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.

After experimenting with shorting caps on preamp inputs, my conclusion was that the plastic dust covers already provided with Accuphase products do just as well (in other words there were no perceived sonic differences using a metallic composition cap at least in my experience). These plastic Accuphase dust caps may be available separately from one of their dealers such as Audio Unlimited in Colorado

I got some from Virtual Mode (http://www.virmode.com/ -- but note that their web site doesn't list all the accessories) for $2 or $2.50, I think; definitely not $3. They sell different ones for analog and digital outlets.

If you do a search for *SHORT OUT PLUGS* You will find a thread I started awhile back that will teach you how to make your own using parts from Radio Shack. I must have made 30 or so for about a buck a piece. Better check your manuals before you start randomly plugging them in. My Theta gear recommended them for unused inputs only (NO OUTPUTS) I would recommend just using dust caps for the outputs, which you could probably make yourself just eliminate the shortout and soldering step. Good luck

These caps do nothing but they look nice -- if you walk around your stand to look at them. A sheet of Mumetal does a lot more to block EMI or RFI than these caps.

Do they really short out the input/output? Will the new XLR also short out. Not being an engineer, but that sounds like it could be harmful to some of the electronics.
I hope someone very knowlegeable about this (engineer) would answer this.

The Cardas plugs are not "shunts" or "shorting plugs". A shunt is something that ties your "hot" to "ground", either directly or through a preset impedance. The Cardas pieces are simply metal "lids" or "shields" that slide over your unused RCA jacks. As such, they are safe for any RCA since there is no electrical connection being made.

As to using shunts on unused RCA jacks, they should only be used on INPUTS. NEVER "shunt" an output or you WILL do damage to the component. Unused outputs would be a good place for the Cardas pieces or similar designs. As a general rule, shunts are far more effective at lowering the noise floor, minimizing the effects of RFI and eliminating crosstalk between unused inputs when directly compared to "RCA covers". Some preamps, etc... may have side effects such as oscillation or sudden changes in sonic character from using shunts / shorting plugs. This is typically due to a poor design and circuit instability. Needless to say, this can occur with ANY piece. This is regardless of make, model or expense IF it was poorly designed to begin with.

I would HIGHLY recommend doing a search via the archives and look up some of the threads. You might want to enter either "shunts" or "shorting plugs" as the subject. Sean
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