jt1stcav Posted April 9, 2004 Share Posted April 9, 2004 My brother recently bought some NOS Sylvania 6V6GTs for his Dared VP-16 integrated, and the seller threw in a whole slew of those lil' Cardas RCA caps as part of the transaction. These solid nickel and brass shields fit over unused female RCA connectors in your preamp or receiver to eliminate EMI and RF noise absorption. He had quite a few left over and gave me two pairs to use on my preamp's unused connectors. They're of solid construction, and fit nicely over the connectors, not being too loose or too snug. But do they work? Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted April 9, 2004 Author Share Posted April 9, 2004 Is anyone familiar with these RCA end caps? In your opinion, do you think they really suppress both EMI and RFI from entering the chassis through the RCA dielectric? Or are they really nothing more than fancy dust covers? They don't seem to adversely affect the sound of my preamp that I can detect, so I will keep them there for the time being...unless someone else knows otherwise! Whaddaya think? Quote Link to comment Share on other sites More sharing options...
Deang Posted April 9, 2004 Share Posted April 9, 2004 Well, they're relatively inexpensive -- and like most tweaks -- even if they don't do much, they generally can't hurt anything. I do think the concept is sound, which is why I use braided speaker cables (RFI and EMI shielding). A cheaper way of doing it is the what Craig suggested -- just use some of those rubber vaccum valve covers you can get at an auto parts store. Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted April 10, 2004 Author Share Posted April 10, 2004 That's what I thought, Dean...thanks. They can't hurt, and I sure couldn't beat the price (FREE)! I had braided Kimber Kable 8TC speakers cables for my Magnepans...sounded fantastic with 'em. But when I connected my Cornwalls to them (with the 200 watt McIntosh MC7200), the sound seemed a bit too bright for my ears (the Orbeck Stratti seemed to tame the highs somewhat...who knows, it's probably all in my head). But I never detected any EMI or RFI that I know of...how would I know if I did? What kind of grunge would I hear, or would the music be smeared or have a vail over it? How would I know if these Cardas caps really do anything, beside keeping dust out of the connectors? Quote Link to comment Share on other sites More sharing options...
Deang Posted April 10, 2004 Share Posted April 10, 2004 I'm using the 8TC right now, and I sure can't find anything to complain about. It's funny -- I have no idea what it would sound like with RFI or EMI bleeding into the system. I guess it would be low level hum -- hell, I don't know. I do know some areas people live in are more prone to the problem than others. Still, even if it's a bunch of B.S., like you said -- it's still a good idea for keeping dust and dirt out. Quote Link to comment Share on other sites More sharing options...
ben. Posted April 10, 2004 Share Posted April 10, 2004 Lots of EMI you'd hear as hum, pitch depending on the frequency of the offending source. RF is different story. While it could conceivably smear things up a little bit somehow, the frequencies are well out of our hearing range (but perhaps within our perception - that's a whole other topic). The caps seem like a good idea to me. I've been fooling around a tiny bit with those ferrite beads. I can detect a subtle difference when placed around the phono IC. It's hard to say, as I've got some grounding work to do yet. An appliance manufacturer is making them available as a fix for electrical noise in the ignition system of gas ranges. I figure if they are buying thousands of them for warranty repairs, they've got to do something. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted April 10, 2004 Share Posted April 10, 2004 Actually in most well designed gear none of the above is needed the unused input should be compeltely disconnected from the rest of the amp/preamp at the selector switch or even better have self short RCA jacks like I believe the Blueberry preamp uses. Craig PS Dean I think the rubber covers we talked about are a brain fart on my part and they won't block out anything sorry. The only thing that can shield is a ground shield so the cardas product would be the way to go but only if you have a product that truly does allow it to bleed into the circuit most products will not and this would be a useless tweak Quote Link to comment Share on other sites More sharing options...
