Capped off?

"I’m really not
sure if I can tell a difference, but they sure look cool!"

Isn't that part of "high end audio"? 

They’re actually more for shielding your system/components from RF and EMI. Another positive is they help keep all of your unused connections clean. I’ve used them for years but with tin ears not sure I hear any difference. I do sleep better though knowing they’re there…

Using them big improvement.

If the caps have a pin then they are shorting-plugs and should only be used on RCA inputs. Not all components can use these.
Regular caps can be used anywhere.

+1 tube_gb

I use them as well....more to repel dust than for any sonic benefit. I really have no idea if they have any effect on sound quality.....but as you say, they do look good.

Shorting plugs are what is used for crosstalk. The plugs that you have are dust caps! This is what a shorting plug looks like!
https://www.amazon.com/Viborg-Stopper-Plated-Copper-Protector/dp/B017DH76VS/ref=sr_1_3?dchild=1&...

Just get the cheap ones with removable pins. Go whichever way works the best. 
If you gotta spend up, FutureShop UK is your best bet.

I don't know about Cardas, but if you were using the old PPT caps there would be no doubt. The reduction in noise, improvement in clarity, and image focus, is obvious and easy to hear. 

That's the problem with these things. Tweaks, I mean. Someone makes one that is truly outstanding. Everyone hears and says wow that is amazing. But then instead of buying the good stuff they decide to try something else. Which of course turns out to be crap. Or they use something that looks the same, and jump to the conclusion it is the same, and then in a Beamon size leap of logic conclude everything that looks like that is snake oil, to use this sites preferred vernacular.

Get the PPT ones. If you can. Anything else, oh well. 

@millercarbon, what makes one brand better than another; materials, design?
And do you use shorting plugs on inputs?

On the one hand I know a good deal about what and how. I know for example an otherwise perfectly ordinary plug can be transformed into something remarkable simply by putting a dab of goo on it. I know for example there is a reason for the little blob of gray goo on Synergistic Research Orange fuses, and it is for the same reason they tell you not to remove it. Also know something very much like that is going on with a lot of these things. 

So yes it is materials, and maybe a little design too. What materials? Aye, there's the rub.

Shorting plugs, if that's all it is, then they do nothing. The outside of the RCA is ground, and ground is ground. The inside is hot. Look inside any component you will see one wire, the hot one, going to the input selector. All a shorting plug does is connect that short little bit of wire to ground. That's it. Minus the shorting plug that hot wire was just sitting there disconnected from anything. With the shorting plug its now connected to ground. I leave it to you to imagine how much difference there can be from one foot of one wire not connected to anything.

As opposed to the magic goo. Which I guarantee you makes a huge difference.

MC, what is a PPT cap? Thanks.

I will get some caps just for the cool factor. Unless there’re people out there can really hear improvement, not difference, from those shorting plugs.

Tonight I placed shorting plugs into the inputs on my preamp. I have these gold plated plugs that were from years past. I'll need to listen for a few days to note any sonic change.

Maybe I'll get the dust caps for the outputs but I don't know if they provide any benefit.

How about those nice looking XLR caps in both males and females selling at Amazon? Anyone has tried those yet? They really look cool. 

The new stuff like a Mcintosh C2500. there is no long runs of wire because its not point to point. Its all pretty much logic board, with really short runs, and RCAs and XLRs are soldered directly to the board.

The "Shorting plugs" on Point to Point, Night and Day. You better, hook inside, to the outside of the RCA. Talk about clean it up. They are normally nickel, new stuff is gold. You can change that though, for the tweak guys.. I clean the heck out of the connections, with steel wool on a spinner, then, I treat them too.

I use gold "CAPS" on my new stuff just for looks. It has NO purpose other than to keep the dust OUT, cover the RCA, and look good.

PPT I thought it was Pin Point/point to point Termination, PPT caps, inside to outside.

XLRs? Flipper caps, they do get dusty inside..without covers, though.

Regards

Great info, thanks.

A bit confused...

I made "shorting" plugs years ago for unused RCA inputs on a couple of phono preamplifiers.

I wired a small resistor from the RCA's center post to the RCA's outer band (as I was instructed to do).

Forget the value, but it was small.

There was a marked sonic improvement, though the (2) preamps were inexpensive battery powered stereo units that I ran as dual mono's for stereo (simple way of beefing up the power/battery supply).

DeKay

I bought a bunch of no name RCA caps and also caps for my unused XLR ins and outs on eBay. At the very least, it keeps the unused inputs and outputs clean. Never heard a difference although my systems are dead quiet to begin with.