Coaxial v. Optical

EndersShadow

Which signal is better and/or why....

If I was planning on using something like a HK 3490 to drive the speakers I know optical passes the signal clean to the receiver. Does coaxial allow you to modify the signal before it gets shipped out or no? I think the HK would have the better EQ but if using a Coaxial connection would allow me to tweak the signal if I needed to at the computer level would that be worth it or am I splitting hairs at this point?

Trying to choose between one of these two soundcards potentially:

Asus Xonar (has optical out Only) or Diamond Xtreme (Coaxial Out only).

The Optical and Coaxial on my motherboard are broke or I would just use that. I have a spare board but dont want to have to tear apart my computer and rebuild it again.

Hopefully this makes sense...urgently need some advice...

messiah

I guess it depends on why you would way to tweak the signal. Personally I prefer optical.

WilliamM2

For connecting to a computer I would use optical. No chance of a ground loop that way. As far as tweaking the signal, that's up to the software that comes with the card, or windows, not the connection type.

WilliamM2

BTW, I'd think about just swapping the motherboard. The one you have seems to be failing, what will quit working next? Only takes a few minutes to swap out a board, if it's the same model.

EndersShadow

WilliamM2 wrote: »

For connecting to a computer I would use optical. No chance of a ground loop that way. As far as tweaking the signal, that's up to the software that comes with the card, or windows, not the connection type.

Ok I was under the impression that optical was a "pure" signal untouched when its send out and that the software would only be used if your using the other connectors on the soundcard.

The Asus card is the one I was leaning toward anyway since the motherboard is also Asus and I like the brand overall.

silvertuner

having the 3490, i personally hear no difference ran either way from the same source (my bluray). if i had to choose, id choose toslink tho i suppose

WilliamM2

EndersShadow wrote: »

Ok I was under the impression that optical was a "pure" signal untouched when its send out and that the software would only be used if your using the other connectors on the soundcard.

That may be, you would have to check with Asus, don't see why coax would be any different though. Either way, you could still twaek the sound with the receiver's controls to some degree.

EndersShadow

WilliamM2 wrote: »

BTW, I'd think about just swapping the motherboard. The one you have seems to be failing, what will quit working next? Only takes a few minutes to swap out a board, if it's the same model.

Nah the headers have been out for over a year and trust me its not that easy in this case. I have spent way to much time doing cable management to want to mess it up again. That and the other board is installed in a partially built server so it would be a big PITA.

Its easier to spend 20 bucks on a cheap soundcard and be done.

ben62670

Opitical has to do 2 extra conversions to get the signal across. Electrical to light and then light to electrical. Another thing is the led in those cheap optical outs don't blink at the speed of light. I choose COAX when I can. Optical and COX are taken from the same source carrying the same exact signal.

zingo

I am currently using optical on my PC source because of the electrical isolation, and I use it on my blu-ray for the same reason. However, I may be switching to coax for my PC as optical only passes 24/96 and I have a number of 24/192 files. :biggrin:

steveinaz

Agree with William, anytime the potential for noise exists, go optical. I did extensive testing (over 6 months) with AES/EBU, Coax, and Toslink links--all of them worked perfectly fine, though with subtle characteristics. AES/EBU (on XLR) had the warmest presentation; Toslink the most neutral. Coax fell somewhere between the two. The test was done with a C.E.C. CD-3300 transport and Benchmark DAC1 (first generation).

heiney9

USB with I2S conversion is the best if you are using a computer. I am in the process of testing this since I just bought a new DAC with USB capabilities. As I understand it I2S protocol means there is no conversion to SPIDF. It also carries the clock info and digital info seperately for the lowest possible jitter.

I do agree that optical is probably better in a computer environment because of possible noise issues. For the main rig I use coax.

H9

EndersShadow

Decision just got much much easier.....

I tested the Coaxial and Optical out on the motherboard header...the Optical is dead....BUT the Coaxial is not...so in order to save some cash right now I think I will be using the exisiting Coaxial connection. Otherwise I would be using a 3.5mm to RCA adapter and the SupremeFX card as that was another option that worked, but I dont think thats a better choice than Coaxial.

I might mess with the chain at a later date by adding a nice DAC that handles USB or Firewire or a better soundcard, but I can at least get started with what I have.

steveinaz

Coax is probably the best, provided you can avoid noise. You get a little of the sweetness of XLR, without the sometimes "boringly" neutral presenation of Toslink--IOW, a little "flavah"

Face

Older DAC's were more prone to jitter and the difference between optical and coax were sometimes obvious. Besides better jitter rejection, some advantages to newer DAC's is I2S as H9 mentioned. Some manufactures now use transformer coupled coax connections, which also electrically isolate the component, so there's no need for optical. Let's not forget asynchronous USB too.

heiney9

http://www.hifi-advice.com/USB-synchronous-asynchronous-info.html

http://archive.anthemav.com/OldSitev1//pdf/i2Srev1.pdf

The above is a very interesting read a white paper.

I2S = Inter-IC Sound
A high speed serial bus standard for use with digital audio and/or video communications developed by Philips in 1986 and based around their I2C chip-to-chip communication standard (aka 12S), were it differs from most such serial systems is that high resolution clocking signal is sent alongside the data itself to ensure synchronisation and reduce or eliminate problems such as Jitter. It was originally designed for on board communications between electronic parts as can be seen from the name and is used as such on everything from high end digital televisions to mobile phones, but has more recently been seen used on high end audio as an external interconnect standard in the form of I2S Enhanced. Basically an IS2 bus consists of 3 signal paths, one has 2 channels of audio or video data multiplexed onto it using TDM, the second channel has clock info and the third is a word select line. Get more info from Philips here (PDF file) or information on the I2s Enhanced here.

jaxwired

Don't know which is best, but what I will say is that digital cables do sound different. Don't ask me why as it does defy logic, but they absolutely do sound different so buy a good cable.

EndersShadow

I will be using a Monoprice cable (already tested it and it works just fine). At some point I might get better IC's for both this system and my Main Rig, but its going to be after I get better speakers as those will be much more noticeable upgrades to my systems...

zingo

A good digital cable is important, but at the bottom of my upgrade list. I am just upgrading mine now from a monoprice optical to a DH Labs digital coax after upgrading and changing out the rest of my system many times over. The only other reason why the digital cable change has been so slow is mine has a 25' run from my PC music server to my DAC...

steveinaz

Look at the Belden 1694A from Blue Jeans, it's cheap and VERY good.