Optical vs coax vs spdif

The local classical radio station 101.1 FM DALLAS. Is giving away their entire CD collection at MY restaurant!!! Awesome 😎, but I haven’t used a CD player in my setup in years. I got on eBay and scored a Marantz PMD321 for like $50 bucks including shipping. 

i want to use my dac (simaudio Moon 280d) but I don’t know what kind of digital connection would work best. 

Should i I use optical, coax, or spdif... 

Andrew, I think the consensus opinion is to use coax over optical. There is also an opinion that 1.5 meters is the optimal length for a digital coax cable. Don't recall the reason for this opinion, but it did seem to have some technical merit if I recall correctly. Unless you hear otherwise, look for a quality 1.5 meter 75 ohm digital coax cable.
Best way to go is with S/PDIF coax. You'll need to get a cable with RCA connectors to mate with your DAC. And the quality and design of the cable makes a difference to sonics.
You should use the archives to research the different cables since this has been discussed many times. 

Most experts agree that 1.5 meters is the optimal length for digital coax. It has to do with having minimal reflections of the data stream as it passes from CD transport to DAC.

You’re going to hear the term jitter used frequently. This "jitter" needs to be controlled and minimized in digital playback. A well designed cable is a key element in preserving the quality of the signal.

Wow thanks guys! I have some  Old audio quest YIQ – 3 75ohm composite video cables, I bet they would work in a pinch. Oh I should mention that the Marantz also has digital coax out. 
the Marantz also has digital coax out
Yes, I looked at the images. That's the RCA SPDIF coax that you will use.
And I'll be interested in how your 75ohm cables sound.

I’ve never heard any consistent difference between optical and coax using a variety of transports into a variety of DACs.  I have consistently heard a difference with usb vs the others, and usb always loses
Depending on the rest of your system and given the quality of the sound in a restaurant environment, the choice of the connection (and the cable)  may not and probably will not make an audible difference.  
Congratulations on getting the CD collection.
@kalali thanks 🙏 the radio station is giving 10 free cds from their library to anyone that comes in tomorrow, if your in dallas Texas stop by New York Sub I’m university park. The CD player is for the home system. Which is pretty badass. 
@lowrider57 the cables sound fine.  To be honest I was actually impressed with the soundstage but I haven’t listen to a CD on a high fi system in quite a while. Are usually listen to my turntable or my DAC with roon. I’m going to get a proper connection and use the AES output. I’ll let you know if I hear a difference 
I've done A LOT of listening over the years to the various digital connection types.  On super expensive gear to mediocre gear.  Almost without fail, I rate them as follows:

1.  I2S  (pretty rare and very equipment specific)
2.  Firewire   (pretty rare and very equipment specific)
4.  Coax on BNC
5.  Coax on RCA
6.  AT&T ST Glass Fiber
7.  Toslink
8.  USB

Of course this is just my opinion, on my system, in my room and with my music...

Would the same opinion about the signal quality of USB also apply using a Synology NAS to endpoint?

Just my humble opinion that I gathered in over 30yrs+. The implementation of each format dictates the transmission quality/fidelity of each. Having no exposure with FireWire and USB, I can’t comment on those. My personal order of preference is as follows:

  1. (Provisional) I2S - Had great success with the original mini-I2S ala Audio Alchemy days, specifically Audio Magic cable and still serves as my short cable reference. It’s like no cable at all.
  2. AT&T ST - Champion of long cables. I’d been using lengths varying from 18” to 60’ for over 3 decades. It consistently better all other formats I’d tried. (Disclaimer; Didn’t have long enough I2S to compare). One main advantage of using ST cable is total electric isolation between Transport/front end and DAC/back end. Professional recording studio once used this as their universal standard. But again, circuit implementation and cable dressing also plays a very important role.
  3. AES/EBU - Far from being an exhaustive sample, I’d tried quality cables from XLO, Kimber, Tara Labs, Acoustic Zen, Audio Quest, etc. It is a slight step behind ST for extended length. At the risk of generalization, I found AES/EBU’s character to be a touch matter of fact. Great impact but not as flowing and transparent as ST. For years, I had been using a 60ft Canare DA206 110ohm to supplement my long ST with good success.
  4. S/PDIF - Great performances can be found with cables that strictly adhere to true 75ohm. BNC is the de facto standard and offers the best performance. With few exceptions, phono type connection isn’t true 75ohm and may degrade signal transfer. One should also avoid Coaxial/BNC adopters when possible. My long term favorite is Kimber D-60. Still have a few sprinkled across 4 systems. I recently discovered a fantastic prefabricated cable from Cable Solutions. I’m using a 62’ length Signature Series 77 carrying 24/96 with excellent results. The beauty is in their true 75ohm coaxial connectors. Cost of their 1M is $37.37 and I personally believe that you have to spend up to 10x to equal.
  5. Toslink - I call them Toss-a-link. Some went as far as disabling their equipment’s Toslink transmitter. So enough said.

Since this is only my personal preference with my specific systems, your finding may and will differ.

Best Regards


PS: My preference between the Canare DA306 and Signature Series 77 is like splitting hair.

@dtximages my restaurant is New York Sub. We’re at traditional New York deli but we source all of our meats from local ranchers in Texas and make everything from scratch including roasting smoking and curing meats, homemade pickles and ice cream. Etc 
try the smoked brisket pastrami