RCA End Caps

I use the Cardas caps on ALL unused RCA jacks in my system: analog inputs and outputs, digital inputs and outputs, etc.

Cardas even makes an XLR version that I might add to my system for unused balanced connections.

Both varieties are somewhat expensive, and their efficacy is entirely system-dependent. I like them, though.

I do not know of a competing brand for these items.

I bought the end caps, slid them on and ... well, not much really. The theory sounds right though: I won't take them off because they really should work. Maybe I missed something or, as suggested, maybe they really are system and environment dependent. Did you try the aluminum foil to see if it makes any difference for you? If it does, it's still a reasonably inexpensive tweak. Cheers.

These are leader items, are almost loss leader items.

I suggest you go down you your local machine shop with a block of nickel and brass.
Ask them to CNC machine it into an RCA cover.
Let us know what they charge.
I assure you it won't be $3 for one, or even $3 each for a 1,000.
These CNC machined blocks of a nickel and brass mixture are a bargain.
If you are judging these by their size than I suggest you check out what diamonds are going for.
You will be shocked....

These are a bargain. CNC machined nickel and brass or plastic for about he same price?
Not a tough choice.

How well do they work? Depends on how much of a problem you had in your systems environment in the first place. Keeping the dust off of, and out of, unused RCAs alone justifies their cost
(plus they look good).

BTW, these items are also made in the U.S.A.
Brian

PS the XLR caps are also out.