3dzapper Posted April 10, 2004 Share Posted April 10, 2004 I can see several uses for those Cardas caps. On vintage equipment with tinned RCA jacks. They would prevent tarnishing/oxidation on any unused ones after cleaning with Deoxit. Second by covering the inputs you don't use , they will prevent a wrong connection when moving equipment or swapping cables. (Craig, even your rubber ones would be useful for these purposes.) Rick Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted April 10, 2004 Author Share Posted April 10, 2004 ---------------- On 4/10/2004 8:13:38 AM DeanG wrote: I'm using the 8TC right now, and I sure can't find anything to complain about. It's funny -- I have no idea what it would sound like with RFI or EMI bleeding into the system. I guess it would be low level hum -- hell, I don't know. I do know some areas people live in are more prone to the problem than others. Still, even if it's a bunch of B.S., like you said -- it's still a good idea for keeping dust and dirt out. ---------------- I was using the 8TC with the MC7200 and not the MC250, so there could've been a difference soundwise. Plus you're using your 8TC with your Quads; there could be a perfect matchup with your Klipschorns that I didn't seem to have with SS and my Cornwalls. Unfortunatly, my bro's got my 8TC now, so I'll never know what they could do for my Cornwalls and the BEZ 300B (if I ever get the damn thing)! The Cardas caps do seem like a good idea...seeing how I already have them in place, I might as well keep 'em there. It doesn't worsen the already great sound of my system, so they're keepers. I don't seem to have any RFI or hum problems here...I probably would've never bought the caps unless I did. But for free, hell...why not? Quote Link to comment Share on other sites More sharing options...
LarryC Posted April 10, 2004 Share Posted April 10, 2004 ---------------- On 4/10/2004 8:13:38 AM DeanG wrote: It's funny -- I have no idea what it would sound like with RFI or EMI bleeding into the system...I do know some areas people live in are more prone to the problem than others.... ---------------- I had big RFI problems in the past, as intrusion of radio and buzzing on my phono, probably worsened by the high gain needed for an MC cartridge. This area (DC/Maryland) is supposed to be notorious for RF. The problem got worse when I switched the preamp to "record," which un-shorts the unused inputs as I understand it. It seemed to be helped by packing aluminum foil around the inputs/outputs behind the pre, supposedly to help screen it out. Unfortunately, the Cardas caps made little or no difference. Larry Quote Link to comment Share on other sites More sharing options...
garymd Posted April 10, 2004 Share Posted April 10, 2004 ---------------- On 4/10/2004 2:39:59 PM larryclare wrote: ---------------- On 4/10/2004 8:13:38 AM DeanG wrote: It's funny -- I have no idea what it would sound like with RFI or EMI bleeding into the system...I do know some areas people live in are more prone to the problem than others.... ---------------- I had big RFI problems in the past, as intrusion of radio and buzzing on my phono, probably worsened by the high gain needed for an MC cartridge. This area (DC/Maryland) is supposed to be notorious for RF. The problem got worse when I switched the preamp to "record," which un-shorts the unused inputs as I understand it. It seemed to be helped by packing aluminum foil around the inputs/outputs behind the pre, supposedly to help screen it out. Unfortunately, the Cardas caps made little or no difference. Larry ---------------- Larry, Next time you're over, we should do some tinfoil tweaks. Any recommendations on brand? Reynolds OK? Shiny side in or out? Actually, I have no idea what RFI or EMI sounds like either. Have you ever heard either of these acronyms coming out of my speakers? Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted April 10, 2004 Share Posted April 10, 2004 Gary, You mentioned having some hum problems. It's probably related to RFI and EMI. Quote Link to comment Share on other sites More sharing options...
