.....Albert, Thanks for your clarification and comments Re: dedicated AC and grounding. My modest system is a worthwhile improvement over standard house wiring. Cheers, Craig |
In response to the comments from Garfish, the ground hum problem is not necessarily related to whole house ground versus the stereo's dedicated ground. Hum as Garfish describes, is often the result of ground planes within the system "talking" to each other, resulting in hum, pickup of radio, etc. This is usually (but not exclusive to) the interconnect shield/ground and/or the speaker wire. The dedicated wiring and grounding system I suggested may or may not resolve this particluar problem. However, it will provide a guaranteed performance increase for the whole system, whether it solves this particular problem or not. If a ground on a individual component must later be "lifted" to remove hum, so be it. Along this line of thought, another really interesting thing to consider about hum and noise, is the ground plane of the floor of your room, and (metal) stands the equipment may be sitting on. I have some of my metal stands (but not all) grounded to the same dedicated star ground plane as the stereo's electrical. This greatly reduces noise and can even completely eliminate CB radio transmissions or the occasional interference from HAM or AM radio. Remember the components in your stereo are designed to amplify very low level signals, so that you may enjoy them through your speakers. Unfortunately, the components do not know which signals are music and which ones are a nusiance. You must remove the ones you don't want, as the system cannot. An additional benefit of addressing this issue, not previously discussed in this posting, is the "gain" in power, dynamics and headroom by doing all this. If noise is being amplified by any or all of your components, they are using up much their energy and headroom to deliver what could be "spent" on the music. Even worse, it is being used up for negative results in with the music. |
Greysquirrel, the reason for three ground rods, is that they are spread over approximately a ten foot area of earth in a large triangle configuration. If the ground potential is higher or lower due to the wetness/dryness of the earth in one particular ground rod's area, the stereo ground still gets the benefit of whatever is the least resistant ground plain. In addition, should anything fail among the three rods, or they begin to corrode after a period of time, you still have a safe margin for your electrical. It is dangerous to have no grounds at all, particularly if you had a component failure. The other good thing about this type of grounding is that the stereo has "priority," in that it does not compete for "space" to discharge or find ground. This is critically important if there is a storm and your house takes a lightning strike (or even a near by strike, such as a power pole). Postings have also spoken about the merit of having more than one dedicated outlet for the stereo. I had not mentioned this before, because it really sounds crazy, but, I have fourteen dedicated outlets just for the stereo alone. EACH one has its own 20 amp breaker, and each has its own star grounding as I described. I added outlets until I could not hear any further changes. For instance, each of my mono amps (main stereo speakers) has its own run, as do every other component, (including all four power supplies at the front end, two are for phono, and two for line stage). Even the surround sound has its own breakers. In addition, the digital (home theater) is on one side of the 220 and the analog is on the other side. I made sure that the house's noisy legs were on the digital side, as it is not as critical to me. (The house has to hook to one or the other or there is no power for it!). The analog side shares the AC drop mostly with circuits in the house that are relatively free of noise (i.e.: incandescent light fixtures.) This may all sound really complicated, but I spent less than six thousand dollars on everything I did to my electrical, and understand, the whole house benefited as well as the target, the stereo. If you put it in perspective, the power supply in an amp or preamp is always discussed as being important. Imagine how important the power supply is for the entire system. And, although it was a large outlay, it is permanent, in that changing components does not diminish my investment. Many of us invest this amount of money in power treatment devices, or high end components, and then loose most of our investment when we sell or trade. This investment in power is a huge benefit for your whole system, and lasts for as long as you live in the house. If you must sell the house later, the amount invested is low compared to the value of a home, and much of the investment may be returned if you sell to anyone who finds the enhanced electrical an inviting addition. |
Hi Greysquirrel; "I wish I understood all I know about this"-- an old, but appropriate saying. I just let the electrician ground as they would for a "set" of dedicated outlets for safety purposes. I can tell you two things: (1) my system is sounding excellent, (2) When I plug my amp into the ded. outlet I get fairly loud "ground loop" hum unless I use a two prong adaptor plug (which I do, but wish I didn't have to). I hope Albert P. addresses your question as I'm interested in it too. Cheers. Craig |
