Are there differing qualities of optical cable?


I currently have my Gungnir Multibit DAC connected by optical cable to my Oppo player which I use as a transport. I also have a Cardas coax cable connected to a different input.  The optical sounds better. My question is, are there different qualities of optical cable you can use, or is one the same as the other?
7c67ab18 c2ce 4b45 9523 fc4a71684ce0rvpiano
There are differing qualities of optical cable, yes. Glass cables are generally better than plastic cables (almost always true). ST optical connections are better than Toslink optical connections. (almost always true)

Coaxial RCA cables for digital are almost always better sounding than any optical cable. For audio (A Caveat).  As in-I've never heard a optical cable outperform a coaxial connection.

the right inexpensive coaxial cable can sound better than some expensive ones.  Try a few, even some well built cheap ones.

Your experience with the optical cable seems to be saying that something is likely amiss, as George is no dummy. His coaxial cable will be well built and sound good.

Your situation may be exactly true and right but it would be very much against the odds that the record of experience indicates as what is likely to happen..

How long is the Cardas COAX?  If it's too short, you could be experiencing signal reflections back to the spdif transmitter.  I have also experienced differences in quality of toslink cables.  The cheaper ones will have a single plastic mono-filament.  The better ones will have a high count glass fiber medium.  Look at the Lifatec cable, or the upper end Wire World cable.

For the COAX, try a 6 foot Blue Jeans cable Beldon 1694A.  Or move up to something like a DH Labs D-750 cable.

@rvpianos 

To add to what teo_audio has stated regarding coax, I am using coax from my Oppo to Yggy. In fact, Schiit recommends coax (over optical). I asked :)

That said, all of my cables are from https://www.bluejeanscable.com/
It shouldn't sound different unless the DAC is not handling jitter very well in which case you may need to experiment to find out what works best in your situation.

I assume you are playing CDs which should be fine. Just avoid using this DAC for any higher than 18 bit files as it probably just truncates and throws out the least significant bits on any digital music above 18 bit.
Since the consensus seems to be that coax is better than optical, I ordered the DH Labs D-750 coax cable.
Hopefully it will do an even better job than my Monster optical cable, which is sounding quite good right now.
The Oppo does use a switching power supply for the digital board. Some of this switching noise could be making it into that COAX (if you are using the Oppo as a Transport). The toslink fiber cable electrically disconnects the DAC from the transport, so it could be insulating your Gungir DAC from that switching power supply noise. Just a theory.
rvpiano
My question is, are there different qualities of optical cable you can use, or is one the same as the other?
Yes the polished optical glass cable is the best (can’t bend it too much), Wadia had these as an ST type connection with an AT&T reciever (not Toslink), with a small smear of what called "optical indexing fluid" on the ends and then plugged in. The fluid was very expensive and optically clear, it gave a far better coupling between the end of the glass fibre and the receiver lens. Would work with Toslink as well I would think.
https://www.newport.com/f/index-matching-fluid

https://www.ebay.com.au/sch/i.html?_odkw=ST+optical&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.XST+optical+cable.TRS0&_nkw=ST+optical+cable&_sacat=0

Cheers George
I installed a new glass fiber optical cable.  It was a definite improvement over my previous Monster optical.
Today I just got a new DH Labs Silver Sonic coax cable.
Again, a definite improvement over my previous Cardas coax AND definitely better than the new optical.
So, double improvement!
Thanks for all the suggestions.

Question:  Does coax cable require burn in?
It sounds great right now.
Awsome that you had a significant improvement! I suspect that some burn-in will help.  I don't think it will be as drastic as an analog cable.
And there are people that say cables don’t make a difference!
Thanks Auxinput for your awesome suggestion.
i can’t believe the difference.
The cable removed distortion I had in a very, very loud Mahler symphony (#8) and significantly improved sound staging.
After reading the above blog, I can only assume my observations are delusional.
After all, how can the ear of a musician match the accuracy of scientific instruments?
I’ll return the cables immediately!

Yep, willemj has been a strong proponent of publishing measurements that are supposed to indicate the be-all-end-all of audio quality. After 17+ years of listening in this hobby, I do not agree with him at all.

The following link was found by another poster when he was trying to find some documentation after I told him that toslink was not as good of a interface as digital coax.

http://www.lampizator.eu/LAMPIZATOR/TRANSPORT/CD_transport_DIY.html

When you read through and get to the measurements of the toslink interface, I thought it was really interesting how bad the toslink waveform was. You would assume that light transmission would be better than electrical transmission, but in truth the LED light emitting diode just cannot "light up" fast enough to keep the true square waveform.

It also shows that not all SPDIF outputs are created equal. lol.


First, about methodology. Yes, a modern audioanalyzer like a DScope or Audio Precision is indeeed more discerning than even the best human hearing. They can measure subtleties that no human can hear because they are beyond the threshold of human hearing acuity. Think of the parallel with microscopes or telescopes.
As for interfaces and cables, this discussion was about the cables, not the respective merits of the interfaces. If you compare digital interfaces, usb is best for jitter, distortion and noise, followed by coaxial and just after that optical. Do these differences matter? I doubt it, as they are at such elevated levels that no human is likely to hear them (under controlled conditions, of course).
@willemj

The interface is indeed the issue and it depends on the methodology of implementation.

I would argue that USB digital has been a disaster for many years.

Even today day I think the approach can be worse than Coax or Toslink because of logic induced modulation noise induced back into the power supply of the USB DAC.

Does it matter - absolutely! Non random Jitter is quite audible even at picosecond levels. Check out Cranesong website for some jitter demonstrations.
Willemj:

So you evidently believe that the differences I, and others hear, is imaginary.
The objective listening of listeners to various cables is real.
Obviously the testing instruments are not capable of picking up the kinds of differences people hear.
These tests are useless and hence, worthless!
Blind faith in current scientific methodology leaves no room for discovery.
Blind faith in current scientific methodology leaves no room for discovery.

And Blind Faith Live in Hyde Park June 7, 1969 SBD London, England is definitely worth listening too :)


@rvpiano  Any reason why you didn't try the DH Labs Glass Master Toslink? Might have been an interesting comparison between house cables (vs. your DH Labs Silver Sonic coax cable).
I got the glass cable before I heard of DH Labs or I would have.
(Still can I guess.)
I'm using one for the digital audio out from my tv to my DAC. 

My previous one was from Monoprice and the DH Labs outperformed it.

I haven't done any comparisons between different brands or in your case: what I was hoping, i.e. the same brand but different digital cable types.

Digital cables or Toslink do add jitter, so getting good ones will help. Add as little as possible.

I also thought that the best glass cable was the ticket, until I discovered a really outstanding plastic cable. I even use a 15-footer of this from my Smart TV to my SS processor:

https://btpa.com/TOSLINK-XXX.html

Steve N.

Empirical Audio

Whatever type of optical you use, try a drop of the "indexing gel" with it as it couples the optical fibre end to the internal receiver minimising any refection, thus reducing jitter.

https://www.newport.com/f/index-matching-fluid

Cheers George 
Jitter is not additive if you have a properly designed asynchronous DAC.

Again it is the equipment design and build which is key and not the cable. Incoming jitter becomes irrelevant if you have a DAC that ignores it.
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