Which is better Coax or Optical cables

I have always preferred Digital Coax, but must admit that the new DH Labs Glass Master Toslink does indeed sound more analog with no loss in resolution.  The people on this board touting Glass Optical Cables are correct.

Most of my listening in recent years has been via a solid desktop audio system, which I've repeatedly upgraded over the past 2 years. In that time I used 4 different DACs, with signal coming from a 24/96 Musical Fidelity S/PDIF converter, which I upgraded to the 24/192 M.F. unit ~9 months ago. On all 4 DACs I compared USB to coax; on 2 of the 4, I compared also USB & coax to toslink/glass.

Here's what I heard:

1 - Coax sounded better to me with all 4 DACs. The difference was not particularly large: but was certainly audible.

2 - In all cases, coax sounded more relaxed, a bit less edgy/glassy--a more expansive, enjoyable sound vs USB and toslink/glass.

3 - In all cases, I heard these differences both through speakers and  headphones (4 different headphones).

The problem with coax (the opportunity, as well) is there are so many brands, designs & differing costs. No one can listen to all the coax cables that get mentioned/praised in reviews and forums. I began  with an inexpensive Billy Jeans 1.5M coax, which I preferred to USB (Belkin Gold) or SonicWave "Impact" toslink/glass.

Then, based on favorable reviews from sources I trust, I upgraded to a 1.3M cable by Oyaide (DR-510), ~$220 shipped direct from Japan. It immediately sounded better than the BJs in every way--again, rather subtle but welcome differences.

My current DAC is IMO endgame-quality: Audio GD NOS 19 (an R2 R, non-oversampling design). It's 5 months old & has the latest Amanero USB implementation. This is a very fine sounding unit, and the Oyaide coax pushed it even further in the direction of relaxed (yet more than sufficiently detailed), analogue-like sound.

I will soon replace the M.F. 24/192 converter with the Singxer SU-1, which has been very favorably reviewed in multiple publications & platforms. I will revisit the USB vs coax vs glass with the SU-1.

Pls note that in all cases, the USB signal is conveyed via a USB Regen device.

I have the Oyaide but the Transparent is better but more money. I had one and sold it but missed it so much I bought another. Big sound  difference between brands.

I have the Tellurium Q Black Digital coax cable, astonishing sound : natural ,transparent and spacious soundstage.
The downside, it’s a revealing cable that immediately will expose bad recordings and weaknesses in your system.
After buying it I noticed that my power amp and CD weren't good enough and upgraded both also many bad recordings can't be heard anymore especially those made at the 80's unfortunately. But good cable should be faithful and revealing ...

Use Coax never optical unless absolutely necessary. Just think about whats happening to the digital signal and conversion losses, it matters... 

Caution: The optical inputs are not recommended for DSD or for sample rates above 96 kHz. Optical connections may be unreliable at sample rates above 96 kHz.