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75.45.110.11
In Reply to: RE: AC Outlets on Video Upgraded with great effect posted by tweakydee on January 22, 2011 at 12:05:40
Those outlet covers are metal? What kind of metal? For all the times I've been shopping at the Home Depot, I think the only metal covers I've ever noticed were the outdoor weather proof variety. Are the ones you purchased brass or zinc or are they aluminum?
What is the purpose of the carbon fiber weave? Just for decoration or something else?
Thank you
Follow Ups:
where do you buy Carbon sheet an ERS ?
thanks.
Some systems just aren't resolving enough to hear much of the grunge that plagues high end equipment--the grunge caused by RFI in particular. And speaking of plagues, this site has recently been under attack by a group of "objectivists" who almost never reveal what their own equipment is, and usually don't try any of the tweaks that they attack. In lieu of listening, they base their conclusions on on severely constricted view of the rules of logic and an even narrower view of the scientific method. Since some of the tweaks in question are only audible on highly resolving equipment, discounting them because of one's experience with mid-fi components is really irrelevant. Criticizing a tweak without ever trying it is unjustifiable--on scientific grounds.
Edits: 01/25/11
Back off Mr.
Go back and read carefully through all my posts/replies. I didn't criticize anyones "tweaks" I'm simply an inquiring mind wanting specifics and not vague wishy washy answers.Oh yeah, I saw YOUR criticism of my cables in an email forwarded to me from the forum.
The "ARCHER" cable I used wasn't made by Radio Shack, it is just rebranded so they could sell it. I don't know who actually made it, but it kind of reminds me of MOGAMI. It was on a mark down close out table. Anyway it isn't even innerconnect cable but is actually very flexible microphone cable, dual conductors with separate shield and drain. What really matters is that it is very low loss, low resistance and low capacitance per foot, which it is, that is why I choose to use it. I needed a rather long pair of very flexible innerconnects from my preamp to my monoblocks and anything decent was quite expensive. Just because I don't have xthousands of dollars to spend on innerconnects, because I'm on a budget doesn't mean I'm not a discerning audiophile.
I can provide specifics as regards my "tweaks" apparently not so with some of the other tweaks I've seen around here. Hey, why don't you impress me with some of your "tweaks." And make sure and use a lot of puffery when you are hyping it up.I take pictures. A picture is worth a thousand words.
Edits: 01/25/11 01/25/11 01/25/11 01/25/11 01/25/11 01/25/11
...and try to be an objective reporter of what I hear. Your assumption that my experience is frivolous is unwarranted.
Hate to tell you this, but I also read many of your posts as somewhat aggressively challenging, not simply asking for clarification. I realize that we cannot read tone into emails accurately. So that suggests that it's our responsibility to be a bit more explicit in our intent and emotional content. (Or you can ignore this - your choice.)
As to CF, you can also tell it works by installing it in your system, doing an informal A/B test if time/space allows, and involving an audiophile friend. I do that and also test it in another audiophile's disparate system. When it works the same way in both systems, and when you can tell when it's there and when it's gone, that's enough for me (and for a lot of the rest of us). In my lower end of hifi system the differences are notable and CF has always been quite positive so far. You don't need a $50K setup to tell.
You're right. We can be fooled into thinking we understand something theoretically, when we're sort of cherry-picking the info, or generalizing too far, etc. And sometimes the theory and/or the measurement available is not sufficient to explain what is a real phenomenon. So we experiment on our own.
Theorizing the negative is not a substitution for safe experimentation for my money. You pays your money and you takes your chances. YMMV has real meaning.
Above is a picture of a scientifically proven way to deal with RFI, it's called a filter. This particular filter is part of an IEC receptacle and the filter is even shielded in it's own little metal box.Any other known (Faraday) RF shield has to virtually enclose the device or object being shielded.
I don't have a lot of spare cash these days (who does) I cannot afford to be wasteful. I'm currently living on about one third the income I had some two years ago. So if I try a new "tweak" it needs to of proven benefit and definitely worth it and not just because someone said so in gloriously mushy terms.
Edits: 01/25/11
You ought to investigate those EMI/RFI filters. Corcom is one of the largest manufacturers (although I understand they've been taken over by some other company) but they make a variety of filters with different amperage ratings and different filter characterists.
In general, the higher the amperage rating, the worse the EMI/RFI suppression. I use the ER series, which has two pi sections, and a claimed 90 dB suppression, IIRC, but I don't use anything larger than a 6 amp rating ( preferring the 3 amp version if possible) and I series them for even further suppression. Those IEC inlet filters do work, but are designed for minimal EMI/RFI suppression.
