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?
128x128rvpiano
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).