Do I need an expensive digital cable?

@audio-b-dog I wasn’t suggesting a new streamer. I think there might be more potential to uncover with your Moon. 

I don't think the Moon needs better cables. The dealer who sold it to me made sure I bought good XLR cables. I think the Moon sounds very good. I will test out the CD player against 44.1 kHz streamed files to see which sounds better. I have read audio threads in which people have said that CDs sound better than 44.1 kHz files. There is no doubt that any digital files with higher resolution sound better than CDs. I have a few new threads in mind, but I need to find the time and energy. 

@audio-b-dog 

I have read audio threads in which people have said that CDs sound better than 44.1 kHz files

By pure coincidence I came across this article today in HiFi+: Reiki Audio JundoStream Reference: A Game Changer - hi-fi+.  The digital cable in question is an Ethernet cable with four teased-out twisted pairs and an eyewatering price tag of US$4,350 per metre.

Naturally the reviewer heaped praise on it but then came this paragraph which is based on the proposition that local storage (especially CD or SACD) is inherently better than streaming.  This megabuck cable only narrows the gap!

There’s usually a difference between stored and streamed music, and many still feel there’s an even bigger difference between music played through a network and that played directly from a CD or SACD. JundoStream helps level the playing field. It narrows the gap between physical discs and streamed or networked music. It also makes online and ‘locally grown’ sound closer.

I’ll postulate why this is so. 

Ethernet on its own is not an error-free transmission medium.  It needs a higher-level protocol like TCP/IP to deliver error-free digital bits.

TCP/IP has to run software in the receiving device, which hand-shakes with the sending device.  Many streamers have this software embedded in a specialist app(lication) like Qobuz which means bits streams can be error-corrected as far as the streamer.

When you need to connect a streamer to a DAC over say Ethernet, that connections has to run TCP/IP (or similar) at both ends to ensure error-corrected transmission. My guess is that streamers and DACS do not use TCP/IP for the final leg, so the digital stream can become corrupted.

It is worse with I2S as there is no error detection or recovery at all.

I assumed that the network packets were error corrected. But i haven't really looked into it. The dealer who sold me the streamer said that he had stored his CDs on a hard drive but streamed files from Qobuz sound just as good. He doesn't bother with his stored files. Anyway, over the next several weeks I will be able to evaluate Qobuz files against my CDs. Tomorrow, however, I will listen to a new (to me) mono vinyl album of Furtwangler conducting Beethoven's Ninth at Bayreuth. 

@audio-b-dog 

Knowing yourself is key to really enjoying high end audio. It sounds like you know yourself. You consistently use words like good enough and decent enough. So, it sounds like you are doing a great job of optimizing your system around your values. 

Some of use are obsessed and strive for the very best possible for skill and financial situation and put a premium on small steps in that direction. So, $5K speaker cables are easily justifiable (as my partner she loves to tease me when I balk at "the good TP") for the incremental performance increase. This is why I have these cables and interconnects throughout my system. 

Remember when you listen to a your new mono vinyl album of Beethoven and make a conclusion about the sound, you will be making a conclusion about your turntable, phono stage and the rest of your components as well as the recording.