Stu
I've had a small bookshelf system set up in my single car garage for listening to music when I'm out there working on something. Anyway I only have one usable 120VAC circuit in the garage and pretty much everything I use electrical has to be plugged into that outlet. Well, I've replaced my bookshelf system several times. Currently it's an just an old Radio Shack integrated amp that I bought and repaired, obtained from a thrift store and an inexpensive WalMart DVD player which I use solely for playing CDs. For whatever reason whatever I would buy, set up for listening wouldn't last very long, it kept dying on me. No worries because it is only consumer quality, not high end components. Still though, it happened to me several times and it began to dawn on me that there must be a reason why. It just so happens that the washing machine shares use of this same circuit. No wonder my garage stereos kept dying! So, I installed a 4 gang junction box with additional outlets and inside the box I installed one of those AC line filter for use with only one of the outlets, the outlet that I plug the stereo into. So far so good, no problems with prematurely dying components. Live and learn.
Edits: 01/28/11
I'm semi familiar with their product line and basically everything you told me I already knew. Anyway, they do work even if minimally. The store where I purchased them had an incredible stock of AC line filters. Due to the economy though, the store closed, went out of business. Bummer.The only real way to avoid all RFI and EMI would be rather impractical. We live in a very "noisy" world. I'd really miss my air conditioner, refrigerator (cold beer), cell phone and clean laundry (washing machine). Basically I'd have to live inside a large RF anechoic chamber and wear an aluminum foil hat!
I'd have no problem placing little squares of carbon fiber on all my ICs, but I'm not quite convinced that it would be the correct thing to do.
Edits: 01/26/11
Since the purpose of the carbon is to absorb RFI, a piece of regular carbon fiber,a cut square would basically be tuned to only two frequencies ( taking a page from the stealth technology). That's fine when you know the frequency of the offending signal, but a piece of square carbon fiber may not be the pest application.
Back in '91 I used to shield every semiconductor in my CD player with copper foil and ground the shielding: very tedious and painstaking but it yielded very good results ( inspired by the early Wadia DACs with separate compartments for analog,, digital, power supply stages). Doug Blackburn wrote about this particular tweak ( I had sent him a modified unit for examination) in an early issue of Positive Feedback, although by my request, he did not mention my name.
Digital sources of RFI must certainly include the DAC chips, the servo chips, and, indeed, the laser head mechanism itself. Again it is my contention that we must attack the problems at the source rather than using band aids at the tail end. Certainly a close examination of many CD players and other digital sources reveals that a filter circuit is very often employed at the outputs to cut the RF. This can range from a simple cap, as in the Esoteric series, or a simply first order crossover ( cap and resister) or something more complex ( a series of cap/ resistors forming a pi network ( CJ cd player). Shielding chips often means that compensating circuits may have to be removed in order to preserve tonality.
Recently with the advent of ERS paper, I get even better results than the copper foil shielding. I still use it and often use it to construct crude Faraday cages. Leakage is undoubtedly a bit high but it is certainly very effective, and by simply extending the thin paper over the chassis overlap you get decent coverage.
Also check Max's summary of ferrite use. You can cut a tremendous amount of EMI/RFI feedback on the power grid by simply using ferrites over the power lines of offending appliances. I employ ferrites on everything plugged into the wall with the exception of my audio gear with very good results.
Stu
Stu
I'm all for ferrites. I can't help but notice that every time I buy a new peripheral to use with my computer the supplied connecting cable has a molded in ferrite!
I've been GOOGLEing up EMI and RFI absorption/suppression/rejection/shielding etc. Not really a whole lot out there with regards to using carbon fiber. Metal (various alloys) are still the preferred.
That's very true especially in monitors and printers, which all process video or images.
Carbon fiber is actually used in the ERS paper to serve as a ground plane. Check out the specs at the Stillpoints website. They actually publish the RF attenuation at various frequencies. It is quite impressive.
As a spin off of the stealth technology, I see it being employed more often in consumer products with the Japanese manufacturers jumping on the band wagon. Many are specifically engineered for a set RF frequency. The nickel plated carbon fiber shards which contact the carbon fiber ground plane can be cut to specific lengths to "tune" in specific offending frequencies.
IIRC, that is how the military uses the technology since the radar frequencies of hostile nations are fairly well known. The ERS is a more broadband approach, which makes it well suited for home use where you can get all sorts of offending frequencies.
What is interesting is that in my using copper foil to shield the semiconductors, I suspect the metal actually can reflect some RFI, instead of simply absorbing it. I have experimented with those conductive foam you see used by some shippers in packing static sensitive devices. I gave up on them because the foam does deteriorate ( at least where I live), and I was afraid the conductive foam drifting on a PCB with those micro traces may possibly lead to trouble.
