Cardas caps

[music again]

Is there any value at all in capping unused RCA, XLR, S-video and BNC connectors?

The claim is that it eliminates EMI and RF noise absorption, as well as keeps away dust and corrosion. This is relatively inexpensive and if it has any merit, I would say . . . why not?!

Comments?

Thanks!

Joe M.

 

[risabet]

I do believe that there is a benefit in high RFI/EMI environments but why spend the money on Cardas caps, they are pretty but you won't see them. Instead use those cheap-assed ICs that come with most mass-market gear, cut them close to the RCA plug (about two inches away), connect the ground to the center pin and voila, shorting plugs for INPUTS ONLY never short outputs. I've found a lower noise floor when all unused inputs are shorted. YMMV.

 

[tonepub]

I like either solution if for no other reason than you don't accidentally plug something where it doesn't belong!

 

[music again]

Shorted plugs

I do believe that there is a benefit in high RFI/EMI environments but why spend the money on Cardas caps, they are pretty but you won't see them. Instead use those cheap-assed ICs that come with most mass-market gear, cut them close to the RCA plug (about two inches away), connect the ground to the center pin and voila, shorting plugs for INPUTS ONLY never short outputs. I've found a lower noise floor when all unused inputs are shorted. YMMV.

That brings up another question from me . . .

What is the difference between just covering the connector with a "regular" cap and "shorting" the connector? I noticed some pins, including shorting pins from Cardas, have a center pin that slips into the hole. Does that center pin cause the "shorting"? What advnatage does a shorting pin have over just plain covering the connector?

Thanks!

Joe M.

 

[risabet]

The caps will keep the jack clean. The plugs will short the RFI to ground which is the point IMO. EMI (which is magnetic in nature) is another story and is probably not effected by either type of plug.

PS: some recommend using a 50 ohm resistor between hot and ground to protect circuits with DC servos.

Check out this thread on Audio Asylum http://db.audioasylum.com/cgi/m.mpl?forum=tweaks&n=116118&highlight=shorting+plugs&r=&session=

PPS: A 75 ohm plug makes a great cheap tweak in unused digital outputs. This is OK as the output isn't shorted, it is driving a 75 ohm load.