Coax to BNC connection for digital

Actually some equipment provides an AES/EBU interface on a BNC connector, with a 75 ohm impedance!

From this Wikipedia writeup:

AES/EBU can also be run using unbalanced BNC connectors with a 75-ohm coaxial cable. The unbalanced version has a maximum transmission distance of 1000 meters as opposed to the 100 meters maximum for the balanced version. The AES-3id standard defines a 75-ohm BNC electrical variant of AES3. This uses the same cabling, patching and infrastructure as analogue or digital video, and is thus common in the broadcast industry.

Best regards,
-- Al

Well thanks again Al!  I really appreciate the time you have offered me on this.  I dare chance some more. 

The DAC am purchasing has the AES/EBU input that I likely will want to use. Currently I have both a DVD player and a CD transport with optical and coax SPDIF outputs. I also have two 1.5 meter 75ohm RCA cables available for use. I would prefer to use these cables between both the DVD player and the CD transport and the new DAC to avoid use of the optical connection.  Obviously this is no problem for one of the two disc players however the other will have to be connected to the AES input on the DAC. 

It is the impedance issue that has me confused. I know that a XLR microphone cable lacks the proper impedance for digital use. AES when balanced is 110ohms as I understand it. I believe with my new DAC I would be using a cable in unbalanced mode at 75ohms. I guess I need to verify this with Audio Mirror. 

If one has an 75ohm RCA cable can one fit a male RCA to male XLR adapter for my needs?  How does the impedance of the adaptor affect this? Or, based on the first sentence of the wikipedia report, can one use a BNC/AES adapter at the DAC input if one has a 75 ohm RCA to BNC cable? 

Hi Mesch,

My reference to the fact that some equipment (mainly some pro equipment) provides a 75 ohm AES/EBU interface on a BNC connector was a lighthearted response to what appeared to be your not very serious reference to the possibility that your "mind may not be keeping up," for not having correctly recalled the kind of interface that is provided on the DAC. :-)

To connect a 75 ohm S/PDIF output to a 110 ohm balanced AES/EBU input you would need a device such as the following, as well as a 110 ohm balanced cable to connect the output of this device to the 110 ohm AES/EBU input:

https://www.bhphotovideo.com/c/product/395533-REG/Hosa_Technology_CDL_313_CDL_313_Data_Link.html

Using simple adapters to connect an unbalanced 75 ohm S/PDIF output to a balanced 110 ohm AES/EBU input **might** work in terms of functionality (i.e., it may play music), depending on the specific equipment, but it would be very unlikely to be sonically optimal.

Best regards,
-- Al

Al, I am slowing down to allow my mind to keep up. :-).  I have decided that I will hook up the CD transport via RCA, and the DVD player via toslink and reserve the AES input on the DAC for a server/streamer should I purchase one.

I began a search for adaptors and in that search I came across the data link box you provided a link to. Given that I only use the DVD player for video I have decided that toslink optical will be the best approach. A single quality glass optical cable can be had at the price of this box.

Thanks once again for your help. Have a happy New Year!

Sounds like a plan!  All the best to you and yours for the new year.

Best regards,
-- Al