Also I find that placing two ferrites on each power line end is significantly more effective than one. Close to the components helps cut the RF from entering the component, closer to the input plug helps clear your power grid. I was buying ferrites by the hundreds, for a while.
Stu
Then you should do as I did and not take anyone else's word for it, but try it for yourself on your own HDTV system, you'll be the best judge of that. You may see as big a difference as I did, maybe not. I did not expect to see such an improvement, but it exceeded my expectations and I'm really pleased with it. I'm sure everyone would be open to your review, be it good, bad or indifferent.
Edits: 01/26/11 01/26/11
I GOOGLE'd up carbon fiber and RFI/EMI suppression. Also carbon fiber and RAM (Radar Absorbing Materials). I now know more about stealth technology than I ever thought I would. . .
Anyway I came across this information and the very last sentence caught my attention.
"The most common type of EMI occurs in the radio frequency range of the electromagnetic (EM) spectrum, from 10^4 to 10^12 Hertz. This energy can be radiated by computer circuits, radio transmitters, fluorescent lamps, electric motors, overhead power lines, lightning, and many other sources.
Device failures caused by interference – or “noise”– from electromagnetic energy are increasing due to the growing number of products that contain sensitive electronic components. The smaller size and faster operating speeds of these components often make it more challenging to manage EM pollution. Increased device frequencies, applications over 10 GHz are now common, result in proportionally decreased wavelengths that can penetrate very small openings in housings or enclosures."
On the Faraday cages. I wrote earlier that they can have "holes" in them, just as long as the holes or gaps are smaller than the wavelength you wish to shield.
What they're saying here is that at those gigahertz levels the holes are supersmall.
I can't say that what we experience in audio is necessarily within the longer wave lengths, however. The reason I say that is that some of the mineral crystals that work for RFI filtering operate on the gigahertz range too, I believe. And they do work IME (and you may again doubt this if you like) for audible positive impact in our systems for audio.
Did anyone bother to try the metal outlet cover with and without carbon fiber? A before and after comparison? I bet not. Typically one would expect metal alone to be sufficient in shielding against RF. Stacking a piece of carbon fiber on top of a metal plate may be a worthless endeavor. Both are conductors and metal is definitely a denser shield.
So you say you use carbon fiber to absorb. Absorb what from where? In what direction are you trying to absorb in this situation? RF noise from coming in or from going out of the junction box/receptacle? Are you trying to contain RF noise or shut it out? What you are describing is very anisotropic. You're putting the sock on the shoe, the innertube on the tire.
Edits: 01/26/11
Yes, I've tried the metal plate alone, and with CF, and with CF inside and outside. There is a difference. And I'm not the only one to have tried this.
Remember this is not about shielding - you keep going back to that - which essentially is reflecting the energy; it's about absorption (not the best word, but it works) or damping.
Again, you're scepticism, which you found on the theory that you are aware of, won't help you know whether or not this works. You simply need to try it yourself. Otherwise, you will end up sounding very much like a troll.
I'm not accusing you, but just letting you know that you aren't helping any of us with our own experimentation in the current vein you are mining. And it clearly isn't helping you, unless you simply don't want to try this, in which case one wonders why you bother posting.
have deleterious effects on sound anyway? Many AC filters are serial in design and those are not known to be best for audio. Sure, they do deal with RFI and they're great to add to your TV, your computer or your fridge, in order to lower the RF they inject into the system. But for your audio itself, I'd prefer and do use well parallel RFI filtering. And they're easy and cheap to DIY.
Your budget isn't probably different than mine. I like to say that I have champagne ears and a lite beer budget. Moray James called me the Prince of Price IS an Object! So I understand your hesitancy and don't advocate spending just to keep up with the Joneses myself.
If you require something more in the way of proof than the ears of your fellow inmates, you're going to do damn little in the way of tweaks. That's your option, your choice, and nobody can quibble with your choice for yourself.
But denying actively that these things can work is sort of a no-no here, as this is a place dedicated to experimentation and exploration.
CF works for a lot of us and obviously for some high end manufacturers too. You won't know unless you try it. It's a very cheap tweak to use carbon fiber sleeving; not quite so cheap or easy to use sheets or blanks.
I am just funning you. So whatcha building?
