AES/EBU....

[jky999]

Is AES/EBU a preferred digital transmission from source to DAC compared to rca?

 

Thanks for any help.

 

[Audio_ELF]

And you'll get a dozen answers...

 

Some say AES3 (via XLR) is great, others say the only reason for the standard being via XLR is the abundance of (mechanically) suitable cables in studios, etc.

 

BNC is generally considered superior to Phono for digital signal as it's a true 75ohm connector.

 

Eloise

 

[Bob Stern]

Coax cables with BNC connectors would appear to be the best, since RCA and XLR connectors are not designed to have a predictable impedance at RF frequencies.

 

However, when I tested different computer interfaces for my Bryston DAC, I found using a borrowed Sonic Studio 4 as a firewire-to-AES converter worked better than the alternatives described in my earlier post. The Sonic Studio 4 provides AES output only at a DB-25 connector, which I doubt has a specified RF impedance. The cable assembly I used had an Amphenol DB-25 connector on one end, 4 Neutrik XLR's at the other end, and 4 Mogami cables (I did not note the type).

 

My guess is that the connector is so small relative to the wavelength that good impedance matching is accomplished by proper resistive termination inside the hardware on each end and a cable with proper characteristic impedance, regardless of the connector's characteristic impedance.

 

[cfmsp]

 

"others say the only reason for the standard being via XLR is the abundance of (mechanically) suitable cables in studios, etc. "

 

If true, it's yet another example of ubiquity winning out over performance. I would argue that's also the case with USB's dominance over Firewire. I've found not a single shred of compelling evidence (to me as a consumer) to support use of USB over Firewire, other than the sheer number of USB devices.

 

clay

 

[bordin]

I had a discussion with a friend of mine. He doesn't understand why the AES Committee endorsed the XLR wiring for a digital audio transmission standard. It is really bad for high frequency application, due to noise, particularly at the connectors.

 

The best cabling is coaxial with BNC connectors which has the highest noise immunity.

 

Perhaps, there were surplus inventory of analog XLR parts, in every studio. ;-)