jazznut said I just try to sum up my insight from Ted's useful info:Just because I'm a pedantic kind of guy and abhor oversimplifications:Toslink can do from 96-176k, has higher niose and lower ground loop risk
Coax can do up to 192k or 1xDSD, has lower noise and higher groud loop risk
USB can do any samplerate, has higher noise and higher groud loop risk
I2S can do up to 352k or 2xDSD, has lower noise and lower ground loop risk, but designed for short lenghtsI also got, that in general USB and Toslink are considered as the worst options (except for USB’s ability to do all sampling rates) while Coax and I2S can be the best solution for limited sampling rates depending on the rest of the equipment.
And I got, that going by LAN or WLAN into the Bridge has less risks of noise or ground loop than using any direct input into the DAC by any other option (USB. i2s, Tos, Coax) and is probably the best sounding solution, independent of possible noise from a NAS, too.
Correct?
The term “Noise” isn’t being used consistently in this synopsis - for example TOSLink typically has the lowest electrical noise but somewhat higher jitter than AES/EBU, S/PDIF and I2S.
Because jitter is less of a problem for the DS the common knowledge about these formats isn’t entirely true for the DS, in particular I use TOSLink instead of S/PDIF or AES/EBU when 24/192 TOSLink is reliable in my system. (In fact I did all of my demos of my prototype hardware with a cobbled PC → USB → S/PDIF → TOSLink → DAC signal chain.)
Also with the DS if all other things are equal (e.g. from the same source/hardware to the DS) I2S, AES/EBU and S/PDIF have very similar performance - If a reliable TOSLink connection isn’t available and all other things are equal I would use I2S for short connections because it typically has robust shielding and good grounding, for longer connections I’d use AES/EBU for the better common mode rejection and wider compatibility - but any of them can work well.
The Bridge isn’t inherently a lower noise solution than others (and certainly not lower noise than TOSLink). Like all of this the Bridge’s benefits are quite system dependent but for many people the bridge provides excellent sound quality. With a NAS in the same room as the rest of my system the Bridge was the noisiest (in more than one way) and worst sounding connection - but with the NAS in another room and plugged into a remote outlet the Bridge sounded much better.
So, just to beat a dead horse, all of these things are system specific and you can get great sound quality with any of them - personally I choose the one that best matches my lifestyle / system layout / user interface / available sources concerns and then tweak it to work as best I can up to my frustration and budget thresholds.