I have 2 20 amp lines run from a submain box that was attached to the main breaker box via conduit. I had an independent ground rod driven for these 2 lines. I think the ground was still tied to the main ground since the two boxes were bonded with the conduit. It was suggested to me in an audio asylum discussion that this arrangement, had created a secondary ground which could endanger my system from lightening strike damage due to the possibility of setting up a loop between the two grounds. If the resistance in the dedicated ground was less the current could feed back through the system. One of the guys provided a technical document supporting the idea. Since i live in an area that has some great thunderstorms (when not suffering from drought as we are now) I moved the ground to the water pipes where the main ground for the house resides and the sound of the system seemed to improve some. The guys in the asylum thought the improvement could have been the result or removing a ground loop that hadn't been at the hum level. |
Forgive me if I'm wrong, but aren't most ground loop problems the result of a difference in potential between grounds, giving rise to "ground loops"? If this is so, then having separate grounds for each outlet would not be wise, right? I can see how having all audio grounded together and separated from other household circuits would be better. Albertporter, this is why you tie the 3 copper bars together, right? |
Korn... I just re-read Albert Porters comments on grounding, and he suggests not to run the ground off the sub-main (the way I did), but ground each hubbell outlet separately. My system now sounds great but Alberts suggestion makes sense but is more trouble to implement. At some point I may have an electrician run a ground wire to each outlet. Albert Porter knows much more about this than me. Craig |
Korn... You can do what you're suggesting, but would only have dedicated power to one hubbell duplex outlet, and your ground would still be the same as for the rest of your house. If you have more than one empty breaker slot, run a line from each one for true dedication, but you still need a separate ground. Sol322 and Whknopp above are right re: grounding and more than one dedicated duplex outlet. Get an electrician, tell him what you want to accomplish and let them do their job-- that's actually what I did. I ended up with a submain panel, ran four dedicated lines off it and attached a dedicated ground to it as described above. You may be able to run several ded. lines from your main breaker box, but I don't know how you'd handle ded. grounding, ie that's where the electrician comes in. Again, good luck. Craig. |
I have recently renovated my house and added a dedicated room. I ran one 20A circuit to two outlets, and then installed two other outlets on another 15A circuit that also runs to other outlets in the house. I included the second circuit expecting to plug in a lamp, record vacuum, etc. After setting up, I have discovered that my amp sounds best when plugged into the dedicated circuit all by itself! This forces my front end onto the common circuit. My recommendation therefore is to run TWO dedicated circuits to your system, one for the amp(s) and one for the front end. |
The use of copper grounding rods only for your system mentioned in the above notes. I haven´t go that far to three separate and so forth but use two it´s worth the effort. What I actually did is I´m feeding my system out of the 220 volts electric range breaker (I use a gas one now) so it was a freebie (nice isn´t it)taking two 110 volts one for the amp and another for front end using dedicated grounding rods. Regards |
Whta exactly do u mean by seperate grounding? |
Korn: Don´t skip the separate grounding!! Not the ideal setup as has been described. Definitely you´ll get improvement over where you are now. |
Guys, thanks for all the responses, i would be lying if i didn't admit that much of what u guys are talking about is going way way over my head. this is my thing. the breaker board or whatever u call it for my house just happens to be in my listening room, can i just not buy a 20 amp fuse, put it in one of the empty slots, run power chord from it to my hospital grade hubbles, and voila, dedicated power line????? |
Thanks Audaibnjad. I remain a sceptic since similar claims have always proven to be false (such as jitter elimination etc.), but I will see if I can get my hands on one to try. |
The PS Audio power plant does a pretty good job at making dedicated power irrevelant (although I must admit that I havn't tried my system with dedicated power to compare it to the power plant). One thing that it does _not_ make irrevalent is a dedicated ground. By US law (I dunno about other countries), it cannot touch the ground. But you can disconnect the unit's ground from the house ground, and use your own instead. It would be very unfortunate to unhook the unit's ground and not have a seperate ground :). Another advantage to the PS audio power plant is that you can increase the cycle rate from 50/60 Hz up to 120 Hz. For my setup, I noticed a slight improvement bumping it up to 85-90Hz, and degridation after that point. Redkiwi: I've only noticed better dynamics with this. Dynamics could be compressed if you, say, used an amp that uses more peak watts than the PS device can produce. For front end gear, the peak current isn't too much higher than normal current, so it would probably be OK. BTW, they do have an export version which puts out 220 or 240V (but it's a bit more expensive than the 117V version). The PS Audio web page is excellent, and Paul McGowan (the designer) is very helpful answering questions. And no, I do not work for PS Audio :). |
