Cardas Machined RCA Caps.???

I have seen many ads about the benefits of using these caps to avoid noise on the non-used RCA inputs...Somebody even posted an anouncement today at Audiogon.
Has someone ever tried these caps? Is it really beneficial and acoustically audible?
What do you think?
Yes, but you must cover all unused jacks to realize the difference. I mentioned in an earlier thread that I covered all unused jacks in my system for several weeks. I then removed them all and noticed that they did indeed lower the noise floor. I have since put them all back on, and I have also covered my unused XLR openings with Cardas XLR caps.
I use them, but I haven't really identified an audible difference. I live in an area where there isn't a lot of steady electromagnetic noise. Perhaps there is an audible improvement when a noise source comes close (e.g., electrically noisy diesel motor).

I understand the principle of better shielding, and I believe it is desireable. I believe my system can sound audibly better based on the cumulative benefit of a number of individually inaudible improvements, and this could be one such.
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I have then also. Can't swear they help, but not taking them off eihter. I also have good power and low noise to begin with.I consider tehm dust protection too.
The cardas units just cover the RCA instead of shorting the center conductor the correct way.

The shorting types work great on unused coax output and all unused pre-amp inputs.
This tweak cannot be heard on lower resolution or high noise floor systems.

Make your own and have at it!

I just purchased a bunch of these here on A'gon, and can say that they make a slight difference in the noise floor. They don't fix major problems and don't effect soundstage etc. but they weren't designed to do that. IMO, it all depends on how well your system is setup. If your cables are all squared away (power cables not touching or crossing interconnects) I think the improvement will be noticable. As a side note, they did make an improvement on my TV, the picture is a bit more crisp, I had some left over and went to my video side to use them. I didn't think it would do anything, but it turns out, they are great for that too! Improvements in 2 areas for a small amount of cash.

Some preamps don't like their inputs shorted, that is why Cardas makes their RCA Caps with no shorting center conductor.
I haven't noticed any sonic differences. I purchased them mostly to keep dust out. They are easy on the eyes as well.
One needs to be careful constructing shorting plugs. Some preamps get very unhappy when shorted. As mentioned earier... the Cardas Caps are "non-shorting." Be sure to check out the XLRs as well. They are another fine product by Cardas.
Someone wrote in the AA forum that you can test your system by putting Al foil caps on your un-used inputs / output.

If you notice a difference you can decide if you want to spend the money for nice looking caps.

I started with these when I was experiencing a problem with my phone pre amp. They may have cut down on the RF noise but I won't swear to it. I will say that the other two benefits are (one) no dust can get in the jack and (two) they look so cool! Small investment and decent returns, it's a tweak, tweaks are more than not, a waste of money, but fun.
I bought a very attractive set of these in August from Music Direct. I even paid a little more to get the cute little nautilus shell on the face. My application at the time was for a new Ayre AX-7 integrated I had just received. I thought that the caps and the adjacent Cardas speaker connectors would look like a matched set. Unfortunately, the Cardas caps were so loose on the RCAs they fell off without even touching them. I called Ayre about this and they informed me that there was no such thing as a standard size of RCA terminal and that this loose condition was a possibility. They did offer to put a different type RCA connector on the integrated that would accomodate the caps but I saw the whole thing as a worthless exercise in system downtime. The caps are in a drawer collecting dust now.