I’m currently working on several different projects. What you saw in the previous picture is a VELLEMAN kit amp, solid state. I’m finished with the modules, but I need someone to make me up some nice printed circuit boards for the power supply sections. In my garage I currently have maybe 60 or 70 different woofers, tweeters etc. I have several different sets of loudspeakers under construction. A couple of pairs full of rangers, some medium sized two ways, a five piece set with small full rangers in line arrays, a huge pair of three ways for some real bass and a pair of small sealed isobaric subs. I also have a kit preamp barely started and a DIY turntable to finish with a modified tonearm to do too. Whew!
Edits: 01/25/11 01/25/11
Good conductors reflect radiated noise. Good insulators let it pass through. Carbon fiber is a poor conductor so it converts some of the noise into heat.
The same principle is used to make airplanes with low radar reflectivity.
A material's absorbency at a given frequency depends upon its composition and other things too. Radar absorbing material cannot perfectly absorb radar at any frequency yet alone at all frequencies. Specific compositions do have greater absorbancy at some frequencies than others. There is no one material that is best suited for absorption of all frequencies.
Arbitrarily using a piece of carbon fiber weave may have absolutely no effect at the RF frequencies you may be dealing with. The only way to know for sure if attenuation or absorption is occurring would be to measure the amplitude of the RF noise before and after. The only other possibility would be to have a specification sheet from the manufactured of the carbon weave stating it's usable characteristics or operating frequency range.
It would seem that if the carbon fiber is that good, then you should apply more of it and not just on the front of the receptacle cover, but on the sides and back of the receptacle/junction box too. And while you are at it, all the rest of the wire in your walls all the way from your breaker panel to your junction box especially if your house is wired with ROMEX.Kind of like if KEVLAR is used for making good (which it is) bullet proof vests, then you should make sure your entire vest contains KEVLAR and not just a 2 inch by 3 inch piece directly in front of your heart. Otherwise you still leave other vital organs exposed.
Edits: 01/24/11
You need to think of RF noise in terms of waves extended in space. On conductors, these waves propagate between locations where the impedance changes, and they create standing waves caused by partial reflections at the impedance changes.
A power cord represents such a resonant segment. The impedances of the wall plug/outlet and the inlet connector or termination at the equipment do not in general match the impedance of the cord itself. Further, the boundary conditions require the standing waves to have peak electric fields at the ends.
This means the dissipative material is most effective applied near the ends of the cord. Adding carbon fiber at the wall plate is an elegant way to dampen standing waves on the power cord. One could also apply some carbon fiber to the ends of the cord or the connector bodies, always being careful to keep stray fibers away from the AC conductors. Applying the fiber anywhere else may or may not engage peak electric fields of particular modes, but will not be as effective.
Hadn't thought of it that way, but have noticed that RFI is always present at mechanical connections but then that is where there are impedance changes.....
Thanks,
Stu
The common-mode (also normal-mode in some cases) noise is partially reflected by impedance changes at the connectors. Depending on how bad the mismatch and background noise, any given cable can support standing waves that affect the audio through intermodulation in some other part of the system.
People who build communication satellites understand this. Some few audio cable makers also understand it. Oyaide makes carbon-fiber AC outlet covers to provide damping of the electric field components of standing waves on the power cords.
If RF noise is a problem then it should be dealt with at the source, because RF radiates in all directions not just straight ahead. What is the source and spectral content of the RF noise that you are attempting to suppress?
We're dealing with 60Hz power lines, the impedance of short segments at those frequencies is nil. There isn't much difference in impedance between a power cord and ROMEX at 60Hz unless your power cord is very high end boutique power cord and your ROMEX is extremely long. If your power cord is carrying or radiating RF then so is the ROMEX in the wall.
...that has been dealt with extensively on this forum. We're certainly not going to be able to bring you up to speed in a single thread. Search the archives and be prepared to find a great deal of information, speculation, and of course a lot of misdirected hostility from the resident troll population.
I'm fairly well aware of RF and how to deal with it. Heck, I have a book on RFI from the American Radio Relay League that I got sometime back when Ronald Reagan was President. That is why I use and recommend EMI and RFI filtering in numerous applications, including audio and computer projects that I have built.
I'm not questioning the viability of carbon fiber, only the size and placement. A little piece really isn't enough to get the job done, if at all.
You might be surprised.
I can get very good results simply by using a 2" x 1.5" sleeve on any of my plugs. And you can get results with a tiny piece of sleeve around your RCAs. The amount it takes to cover a switch plate is quite enough to hear a difference.
Yes, you are right that placement does matter.
When you say plugs, which plugs are you referring to? Your AC plugs or RCA plugs? I don't call the "receptacles" in the wall a plug, I call them outlets. A plug is attached to the end of a cord. A plug gets inserted into an outlet or receptacle.Even if you do cover an outlet cover with carbon fiber you still have two rather big holes in the middle of the plate. Big leaks.