LarryC Posted April 10, 2004 Share Posted April 10, 2004 ---------------- ---------------- Larry, Next time you're over, we should do some tinfoil tweaks. Any recommendations on brand? Reynolds OK? Shiny side in or out? Actually, I have no idea what RFI or EMI sounds like either. Have you ever heard either of these acronyms coming out of my speakers? ---------------- No. It's supposed to be a picking up of radio transmissions or a raspy buzz, rather than, say, hum. I would hear faint radio or TV broadcasts or ham radio-like transmissions. My higher MC phono gain is more likely to pick that up than your mere MM cart input, so I doubt you have a problem. I've been told that aluminum is suitable for blocking RF, again unlike hum. Larry Quote Link to comment Share on other sites More sharing options...
garymd Posted April 10, 2004 Share Posted April 10, 2004 ---------------- On 4/10/2004 3:18:34 PM Guy Landau wrote: Gary, You mentioned having some hum problems. It's probably related to RFI and EMI. ---------------- I have a very faint buzz (not hum) through my altecs that you can hear only with your ear up to the speaker. I believe I can get rid of it with a 2-prong adaptor but it's not really an issue. I don't usually have my ear to the speaker when listening to music and it doesn't increase with volume. Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted April 10, 2004 Author Share Posted April 10, 2004 So is this the same reason why these damn Florida rednecks cover their windows in their trailers with aluminum foil? I just thought it was a cheaper alternative to using the Rebel flag as curtains! Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted April 10, 2004 Share Posted April 10, 2004 ---------------- On 4/10/2004 3:45:10 PM garymd wrote: ---------------- On 4/10/2004 3:18:34 PM Guy Landau wrote: Gary, You mentioned having some hum problems. It's probably related to RFI and EMI. ---------------- I have a very faint buzz (not hum) through my altecs that you can hear only with your ear up to the speaker. I believe I can get rid of it with a 2-prong adaptor but it's not really an issue. I don't usually have my ear to the speaker when listening to music and it doesn't increase with volume. ---------------- Sorry for the mistake, buzz was the exact word I was looking for. I have it too, and didn't have it when I lived in PA. NYC is known for RFI EMI problems. Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted April 10, 2004 Author Share Posted April 10, 2004 Which brings up a good point...I have no buzz through my system, even with my ears pressed up against the tweeters. But my brother does have a faint buzz through his KG 3.2s and his Dared VP-16 tube amp. Tube rolling did nothing to reduce or eliminate the buzz, same too with swapping out different power cords and interconnects. He uses a Monster Power HTS 2600 PowerCenter, but didn't have any buzz emitting from his system when he used his Adcom GFA 5400 and ARs, Acoustic Energy, Tannoy, and Triangle loudspeakers. I fear it's due to his new Dared tube amp. It's not noticable at all from his listening position, and it doesn't distract him from the music. But it's there nonetheless, and it bugs him to no end! Quote Link to comment Share on other sites More sharing options...
Audio Flynn Posted April 10, 2004 Share Posted April 10, 2004 These solid nickel and brass shields fit over unused female RCA connectors in your preamp or receiver to eliminate EMI and RF noise absorption. ++++++++++++++++ Moderate but hard to totally eliminate. RCA shorting termination plugs on unused inputs is a good idea. The white paper from www.virmode.com goes inot great depth to abate EMI influence in CD players. Quote Link to comment Share on other sites More sharing options...
Audio Flynn Posted April 10, 2004 Share Posted April 10, 2004 A theroy I buy into is that audio system components themselves and to a lesser extent nearby household appliances create EMI that affects sound quality morew than any other factor. Quote Link to comment Share on other sites More sharing options...
LarryC Posted April 11, 2004 Share Posted April 11, 2004 ---------------- I have a very faint buzz (not hum) through my altecs that you can hear only with your ear up to the speaker.... ---------------- One more thing, Gary, in my personal experience: the airborne RFI I had -- the intermittent appearance of faint radio transmissions and buzzes -- varied as I moved toward and away from the preamp, apparently because I was becoming part of the antenna system for the airborne RF landing on/in the preamp! I was told this was typical. I'll bet your hum/buzz isn't affected that way. Unfortunately, the Cardas caps didn't help that a bit. Larry Quote Link to comment Share on other sites More sharing options...
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