Dedicated line

Following is a summary of the result of tests made on my newly installed dedicated power AC line. Different combinations tested: pre/power/cd player plugged direct or through a power conditioner (PC) to the dedicate line. Best results for my system is cd player and pre-amp plugged direct to dedicate line and power amp through PC to dedicated line. Benefits: reduction of background noise and improved resolution. Very good return on cost / benefit ratio. I ended spending slightly less that $500 (12/3 AWG, ground plate with 6 gauge bare ground wire, 2 Square D breaker, 2 Wattagate outlets and electrician cost), the amount would have been greater if I had use an audio grade electrical line but the cost / benefit ratio would diminish in returns. On a scale of 1 to 5 this is a 3.5 stars upgrade to sound quality and a 4.5 stars upgrade in value for money. If the same amount of $ was spent on upgrading my equipment I don't think I would have achieved an equivalent return. I would certainly recommend this upgrade; perhaps a 10 AWG would yield better results.

The humming noise in my system was SUCCESSFULLY ELIMINATED today!!! Here's the sequence of events. After getting similar results from the ss equipment I called the electrician back to re-check the connections. Here's how the problem was identified. The fuse box is located in the basement and in order to lay the dedicated ground wire he ran the BARE ground wire from the circuit box to the exterior of the house through the ceiling. Inadvertently while pushing the ground wire through it got CROSSED WITH THE CABLE TV WIRE also located between floors in the ceiling! It took a loooong time to come to this conclusion. We conducted several tests and notice that when the dedicated ground line was disconnected the hum disappeared. I then told him that we should lay a new ground line this time burying the ground plate deeper. While he was pulling the ground wire from the ceiling we discovered that it was tangled with the cable line in the ceiling, note there's a cable splitter and that must have been the point of contact, bare ground wire to splitter. My conclusion is that the hum was caused by a ground loop that occurred between the dedicated ground wire and the cable wire. The ground wire is now not touching any other wire and the hum has disappeared. Thank goodness. This problem was driving me crazy. What do I think about the sound? For now I am just RELIEVED and happy that there's no humming noise. I can't objectively comment about the sound because I changed my whole set of tubes in the pre & power before I disconnected my tube equipment just to make sure it was not a run-off tube making the hum. I will put the old set on again and listen in the next few days. Will post my findings on this thread next week. A very BIG THANK YOU to all of you with much appreciation for your kindness and great advice. Best regards.

Thanks for your responses everyone. I am very grateful, I realise that this is truly a great hobby. I have printed all your responses to my questions regarding the problem hum I am experiencing and reading them carefully. I am going to plug my solidstate (ss) system to do some testing. I don't want to do this on my tube equipment for fear of damaging them as I would have to switch on/off many times to try some of the suggestions. Sol322, the dedicated line was installed by a professional. Pending the outcome of the ss test, I will get him back for any other required adjustments, as this is definitely NOT my area of expertise. Here are more details on how I connected my equipment. TO DEDICATED LINE- 2 scenarios that caused the hum to occur 1) ALL equipment through a power conditioner to one outlet 2) ALL equipment directly to the newly installed dedicated outlets. I have pre/power/CD so I used only 3 outlets. TO COMMON LINE- Same connection as above scenarios but this time to common outlets. Note my common line has no ground connection. Result is NO HJM! I will post ss results, sometime tomorrow, July 11. Many thanks again to all. Best regards.

Johnmhuntbch, What did you do at Ga. Power. I myself was at FP&L. for 15 years. Would like to hear from you. Thanks, Skip.

There is a lot of information on tweeking power and the your listening room on the Vansevers.com web site.

Audioquest AC-12 Try HCMaudio Regards

Glim: Got your message.... Can think of two possible sources: Ground loop Incorrect connection polarity at wall plates. For testing purposes "float" the ground in your front end components to see if the hum disappears. If it does you have a ground loop problem connections for both front end and amp should be at the same potential. (Check safety on local code) If above doesn't show improvement check that polarity connections are OK, i.e. that the lowest potential is obtained at the components chassis. . Suggest to try a cheater plug for this if you reverse connection polarity and noise is gone that's the source keep in mind that you need to keep ground connection though for this test or mixed results between reverse polarity influences and ground loops will be obtained (REMEMBER SAFETY FIRST KNOW WHAT YOU ARE DOING OR HIRE SOMEONE THAT DOES). If you have a power conditioner where you have hooked all your front ends by lifting ground for testing could also provide the answer. (Cheater plug) If capacity allows and for testing purposes you can plug the amp to the power line conditioner and see what it does for you. Don't over power the PLC but try to see if noise lowers without major power demands from amp- Need more details to help out. Could you be more specific on the connections? Amp to wall dedicated wall outlet, and front components to power line conditioner? Regards