You cover your switch plates with carbon weave too? The light switch plates higher up on the wall? Or some other switch plates?
I place ferrites over my RCA cables.
Edits: 01/24/11
Yes, I meant the AC plugs of course.
As to the two holes in the outlet cover, you must misunderstand the theory. The CF is not acting as a shield (and shields can have holes, BTW, as long as they are smaller then the wavelength being shielded against). It's acting as an absorber, so its shape is somewhat less important and coverage is not a critical issue, at least not in the way of a shield.
In my case, I use a double thickness of CF inside my outlet cover and a drilled out 1/2" thick piece on the outside. Then CF sleeves on the AC plug barrels as well. This is very very effective.
By all means, it's not the only method I use to control RFI. It's just a good one to use and is synergistic with many others. I'm told it's possible to overdo CF, but not the way it's easy to overdo ERS cloth, which is actually CF fibers with a nickel coating.
I realize you may be sceptical of this tweak. Consider that some of the highest end AC plugs use CF in the barrels, and some of the higher end power strips/conditioners use it on the covers. There's a good reason for this, and it's not about the looks.
Do you have an online source for genuine carbon fiber sleeves? Or flexible film? Most of the flexible film I saw online was not really carbon fiber, it was just a vinyl film with a carbon fiber look/pattern printed on it.
These guys sort of have it all and at good prices.
Yes, there's a lot of carbon "style" stuff out there! It's bogus for our purposes.
I'm not skeptical of carbon fiber weave whatsoever. I am aware that stealth aircraft are made of carbon fiber etc.
I'm only questioning to the point of getting solid answers. I don't want guesses. When designing circuits, you just don't guess. You don't just use whatever capacitor or resistor you happen to have laying around.
Just for the fun of it, I did however place a small piece of carbon fiber weave in my radar range (microwave oven) just to see what if anything might happen.
Edits: 01/24/11
Radar range, damn you are old ! J/K
I'm not that old!
Edits: 01/31/11
Not that old, I just haven't heard that name in a long time, they sure looked good if you were into chrome though , but since I know what it is I sort of dated myself in the process ..... hehehe
My radarange finally gave up 2 years ago...after 28 years of use! Built so well, it dated itself!
For younger readers, it looked like:
How come you didn't fix it?
I still have my first microwave oven which I purchased back in 1989 and it's still working, but not that well. There are no replacement magnetrons available for it. I actually use to repair microwave ovens, worked in a small appliance shop. It's cool knowing how to fix all you own appliances, saves me a lot of money in the long run.
When you don't know how, it seems much more dangerous. So the same place where I bought it diagnosed it, bad/old magnetron tube. I didn't realize until then about a fee to properly dispose of the parts of microwave ovens. It was a lot heavier to get off the shelf than it was when I was 28 years younger! Restaurant build quality.
Bought another Amana because of good luck even tho not built in US anymore. Now it's 1100 watts compared to around 700-800 (don't remember), so much faster in case you're about to pass out from not eating hot food!
Hey thats a good idea, I have some small strips of the carbon fiber leftover from cutting it down to size to fit the outlet cover. I may just remove a cover and stick a strip in the empty space behind it.
The carbon fibers are sufficiently conductive that you should take care not to allow any to come into contact with hot conductors.
Where did you get the small crystals? I get large beads and chunks.
I got the crystals at the International Gem & Jewelry Show and picked some that were smaller in size. Lots of booths sell small amounts of loose crystals but I found the better value was the larger necklaces of semi-polished crystals. I got three 12 inch necklaces for $20, 2 tourmaline & 1 amethyst, when cut up provides a lot.
The package say "aged bronze cast metal". I don't see the same model online, but they have a similar items in the link. It says it is "cast zinc with a bronze patina, polished and lacquered". The model# I have is 84DVB by Amerelle, it does not have a rope pattern on the front but a 3 step pattern. Its definitely non-magnetic, I tested that. I added the carbon fiber just because other high end outlet covers are using it.
Edits: 01/23/11 01/23/11
The reason why I asked about the covers is because I sometimes do electrical installations and/or equipment repairs, but for whatever reason I have never noticed that type of outlet cover before. I can imagine some of my customers preferring an aged bronzed look/patina over the standard ivory plastic. Also the typical plastic outlet cover doesn't hold up very well either.
I found it elsewhere online, not sure why it doesn't show on the Home Depot website, maybe not all stores carry it. The flat front face made it easy to glue the carbon fiber on.
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