Hi Korn. Albertporter has covered the ground arrangement. I have found that the results vary. In one case we found a dramatic reduction in noise, and an improvement that was more significant than the dedicated AC feed. In another case we heard NO difference at all by putting a dedicated earth in. Don't risk getting the directionality wrong or you will be disappointed in the results of your efforts and investment. As Garfish suggests - get enough AC feeder cable to do the job and then just run it from your board through your house or outside (ie. not installed in the walls just yet) and listen to what it does. Then run it the other way. There will be a difference. I have found that one manufacturer's product sounds better when run in the same direction as the writing on the outer of the cable, while anothers' sounds better in the opposite direction to the writing. You have actually got quite a lot of useful information in the above posts if you read them carefully, and all of it gels with my experience. Beware that the end result will cause your system to become a lot more lively and will much more transparently reveal any problems in your components. I am sceptical at Audiowhore's suggestion that the PS Audio makes the AC feed irrelevant. I have not tried a PS Audio unit but the comments I have heard indicate to me that it suffers at least some of the problems of all filters - ie. that it is a trade-off between lower noise floor and compressed dynamics. With a dedicated AC feed and good power cords, I find the benefits of a filter are small and the downsides are unacceptable. When PS Audio have a 240V version I will give it a try. |
Sorry Greysquirrel, but the mainline wire really is directional. Redkiwi suggested it, and so I tried it myself and got the differences in direction as noted in my above post. Albert Porter covered grounding better than I could. My electricians just grounded the sub-main panel that had my four dedicated lines into it, and as I understand it, the closer ther better, but closeness of grounding is not necessary. It's hard to separate the effects of the grounding versus the dedicated lines-- it all works together, ie I did not try them separately, but I got greatly lowered noise floor with the whole system. Re: directionality, I was able to run the main wire outside the wall to check directionality before final installation through the attic, eg I ran wire from the main to submain and then listened to each direction. Good Luck. Craig. |
I´ve found an improvement over bare wire connection (connecting the lines to breakers and main blade switches using cable terminals.(tin plated for less maintenance or pure copper that will require corrosion cleaning). You can use larger than nominal cable awg terminal and make a small loop of the stripped cable, put it inside the terminal and solder it very well. You have this way far more contact area and solder all over the cable surface. I used lead free solder with silver content. The flat surface of the cable terminal providesa very good contact with the bolt and flat metal underneath it. Or simpler maximize the bare wire contact by using the loop trick. Picky I know but it´s been good for me. |
Greysquirrel, regarding your question about "star" and dedicated grounding, the way I got there, was to hire an electrical contractor who had done quite a lot of commercial work, so the wiring I asked for was not unusual, due to his experience with computer rooms and hi tech electronic assembly areas. The "star grounding" method is not strictly legal in our city, as the local electrical code here asks that ALL the grounds be tied together at the electrical box. What I have done, and suggest for you, actually exceeds this code, because it offers safer, multiple grounds. However, because it does not "precisely fit" the rules, is not always easy to hire a professional electrician to get it done. For Star grounding to work, each dedicated run for the audio system must be in PVC, or no conduit at all. The traditional metal outlet housings and metal conduit used in electrical work, automatically tie all the grounds together, back to the electrical panel. DO NOT connect your stereo's dedicated outlets to the main or sub electrical panel. Instead, a SEPARATE ground must be run from each of the stereo's Hubbell computer grade outlets, to the star grounding system. This star system consists of a superior ground plain, that plain requires three copper rods deep in the ground outside of your house (8 ft. or longer, each). This triple ground plain is tied together, and then tied to a single bar under the house. ALL of the stereo's separate TNN wire runs from the individual dedicated circuits tie to that single bar. The purpose of this scheme is so the stereo