[maxwalrath]

http://cls.audiogon.com/cgi-bin/cls.pl?accstwek&1158167061

Do these things or the Cardas RCA caps make any noticable sonic changes?  .

[marvda1]

these plugs only protect from dust, it is my understanding that the cardas not only protecct from dust but protect against emi/rfi entering your system through unused inputs.

[maxwalrath]

Yeah I noticed the rubber thingys don't mention emi/rfi blocking. Any Cardas users notice a sonic benefit?

[Bob Reynolds]

I've looked at the Cardas RCA caps off and on for a long time. I finally decided that the RCA plug being at most 1/2 inch long would not make much of an antenna, at least, not in comparison to the IC cables. If you're not using shielded ICs you have bigger concerns than the unused RCA plugs.

[Doublej]

Does anyone sell a product similar to the Cardas caps at a much more reasonable cost? $7.50 for 12 is the right price if they are metal and potentially block EMI/RFI.

[Carlman]

I use them as dust covers... It's amazing how much dust settles over time behind gear, and over time pits the metal... Of course, if you're constantly changing gear, it's of no consequence.

ZERO sonic difference... just dust caps for me.  The Chinese make little red and white plastic caps that do the same thing... if you could find them, I'm sure you could get about 1000 for the price of 1 cardas.... and have dust free RCA's. 

-C

[maxwalrath]

I moved recently and just got cable and internet today.

Now that the cable box is hooked up, the Modwright preamp can't be plugged in without a strong hum coming from the TV.  I can plug the Patek poweramp in without issue, but once the Modwright hits the wall there's lots-o-noise.  I now have the TV plugged into the cable box, and the cable box/video games plugged into an outlet in a different room, but the noise hasn't gotten any better. 

Is this exactly the AC noice curruption that these little plugs can prevent?  I need a solution quick....

[mtodde]

I moved recently and just got cable and internet today.

Now that the cable box is hooked up, the Modwright preamp can't be plugged in without a strong hum coming from the TV.  I can plug the Patek poweramp in without issue, but once the Modwright hits the wall there's lots-o-noise.  I now have the TV plugged into the cable box, and the cable box/video games plugged into an outlet in a different room, but the noise hasn't gotten any better. 

Is this exactly the AC noice curruption that these little plugs can prevent?  I need a solution quick....

This sounds more like a ground hum on your cable TV cable.  You can get a ground buster for less than $10 from Parts Express. 

The Cardas caps may help some with this issue but I'd try something for grounding first.  I found the Cardas caps did make a difference...particularly with the unused 2nd phono input on my old pre.  The plastic dust caps only keep out dust while the Cardas caps do block some RF.

[PSP]

I went to RatShack and bought a large number of the cheapest red and black plastic RCAs they had.  You solder a wire across the pins (center to outer conductor)--I used cat5 because I have a lot of it--and put these shorted RCAs into every one of your preamp's unused inputs.  This keeps dust out of your preamp and reduces RFI, EMI, and hum.  RCA quality is irrelevant in this application.

Do not short the outputs!

IMO, the Cardas covers would work well for unused RCAs on source equipment (ie CD/SACD players, etc).

Peter

[Mike B.]

For years people have made these using old cheap male rca plugs. They run a jumper from the hot to the ground.

[Bob Reynolds]

I moved recently and just got cable and internet today.

Now that the cable box is hooked up, the Modwright preamp can't be plugged in without a strong hum coming from the TV.  I can plug the Patek poweramp in without issue, but once the Modwright hits the wall there's lots-o-noise.  I now have the TV plugged into the cable box, and the cable box/video games plugged into an outlet in a different room, but the noise hasn't gotten any better. 

Is this exactly the AC noice curruption that these little plugs can prevent?  I need a solution quick....

I agree. It sounds like the classic ground loop caused by the cable. You can do a web search for "ground loop cable tv" and you should find a lot of info. Usually, you want to locate the ground point of the cable service for your house and make sure that it is clean and tight. If that doesn't help, then a cable isolation transformer is usually the next step. I use a Jensen Iso-Max.

You could give us a little more detail on how everything is connected if you can't get it resolved.

Good luck,
Bob

[TheChairGuy]

I found the same as Carlman...they (the Cardas caps) work as nice dust plugs offering no sonic benefit noted.  The best price I found was right here at AC's own DIYCable.com where I bought mine:

http://www.diycable.com/main/default.php?cPath=26_44_51

The Tweek Shop near me in Santa Rosa, CA makes shorting plugs for $6.00 a pair if you're not handy (as I am not solder-capable, or frankly want to be).  I have no idea if they work better than the Cardas caps...but I seem to remember shorting plugs were standard equipment on equipment 30+ years ago.  Maybe dust or some sonic benefit (lower RFI/EMI entering the system?)

http://tweakshop.com/Shorting%20Plugs.html

[Soundbitten]

I purchased the Cardas Caps when Musicdirect proclaimed them the # 1 bargain tweek ... what a crock of sh*t  that was ! Never heard one iota of sonic difference .   

[Doublej]

You can also asemble your own shorting plugs, no soldering required, by purchasing rca male to female F connectors and then adding a 75 ohm screw on F type terminator.

About the same price but a bit cleaner look to it.

Here's one example from Allied Electric:

Emerson Network Power
Adapter; RCA Male to F Female
Mfr's part#:    25-7530
Allied Stk#:    510-7530


PLUS
Bomar Interconnect Products
CONNECTOR ACCESSORY, RF COAXIAL, F 75 OHM TERMINATOR, USE ON JACKS AND RECEPTACLES
Mfr's part#:    F0884
Allied Stk#:    202-0234
Allied  Stk#: 202-0234

[TIC]

Sounds like the classic ground loop problem that many people have heard when cable TV is connected to any component in the system. Do a search on "Hum" over at AudiogoN. You'll read many post that provide a resolution. What you need is an in-line device that isolates the cable TV from your system. There are several models available from the $90 Mondial magic block down to cheap alternatives for Rat Shack and other places.

To test the theory, simply unplug the cable TV coax from you system. If the hum goes away, you know you have a cable TV generated ground loop.

Enjoy,

TIC

[Bwanagreg]

We've been talking about shorting plugs for the Promitheus Transformer Volume Control in another thread. Word is they can eliminate some noise from unused inputs on the TVC, a problem for this design in some installations. Here is a very cost effective option that Newbuyer found. Unlike the overpriced Cardas caps, these actually short the input. I've got a bunch on order.

http://www.wallcoinc.com/Calrad_30_486_RCA_Shorting_Plug_Gold_p/wal22-30-486.htm

[some young guy]

i've used them on my preamp and cdp. they did a great job at keeping the unused rca's dust free. i didn't notice any sonic benefit, but i don't have any rf or emi problems. i would use some caution with the shorting plugs though... not all equipment likes to be shoted, so ymmv.