What I am going to say here is based on 30+ years of experience with major manufacturers (GE, SqD) and a utility (Ga Power)in the electrical products market, from the high voltage switchgear utilized by the utility all the way down to the 15 amp circuit receptical (outlet) in a residence. During this entire time I have maintained a strong interest in audio, although I have only recently invested in big buck gear. 1) I never heard ac noise in my audio system until I had purchased the big buck gear that revealed the power quality for what is is! 2) The dedicated circuits and isolated grounding that I am using is effective, up to a point, in reducing the problem, as follows: a) from my listening position, I have dead silence 98% of the time. The 2% that I don't is due to feedback via the common (neutral 'white wire') from my PC, a dimmer, a fluorescent lamp, & sometimes the refrigerator, all inside my own house & not the utilities problem. b)for this 98% 'Quiet tTime', if I get down on my hands & knees & put my ear 1 to 3 inches from the bass drivers, I can hear the 60hz 'thrum-thrum-thrum'. This is when my tube power amps are on, regardless of preamp on or off & regardless of the amps being fed via preamp or direct from the CD source. The 'thrum' is less when using cheaters to eliminate the ground all together than without them, but either way, to hear it, requires being on hands & knees very close to the bass drivers. c)none of the AC power devices I've tried have done anything to reduce this 60 hz 'thrum'. Exotic power cords don't either, although they seemed to do more on the non- dedicated circuits I had before. I have delt with wiring devices, from the 29 cent outlet variety through the most expensive mass produced ones by Hubbell, P&S, Leviton, Bryant, etc, & have heard no difference until the point where the cheap ones lose their spring tension & cannot hold a plug tightly. I use $8.50 P&S isolated ground industrial grade 15 amp recepticals fed by # 12 20 amp solid house wire, individual wires, not romex, in a steel conduit. d)I have not tried the PS300/600 yet, as the 'thrum' I'm describing is of such low level it is completly hidden by any level audio signal. However, the product makes technical sense as it delivers balanced ac power to our North American 120 volt homes. 240 volts is balanced, 120 is unbalanced, which allows the neutral feedback I mentioned as the source of my 2% problem. I would love to hear from some of our European readers about line noise in their 240 volt systems - I bet it is far below the audible level - but I don't know from experience. If it is, we can all have 240 volt dedicated lines installed & buy 240 volt gear! 3)The 8' ground rod outside my listening room that I use to ground my dedicated circuit is not strictly in accordance with the National Electrical Code, which insists that the ground path go directly back to the service entrance box. There is a safety reason for this NEC requirement, in that if you somehow manage to get hold of your service entrance ground at the same time you have a hold of your dedicated ground, you can receive a shock from the difference in ground potential, so if you do this at home, know what you are doing! I'm not recommending it to anyone else just because I do it, remember I have an electrical background. 4)Anyone know if the PS300/600 solves this problem? Any other solution? Thanks!!

Hi, My own experience: I first installed a 12 gauge dedicated ground, going to an 8' copper-plated brass rod or post driven all the way into the ground, complementing a dedicated line from the main breaker panel. (Of course its ground own was removed when the dedicated one went in.) I heard an improvement, but not major. Then I changed to a 10 gauge ground wire, all else the same, and DID hear a major improvement. I almost wish I'd gone all the way to 8 gauge. Please consult stnemo@starpower.net on this, though. He was the one who told me to use at least 10 gauge. He's the Stealth cable designer/manufacturer, and could supply a great power cord if that's what's called for. affordable too. But he could also tell you whether it's necessary. His power cords made a big difference in my system, BTW. But then so did his interconnects, digital cables and speaker cables. Along with the dedicated grounding, you might want to give them a 30-day money-back guarantee try.

