Just my humble opinion that I gathered in over 30yrs+. The implementation of each format dictates the transmission quality/fidelity of each. Having no exposure with FireWire and USB, I canāt comment on those. My personal order of preference is as follows:
- (Provisional) I2S - Had great success with the original mini-I2S ala Audio Alchemy days, specifically Audio Magic cable and still serves as my short cable reference. Itās like no cable at all.
- AT&T ST - Champion of long cables. Iād been using lengths varying from 18ā to 60ā for over 3 decades. It consistently better all other formats Iād tried. (Disclaimer; Didnāt have long enough I2S to compare). One main advantage of using ST cable is total electric isolation between Transport/front end and DAC/back end. Professional recording studio once used this as their universal standard. But again, circuit implementation and cable dressing also plays a very important role.
- AES/EBU - Far from being an exhaustive sample, Iād tried quality cables from XLO, Kimber, Tara Labs, Acoustic Zen, Audio Quest, etc. It is a slight step behind ST for extended length. At the risk of generalization, I found AES/EBUās character to be a touch matter of fact. Great impact but not as flowing and transparent as ST. For years, I had been using a 60ft Canare DA206 110ohm to supplement my long ST with good success.
- S/PDIF - Great performances can be found with cables that strictly adhere to true 75ohm. BNC is the de facto standard and offers the best performance. With few exceptions, phono type connection isnāt true 75ohm and may degrade signal transfer. One should also avoid Coaxial/BNC adopters when possible. My long term favorite is Kimber D-60. Still have a few sprinkled across 4 systems. I recently discovered a fantastic prefabricated cable from Cable Solutions. Iām using a 62ā length Signature Series 77 carrying 24/96 with excellent results. The beauty is in their true 75ohm coaxial connectors. Cost of their 1M is $37.37 and I personally believe that you have to spend up to 10x to equal.
- Toslink - I call them Toss-a-link. Some went as far as disabling their equipmentās Toslink transmitter. So enough said.
Since this is only my personal preference with my specific systems, your finding may and will differ.
Best Regards
Mosler666
PS: My preference between the Canare DA306 and Signature Series 77 is like splitting hair.