Connections for NAD M51 DAC


I plan on purchasing a M51. I wish to use a audiophillieo2 on the COAxial input. I also have a Arcam DV137 which I use as a transport. I don't like using the toslink input. I could connect it via HDMI. The M51 also has an AES/EBM connection. The DV137 does not. Is the AES/EBM a balanced SPDIF input? Is it 75ohm? Are there adapters or cables that will convert the AES/EBM input to a single ended COAX input such that I might connect the DV137 via this route? Would that be better than the HDMI route? Thanks in advance for your help.
mesch
I have been using a lighting to HDMi connection with my iPad (streaming Tidal CD quality). I like it but I would like to try the other connections since the optical from my Apple TV sounds terrific with apple content and Netflix. Does anyone have experience with this? Is there a way to go to the AES/EBU connector, and if not, what devices output that way in digital (is it any digital device that has XLR 'digital' output)?
I just played some FLAC files in 24/96 on a hard drive through my BluRay player's HDMI port and it sounded incredible.....Time to buy some HD Tracks.......
The HDMI input works great with my Oppo BDP-83, allowing me to output SACD and DVDA thru the M51. I also output my Bryston BDP-1 using the balanced cable, and finally use the USB input from my computer.

Best sound? Hi rez files from the BDP-1 and SACD and DVDA from the Oppo.
Thanks Odd, After posting I did some research online and came to the same conclusion. Should have done research prior to posting. Would use AES only if I had a device that used that output.
I wouldn't get all hung up on connection, I have the M51 and have my BluRay connected via HDMI and my CD player connected via coax. It sounds great on all inputs. This DAC is the Swiss Army knife of DACs, it's awesome. The nice thing about HDMI is it can pull the HiRez stereo layer off the disc if so encoded. It will play 24/96 through HDMI and it sounds great. The coax of a BluRay will only pass 24/48k so I would say HDMI is the way to go for those with a 2.1 system like me. AES/EBU is a 110Ohm cable, I see no benefit from using any type of convertor to go SPDIF coax to balanced digital. Just try the coax and compare.....I doubt I could pick which input in a blind test, both sound exceptional.