Digital inputs ....is one really better than another?


My current digital system is a Bryston BDP-1/BDA-1 combo connected via AES/EBU. My plan is to upgrade at least the DAC in the very near future. I noticed that most higher end DACS don’t have AES/EBU inputs. Is it because the AES/EBU is inferior in SQ? If this is the case, I want my replacement DAC to have AES/EBU for use with my current player and the preferred input for a future player upgrade.  
rockyboy

No, AES/EBU is eliminated from many designs because of the cost savings and panel or board savings, or maybe because it’s a more squirrely interface, or maybe the designer does not know how to implement it.

It is squirrely because the XLR connector is not designed for a good termination to 110 ohm cables and the connector itself is not 110 ohms characteristic impedance.

It’s much easier and less expensive to design and implement a high-performance 75 ohm S/PDIF cable than a high-performance 110 ohm AES/EBU cable.  The cabling or circuit board inside the DAC and Transport are also a consideration.  These are more easily made 75 ohms than 110 ohms.

Steve N.

Empirical Audio

In the case of the Schiit Yggdrasil, AES/EBU input is preferable over S/PDIF. Mike Moffatt says so.
Bryston rep claims AES/EBU is best for BDP-1/BDA-1; but USB connection is best with the BDP-3/BDA-3. I wanted to upgrade to an Aurender player but the Aurender lacks AES/EBU; and Bryston told me SQ would suffer using the BDA-1’s USB. So my path forward appears to be either 1) keep the Bryston player and upgrade DAC to one with AES/EBU or 2) upgrade both units with ones having USB inputs. Right now i’m looking at buying a Lampizator DAC with AES/EBU. 
Rockyboy, If I were considering a DAC upgrade over my BDA-1, I would also be considering the Lampizator line of DACS. I have heard elsewhere that the AES/EBU interface is superior. I but would like to add that I use a Audiophileo2 connected to my BDA-1 via AES/EBU directly without cable. I believe I heard on another forum that using a cable is better however I have not tried that. Wonder if the recommendation of use of cable is due to the 110ohm  requirement.
Steve, are you saying that AES/EBU, when done right, is the best connection?
Mesch, you say your Audiophleo2 is “connected via AES/EBU directly without cable”.  Huh? How is that accomplished?

Steve, are you saying that AES/EBU, when done right, is the best connection?

There are positives and negatives with AES/EBU.

Positives:

1) some common-mode noise rejection - this can be accomplished with S/PDIF with a pulse transformer and it’s even better rejection.

2) edge-rates don’t have to be as fast as S/PDIF

Negatives:

1) usually requires a higher voltage than S/PDIF and an additional driver, which adds jitter

2) more difficult to make a good cable because of the connectors and twinaxial construction

3) edges must be consistent, rising and falling and with different timings, a difficult thing to accomplish

The bottom line for me is that if you know how to do S/PDIF correctly, it is the interface that will deliver lower jitter. And here we get to the reason why some manufacturers are preferring AES/UBU:

1) they don't understand how to make a fast S/PDIF interface

2) they don't understand how to match the 75 ohm impedance

I have modded enough different transports to know that these are the facts.

Steve N.

Empirical Audio


OP, nothing for nothing as I've been reading the thread now since its inception and remained on the sidelines... Steve (audioengr) is unquestionably extremely knowledgeable, and (as I always do) should be thanked repeatedly for imparting his knowledge (and even going further to present measurements as evidence).

But in my experience and to my ears, and I implore you to do the same if you can and if practical in this case is "use your ears and then examine what your brain tells you". 

To share what I've discovered, despite whatever measurements the naysayers will produce, is that AES/EBU bests S/PDIF, and S/PDIF bests USB. Simple as that.
I appreciate everyone’s input. I lack local audio stores and can’t afford to ship in equipment to audition. And I suspect I have only a single upgrade in my future before “the wife” puts her foot down. So that’s why I’m asking questions. I’ve followed Steve on this forum for years and the man knows his stuff but he’s way over my head with his knowledge. I’m a plug and play guy. The technical aspects just give me a headache. That said, think I’ll pursue a Lampizator DAC with AES/EBU and maybe upgrade to a Bryston BDA-2......and then find contentment  with my system . 
The Audiophileo2 has a AES/EBU output that attaches directly to the BDA-1 AES/EBU input. Also comes with adapter that allows connection to RCA coax.