Bob- I did not post any misinformation. Twisting the AC wires did not get rid of noise that was already there that I could see. We did this when I was in school years ago and
did not see a noticable difference.
Could this help eliminate further EMI and RFI? Maybe I don't know. I'll be the first to admit I don't know it all, hence the reason for my question at the end. |
Bob, this subject of not feeding power amps through power conditioners is questionable. I figure the conditioner must be properly designed to start with.
I have a Tice A/V Solo and it has separate filtering for power amps. For larger power amps George Tice has a high current model devoted to amps exclusively. I am using a high current(though only 50W) dual mono amp with 6dB headroom and the A/V Solo does improve the sound without choking dynamics. The amp sounds better through the Tice. Bass is tighter and highs are smoother on transients. Noise floor improves. Now if someone's using one of those Monster Cable power strips or similar then that's a whole different story.
I have been reading in the TNT Audio forums that in European countries some apartment buildings each apartment is being installed power filters in their electrical wiring. Under such circumstances shielding the dedicated line would be important to keep the filtered current from getting any more noise. If I were to set up a dedicated line I would definetely place some filtration at the beginning and shield the line. That's why I asked about the twisting in the beginning. |
Not everyone with a dedicated line uses AC line conditioning, expecially when sourcing a power amp. Ask Mike VansEvers if you must understand the physics - I trust him unquestionably & certainly won't be arguing so help yourself. Whatever the electromagnetic phenomenon, this is what he recommends for a quieter dedicated AC line & for connection into a line conditioner. It works too. If you don't want to do this then don't, it's your loss, but don't go posting misinformation that this is ineffective just because you don't understand.
There are many things that we do but don't completely understand all of the reasons why; there's really no need to. Another example: it's no problem driving an automobile even if you don't understand everything that's going on under the hood. |
If you run it through a power conditioner, which all us Audiophiles do...right??, twisting the wire etc..should be a moot point.
I also don't see the point in twisting the hot, nuetral and ground together other than to keep them together. This is not a data cable and twisting it will not eliminate the hash noise off the AC or do anything to correct the PF.
Perhaps there is another reason for doing it? |
So if the twist of the wires is in the same direction then there's no common mode rejection, correct? Why twist them, then?
I'm not being argumentative here, just want to find the facts. |
No there are not two grounds; the ground wire is simply twisted in the same spiral along with the hot & neutral conductors; all three conductors are contained in the same twist. That's the way that Mike VansEvers told me to do this; I didn't question or ask all about his reasoning, as he only mentioned this as an aside during a conversation regarding his AC cord products. |
Bob Bundus, there's something I don't understand about the homemade power cable. From what I understand the (+) and the (-) are twisted so that the interference cancels itself out. Now what is to be done with the ground cord? Use two wires and twist them separately too? |
Thermoplastic High Heat Nylon (insulation)
KP |
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Infwgf, do you know the part number of the 10awg shielded belden cable and where can I find it? Is it available on website?
