[Johnny2Bad]

Caps are supposed to fleece you of your money, and that's what they actually do. The size an open RCA exposes to RF isn't an issue. Longitudinal vents (as compared to perforated round hole covers) are more open to RF than an RCA, and plenty of gear employs them.

Plugs (shorting plugs) are supposed to reduce noise on that input and possibly lower noise when you are using another input by reducing crosstalk, and that's what they actually do (the noise spec in the spec sheet is with the input shorted).

Resistors are not necessary but might save your butt if you accidentally use one on an output, but note that a plug with a resistor is by definition not a shorting plug and may not give you the noise spec from the spec sheet (resistors add noise, and as the value increases, the inherent noise rises). Probably not enough to worry about (and why would you be listening to an input that has a plug, resistor or no resistor) but there you go.

DO NOT use a shorting plug (ie without resistors) on an output, and it's general good practice to not use them at all on outputs, due to the risk if no resistor is present.

Back in the day Luxman used to include shorting plugs with their preamps / integrated amps / receivers.

[Speedskater]

As 'Johnny' just wrote, the holes are way too small for any real world interference to get in.  In most hi-fi components, interference can several much more accessible paths to get inside.

[charmerci]

When I made mine I used the resister, I have no idea if it makes a difference. I do know that if you are trying to protect against RFI/EMI you need to buy shorting plugs not just plastic plugs.

How many are you looking for? I may have some around here but would have to look.

Greg

Ten. That would be awfully nice! 


Thanks for the replies.

[lokie]

I have three outputs on my preamp. One is unattenuated and throws out full volume which i think is used for a tape out. I've been thinking of putting a plug on it, so I don't make the mistake of using it as an output as I have done on occasion. They are unmarked and I forget which is which and I'm feeling around the back blind w the pre in the cabinet.

I assume they do no harm?? Any cheap ones out there?

[who?me?]

I have three outputs on my preamp. One is unattenuated and throws out full volume which i think is used for a tape out. I've been thinking of putting a plug on it, so I don't make the mistake of using it as an output as I have done on occasion. They are unmarked and I forget which is which and I'm feeling around the back blind w the pre in the cabinet.

I assume they do no harm?? Any cheap ones out there?

At least caps keep the dirt and shit out of the RCA taps.
The plastic caps are cheap and disposable.
The metal caps are snake oil.

[who?me?]

[whoops, accidentally quoted myself]

[srb]

I've been thinking of putting a plug on it, so I don't make the mistake of using it as an output as I have done on occasion.  .....  Any cheap ones out there?

For the outputs you don't want shorting type, and if you're not trying to protect against RFI/EMI ingression, all-plastic caps will protect against dirt, oxidation - and in your case, accidental connection.

They are available in red/white packs and other colors for ~ $8/20pk or less.

RCA Phono Cap Cover Protector

[mick wolfe]

it depends on which ones you get, some just keep the dust out while others (shorting plugs) stop interference from coming in thru the unused ports.
here are the ones I use.  they also make one for digital inputs.
https://highend-electronics.com/products/highend-electronics-analog-terminator-shorties

I use these (highend-electronics) on my Schiit Saga's unused inputs. This is in my HT/casual set-up which I assume is more vulnerable to interference, etc.  I've also used their digital plugs (coded black) which deviate in that they're designed for use at the unused digital out of a CDP. And no, never did an A/B in or out comparison... so I can't substantiate the somewhat overenthusiatic reviews at the Hi-End site. All I can say is the system is extremely quiet with the plugs in place and there are no negative effects to my ear.

[charmerci]

So now my question is - because I'm on a budget. Can I buy these?

Well, I went ahead and got these. I may hear an ever so slight difference. Maybe, maybe not.


Eh, at least it makes the back of my preamp look nicer.

[navi]

I use them. My RCAs are less dustier these won't stop RF and other BS from entering your system.

[Johnny2Bad]

Although I know that some people are more concerned about dust than others, the real issue with RCAs (and other connectors) is environmental corrosion.

If you live in a high pollution environment, near the sea, or high smog area, your connectors will experience corrosive plating often enough that a six-month cleaning with DeOxiT / similar is probably warranted if you actually use the connection, and prior to any new connection, including prior to any evaluation of cable changes (remember to treat the old cable if you are doing comparisons). In a low pollution environment a yearly cleanup is probably a reasonable interval.

Using a cap probably isn't going to prevent such corrosion, as it comes from the air and ambient humidity and few caps are gas-tight.

If you choose to make your own consider a reasonable quality tight-fitting RCA intended for cable connection, without the cable, of course.

Switchcraft all-metal gold-plated can be had for a few dollars. I would recommend Neutrik ProFi but I find them loose fitting on some factory female RCAs. I use Canare F-10 ad F-09 simply because I buy them in bulk and have them handy, around $4 each. But any tight fitting RCA, including those with plastic bodies, will work.

At that point all you need to decide is if you want shorting plugs (solder the (+) and (-) connection points together) or safety resistor plugs (solder a resistor between the (+) and (-) connection points), or just use open RCAs and do nothing (same as a cap, not a plug).

For dust I would just allow it to accumulate within reason, and use a camel-hair artist's brush to remove it at whatever interval you see fit to follow.

[Armaegis]

For those who really want to keep out the dust/corrosion/etc, use some contact cleaner/enhancer/whatever before putting on the caps. The film will help keep out the gremlins.