Difference in sound between copper and silver digital cables?

For a digital cable? No. Heck no. Zip. Nada. Zilch.


Construction can make big differences in noise, impedance, etc., but for a digital cable for audio if properly constructed silver or copper will make 0 difference. Emphasis on proper construction for material properties. 


W.r.t. the RCA connectors good for 50, 75, 100 ohm. No. Almarg you are too nice. First, pretty much no RCA is correct for characteristic impedance so likely the RCA stated was just equally bad for all impedances and hence little difference would be seen.


People will perceive differences and then try to assign them to something they understand even though they have no idea why the difference (or even with certainty that there is). That may sound harsh, but true.  In a high quality DAC, signal jitter can be virtually eliminated. It's not the 90s any more.

Silver is a better conductor than cupper.  But you can also hear the difference, and that’s the reason why you have to choose between both.
it depends of 2 things: 1: do you like to hear it a bit sharper, detailful?: Ag.. More neutral : Cu. 2 : it departs also from the equipment: how sounds your system: sharp, neutral,dull. You have to find out for yourself what sounds best for you in the entire system. Always search for the best match.: in my system Nordost silver.

Inakustik -- another expensive digital cable. I paid that much for my Synergistic Research digital back in the day, but I'm retired now, ~$300 is my budget.

Is there a difference in sound between copper and silver digital cables, or purely in the implementation?

Yes there is a difference. But implementation definitely still matters.

Take for example Synergistic Research Element cables. Element Copper and Element Tungsten are different only in the two metals. Its pretty easy to hear the differences. This is just as true by the way whether its speaker cables, power cords, analog or digital. Element CTS combines three separate cables, one of each element, and yes what you hear is the best qualities of all three combined.

So there clearly are differences in sound between copper and silver. But compare either SR Element with another cable using the same metal but made by someone else and it will be obvious just how big a role implementation plays in it.

It still boggles my mind that in this day and age we are still talking about digital as if it mattered. Because it doesn’t. Please see above. Wire is wire. How it sounds digital is how it sounds analog is how it sounds between components or the power from the wall. Or inside the speaker for that matter. Its wire. It matters. Wherever it is.