Thanks
Tran |
The best dedicated circuit you can run is, By using 10awg shielded belden cable. Me and my friend wired up his home theater with romex orginally and though that it could use some improvement. So we shopped around and found this
10 awg. Belden cable that had high purity copper and it was shielded. It already had a jacket although we still had to run it in Flex conduit because of code . This is the single best upgrade anyone can do to there system. It elevated the whole system by a wide margin. |
To follow up....If your using metal conduit and boxes for your new circuits make sure that your electrician DOES NOT bond your new outlets to the boxes via any jumper wire.Doing so will defeat the isolated ground on your hospital grade plugs.The goal is to keep your audio circuits ground path separate from your house wiring.The reason being is if your house uses metal boxes with bonded outlets ,as many modern homes do,your metal conduit via it's connection to your bonded panel enclosure becomes part of that ground path allowing stray voltages to make there way into your audio circuits.One advantage of the metal conduit in this set up is that it acts like a shield in many of the better power cords where the shield wire is connected at the load end ( or your panel in this case) only.Same principle at work here...... |
Bundus is right on about wire choice.I've done exactly as he describes with excellent results.The electrician should know that a separate ground is against code.The reason it's not a good idea is with two ground paths any overvoltage can find it's way back through your equip.isolated ground.Also two ground potentials is the biggest source of ground loop hums ect.Unless you had a separate service feed from the utility transformer and panel grounded to a new rod for your audio circuits the best way to handle your grounding is to suplement your existing service ground with an 8' electrode driven at least 6' from any existing rod and connected in parallel not series to the same lug on the grounding/neutral bar in your panel.Have the electrician connect your new circuits isolated ground wire as close as possible to this point and you will have a star grounded low impedence ground path.This is what I did and the noise floor is much lower....Good luck! |
30A wire capacity to 20A outlet is fine if the conductors will fit the outlet screws. I didn't go any larger than #10awg because any larger is a bear to work with (& won't fit into the outlet anyway). Wiring code advises against 2nd seperate ground rod (something about potential ground currents causing damage if you receive a direct lightning hit) but many people do run it separately anyway with good results. Others advise to make a connection from the isolated ground rod back to the original rod (to eliminate the lightning potential scenario) however I don't know if that affects / degrades the isolated grounding advantages; I suspect that it might not be a problem. I would think that the two rods being in close proximity would reduce the hazard potential, if in fact that is actually a real world concern? It sounds like you might actually have an enlightened electrical guy there - his idea sounds reasonable to me anyway. |
Hi,
Can I run 30A line to a receptacle 20A? Asking this because the cost for 30A and 20A is the same, and I already had Wattgate 20A. Moreover,I can use 30A for a bigger amp in the future.
Some suggest use second ground rod for dedicated lines, others say that tie the dedicated ground to the main ground rod, and then improve the main ground rod. Which way should I use? Electrician suggest a second ground rod for dedicated line. However, the distance from the first and second rod is just 2' apart. Are they too close?
Thanks
Tran |
Worldcup, I've started looking into the same issue,heres a couple a links from here:
http://forum.audiogon.com/cgi-bin/fr.pl?fcabl&987256243&read&keyw&zz10=gauge
http://forum.audiogon.com/cgi-bin/fr.pl?ymisc&1009817715&read&keyw&zz10=gauge
Please post anything of interest you come across on this subject.
KP |
There are numerous upgrade wires available for dedicated lines which I've read about (try to find those archive threads; Kimber is one definite source) but I used #10 solid copper THHN. Mike VansEvers gave me this idea which has worked so well that I'm just amazed.
You make up a bundle of black white & green conductors, all aligned with the printing running in the same direction. Fasten the ends of the bundle with electrical tape, clamp one end in a vice & put the other end in your variable speed 3/8" drill chuck. Slowly spin the bundle to wind it up like a spring; when you release power it will uncoil considerably. Then exchange ends & finish the twist. This twisted configuration is similar to the way many upgrade AC cords are made, it cancels stray magnetic fields outside the conductors. Lay the bundle in across the floor & connect it temporarily, then listen for awhile to test & determine which direction sounds better than the other direction. When you install in conduit or Greenfield, then burnish the exposed wire ends nice & shiny with crocus cloth (or an ink eraser in a pinch)& clean them thoroughly with Kontact, etc. Also shine up & Kontact clean the male prongs of your AC cords. Use a high grade outlet; FIM etc. Also consider isolated grounding. Your electrician won't understand any of this "audio nonsense" & will probably try to tell you that it makes no difference, but believe me it absolutely does. If you can get him to install a small fusebox & use a ceramic fuse (vs. glass) that will sound better than any circuit breaker. The newer plastic fuses seem to be OK too. He'll say you're insane but hey you're the paying customer so get it done the way that YOU want it done. Also polish & clean the fuse itself & any elecrical contacting surfaces in the distribution box.
Long ago I posted several times on this question, but the forum archives appear to be truncated as I can't locate them anymore. Shame that it is lost as there was a lot of good info in those old posts, & not just mine either. |
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use the search function here and you will find numerous recommendations a lot faster. Type "dedicated lines" |
