Do I need an expensive digital cable?

I was someone who NEVER would have thought digital cables matter, but I compared two USB cables and there was a difference in sound characteristics compared over two different very good systems by multiple people.  This hobby is full of surprises.  

@parkergetdean 

I think their kids said it.

@audio-b-dog 

24 bit is not a size of a network packet. 

192khz/24 is 192khz sampling rate with 24 bit depth. It is high resolution compared to 44khz/16 which is a sample rate and a bit depth of a redbook cd.

It has everything to do with resolution of audio and nothing to do with data packets transferred over network.

I think your understanding is incorrect and incomplete. 

@audphile1 

I have no idea what a bit depth is. Where did you get that information? A bit is basically on/off. A bite is a group of 8 bits which can represent 256 things. Digital packets consist of bites. They have all sorts of complexities, such as handshakes so that the sender and receiver verify what was sent. I have never heard the word "depth" used when talking about digital transfers. Could you explain please?

I just spent $14.00 on a one meter 75 ohm coax, just to see if it makes a difference when compared to the RCA analogue cable. That should give me somewhat of a baseline. I am still not convinced that the clock on my Moon's DAC does not supercede the transport's clock. I'm waiting to hear from Moon. (I can never remember the spelling of their company's name.)

@audio-b-dog 

Networking was one of them. I think that networking is done in packets

Spot on for computer networks, where it is critical that data is precisely the same when received as when sent. To achieve this, additional data is included in each packet so that errors can be detected, and either corrected or the packet is re-transmitted, multiple times if need be.

If packets have to be re-transmitted, there is an obvious timing problem!

When data networks started to be used to transmit sound, initially for telephone conversations, timing became critical and, as the pharmacist advert claimed, we dispensed with accuracy.  Entire packets could be dropped, usually without throwing away the gist of the conversation if enough timing was preserved.  The technique of discarding packets was called streaming, which aimed for a fairly steady stream of packets, even if some had to be dropped.

Suddenly all the arguments about "bits are bits and are always perfect" vanish, just like the bits that have been dropped.

Now we have to delve a bit deeper, to see which parts of our networks actually stream, and which parts implement full error detection and recovery.  It does not help that the main network protocol in use today, Internet Protocol (IP), is designed to connect a network of different networks.

Indeed, as its fundamental level, IP uses two different protocols, one called Transmission Control Protocol usually written as TCP/IP, and one called User Datagram Protocol or UDP/IP.  By now it should be no surprise that TCP guarantees data integrity but not timing, while UDP prioritises timing at the expense of data integrity.  Which would you choose for streaming?

Surprisingly, some streaming service providers like Qobuz do choose to use TCP but then you have to ask "at which point is TCP handed off to a different technology that does not perform error detection and recovery".

Sometimes the answer is easy.  For example, I2S does not perform any error detection, let alone recovery.  It was only designed to allow two chips on a board to pass 16-bit PCM.  So you can't complain if you hear audible differences if I2S is anywhere in your chain.  I2S bits ain't perfect.

What about Universal Serial Bus (USB)?  USB manages to transfer data perfectly between disks and memory, after all.  But wait, USB also has a streaming mode which - you know the story.

Ethernet then?  Same deal.  Can be made reliable if TCP/IP (or some similar higher-level protocol) is used end-to-end with Ethernet in the middle.  But then you cannot guarantee timing.

The above ignore secondary effects like Electro-Magnetic Interference (EMI) interacting with your sensitive electronics.

Hope this helps