does not share its ground plane with the remainder of the house's electrical panel. This removes all the ground noise generated from appliances, motors, TV, air conditioning, computers, and other electrical appliances in your home that normally get into your system. The noise floor drops tremendously! If you want to go even farther, have a separate eight gauge copper run pulled from the drop, and run that to a 100 amp 220V panel, and from there you can run Hubbell twist lock 220V outlets to use with high end amps that are capable of running in either 220V or 110V. The Hubbell twist locks can be "split" into two 110V, or run as a single 220V. Barring that, the option of running single Hubbells, as all of us have suggested on this posting, is a superb choice. If you choose to use the method I suggest, and you later add additional dedicated outlets to your stereo, the bar under the house is ready to be tapped into, where the other stereo grounds already reside. This is nice, as it keeps all the "star" grounds in the stereo together and ready for future upgrades. |
note: buy PS Audio 300 and be done with power problems. |
Garfish or Redkiwi, you mentioned a dedicated ground ("3 6 feet copper rods within 10 feet of outlets") for your outlets. I have two dedicated 20A outlets (1 for source and 1 for amp, need a 2nd for amps now that I use mono's). I do not have dedicated grounds. Do you just run the ground for the Romex directly to a dedicated grounding rod? Do you need a separate grounding rod for each dedicated outlet or could 2 amp outlets be connected to the same grounding rod? Does it need to be so close (10 feet) to the dedicated outlets? What kind of improvement can be expected from dedicated grounding rods? BTW, are you really serious about directionality of power wire? That seems hopelessly difficult to test when you have over 50' of wire to pull. Thanks, Greysquirrel. |
Hi Korn and Craig. Craig has covered most of the points well. Note that if you put a dedicated AC in you will have to get good AC cords for ALL of your components. You need the AC cords to provide some common mode rejection, and you may even need to use a filter. Using standard cords with a dedicated AC can be excruciatingly bright and grainy. On the subject of breakers versus fuses - I have found the old style ceramic fuses to sound the best. Craig found the reverse was true, which could be a difference in the power supply, or could relate to Craig using a different style of fuse to the one I am using. Craig is right to emphasise the value of good grounding. |
Hi Korn; I just had a dedicated AC system run to my stereo room. I had an electrician do it because I needed an exterior submain breaker box with four 20 amp breakers put in. The submain was fed by a 50 amp 220 volt breaker from the main breaker panel. I used about 50 feet of 6 gauge power cable. From the submain, there were four separate lines run to four Hubbell outlets. Total cost of this installation was $850. including the $50. for the outlets. As I learned from Redkiwi, a dedicated system will lower the noise floor a lot, but often causes an unwanted brightness that can be difficult to deal with. I ended up putting in Synergistic Research Master Couplers on my amp and pre-amp, and that took care of the brightness. As to your questions: If you have some electrical knowledge and are just running in a single line form a 15 or 20 amp, 110 volt breaker at your main breaker panel you could probably do it yourself, but just routing wire can be difficult. If you plan on multiple outlets as I did, and are coming off a 220 volt 50 amp breaker that needs to be stepped down to 110 volt, you need an electrician-- IMHO. I'd also note that the mainline wire is "directional" as far as music is concerned (I also learned this from Redkiwi), ie it sounds different each direction. So, I tested the wire by listening to it each direction. The first direction produced overly soft, flat, dull, and uninvolving music, while the opposite direction was much better balanced and was the direction of choice. You can only determine this by actually doing the listening tests. Also, Redkiwi (from New Zealand, where they use 240 volt AC) recommended using an old fashioned fuse box rather than breakers. I tried it then listened, and it just didn't sound good, eg music had a prominent mid-bass hump. The advantage of the fuses is that they sound better-- in New Zealand, and that they can be removed and cleaned, whereas breakers can't be cleaned (except for the exterior contacts). But 20 amp breakers only cost $7-8. ot replace. Note: a really important part of a ded. system is a dedicated ground-- I had the electricians drive into the ground three 6 ft. copper rods within 10 ft. of my ded. outlets, and they used a stout grounding cable. Redkiwi, if you read this post, please feel free to comment and/or critique because I'm pretty new to this subject too. Or anyone else also. I mentioned Redkiwi so much because he helped me get my ded. AC system installed, and provided much beneficial information (and support). I should note that my ded. system-- once tweaked, sounds excellent, eg much lower noise floor, blacker blacks, more apparent detail, and dynamics. Try an electrical supply house for bulk power cord. Good Luck Korn. Craig |
