person could tell any difference.

heiney9

Jitter is real and it can be introduced via cables among other things.

danger boy

I betcha most of us could not detect jitter in a home theater. maybe in 2 ch music, but home theater, pretty unlikely.

don't worry about jitter, it'll just make you jittery.

Conradicles

danger boy wrote: »

don't worry about jitter, it'll just make you jittery.

hehe...I like that quote!:cool:

mantis

heiney9 wrote: »

Jitter is real and it can be introduced via cables among other things.

Agreed in poor quality cables. Once you have a quality Optical cable that can pass the full signal this is a non issue.

comfortablycurt

I've never experienced any differences between optical or coax cables.

For that matter, I've also never heard any differences between different optical cables...with the exception of a "spaghetti noodle" coax cable that came with an old Sony HTIB. I found some big improvements by upgrading that coax cable...but that was probably more due to having better shielding etc.

falconcry72

I've never heard a difference, but optical cables can brake easier.

weitrhino

Optical will allow you to maintain electrical isolation between the two devices you're connecting which could be used to eliminate a hum issue. But as I understand it, coax digital theoretically has more bandwidth availability.

mantis

weitrhino wrote: »

Optical will allow you to maintain electrical isolation between the two devices you're connecting which could be used to eliminate a hum issue. But as I understand it, coax digital theoretically has more bandwidth availability.

The only concern here despite which one has more bandwidth is can the given cable pass the entire signal? If so it can have all the bandwidth , gold plating , cool looking connectors what ever , you can't improve on what already is. I like Coax over Optical only as optical can be broken much easier. I can build custom length Coax cables that perform 100%. I don't build fiber cables , kinda wish I did.

As far as the isolation , I have done this countless times in the past . I try to use them mostly on cable boxes so there is no metallic connection between the receiver and cable box. I'm going back a few years.

Serendipity

I can't hear a significant difference between the two.

PerfectCreature

I don't really notice a difference either. I did notice that if you have the optical hooked up to one end but not the other that a red light goes through it pretty nifty.

digitalvideo

From what I heard over the years audiophiles prefer coaxial to optical, and typically use a digital connection to a pre-pro for music playback (rather than HDMI audio, which most use only with video sources).

doctorcilantro

This sums up what I often hear about Toslink conversion from voltage to light:

All digital audio signals are initially voltage pulses essentially identical to the signals placed on the coax connections. To get the optical audio signal those voltage pulses are applied to LED (light emitting diode) devices (called Toslink transmitters) to convert them to pulses of light for transmission through optical fiber cable to a Toslink receiver at the other end where they are converted back to voltage pulses. That conversion to light pulses and back to voltage introduces slight offsets in time as the light emitting diode transmitters and photo detector receivers can not respond instantaneously. Those slight offsets make no difference as long as the packets get through the specs (and they are if you hear the audio) but my point is that a coax signal of that same digital audio won't have those distortions or offsets (which some call jitter if it varies over time). So, technically, coax digital audio signals should be "better" than optical - not the other way around.

http://www.lipfix.com/lipfix_faq.html

Personally, I have found Toslink okay, but mechanically unreliable; loss of sync of you bump a cable reaching for another component etc.