Yesterday, I installed 2 dedicated lines. Unfortunately, I had no success obtaining info on an audio powerline. Being in Canada, I needed a powerline that had UL and CSA approval due to insurance purposes. Home Depot came to the rescue. I ended with a Carol 12/3 CSA and UL approved electrical line (2x 22ft run), two 20amp Square D breaker (1 for each line), 1 flat ground plate and a 6-gauge ground line (20ft unshielded run from circuit breaker box to ground plate buried 24inches deep), both ground from dedicated lines were connected to the ground plate. In addition, I used 2 wattagate outlets. Everything was brand new. After connecting my equipment to the dedicated lines I notice that there was a hum/buzz emitting through the speakers. It was not pronounced when music was being played but very noticeable when the equipment was at idle. I cross checked by turning off my input source and putting the volume at maximum setting; sure enough the hum was louder. Next I set my pre-amp to mute, there was no hum. Other connection scenarios yielded similar results; through powerline conditioner or direct from my powersnakes to the outlets. Just to ensure it was not my equipment (never had this problem so far, I use tubes and I think they are in fairly good shape) my final check was to plug everything to the generic lines/outlets (shared power outlets WITHOUT ground connection). The hum DISAPPEARED! My second issue is when a florescent lamp connected to a common line/outlet is turned on and my system is affected with a loud click from the speakers. It's louder turning it on then off. I test with a normal light bulb lamp and there were no interferences. I thought at a dedicated line being isolated will not be affected by other outlets. With this hum, presumably ground feedback, I can't tell if the background noise was eliminated. What am I doing incorrectly? Appreciate any help and advice you may have to get rid of the problem. Many thanks.

Thanks very much, Sol322 that's what I will do and will perhaps post the results on this thread in a couple of weeks. Does anyone know where I can get AudioQuest AC-12?

Glim: I also have separate ground for my 2 12AWG 110 lines for my system: one is for the amp the other for front end. Breakers are 20 amp. I´m considering to go heavier in the amp line though... Regards

Thanks guys! J_k, I checked the Audioquest page: http://www.audioquest.com/theory/theory9.html#power and there were a couple of paragraphs on AC-12, sounds good. "AudioQuest AC-12 is a 12 awg x 3 cable using four separate solid18 awg OFHC conductors for hot, four for neutral and a 12 awg stranded conductor for earth. AC 12 is surprisingly flexible considering the serious ingredients inside. Brute force, superior materials and design, plus a powerful RF Stopper, explain why this cable works so very well. UL and CSA." Wonder what's the cost? JPS also had a page on Power AC 8AWG Home AC wire. Before they removed the price on page it was $30 per/ft. with a minimum 100ft order. This is over my budget of $1,000 for the project. Since I am not spending on the power conditioners I figure this would be alright if I am not moving house before 5 years! Sol322 I agree, I think dedicated lines help compliment powercords if they do the job of helping shield against RF. Thanks for reminding me about the breakers, I will have brand new breakers. With an investment like this I want to do it right. But I am still thinking about the grounding source that Johnmhuntbch mentioned. If I run the ground from the circuit box to outlet it would be making full use of a cable like AudioQuest. If a separate ground line is run to the OUTLET then essentially the ground on the AC-12 would be "wasted" (although the cable housing would still shield the background noise)….hmmm. A separate ground sounds sensible, as it will be isolated from the interference from other outlets. Any thoughts?

Glim: Go for the dedicated line and grounding if you really wan´t to get the most out of youre gear!!!!! Those people told you not a difference are deaf and don´t know what they are talking about Don´t overlook the breaker if it´s old will add resistance to current flow.....Remember every contact point should be checked for the best possible connection. Good luck.

Check out the Audioquest AC-12 for house wiring cable....

Johnmhuntbch, this is excellent advice, thank you! It's very possible that my option could an "audio grade" power cable. Any brand suggestion? This being for a power line about 40ft. perhaps a good value for money model would make sense. I am giving up power conditioners after I have the dedicated line and will have Powersnakes plugged directly to Wattagate outlets on the dedicated line. A fellow in another posting mentioned, "Isolation grounding means that a different wire type is used to carry the back-box ground to another grounding point on the breaker box". But in your case the isolated ground you installed has a separate ground wire from the new receptacle (outlet) to the ground rod and NOT from the dedicated circuit in panel box to the ground rod. Do I understand it right? I am meeting a recommended electrician tomorrow who's suppose to be in tune with wiring of audio equipment. A couple I spoke to (from the Yellow pages listing) advised me that the difference of a dedicated ac line on audio would be indistinguishable to the human ear! Many thanks again for sharing your experiences.

#12 is good for 20 amps, plenty of amps for most audio gear. Standard house wiring is insulated fine for safety but has zero shelding for EMI or RFI, which is why the big buck power cable guys can draw such a following. If you have a very short run from your service entrance point, or very deep pockets, you could run 'audio grade' power cable all the way to gain EMI/RFI shielding. I recently had a dedicated line installed as well as an isolated ground. I was able to install the isolated ground myself by driving an 8' copper ground rod into the ground outside my listening room, changing the recepticals to the isolated ground variety, and running a seperate ground wire from the new receptical to the ground rod. This made an incredible improvement in depth, clarity & background silence, but there was still some A/C 60hz noise, so I had an electrician install a dedicated 20 amp circuit (with regular house wire, but in a metal conduit), leaving the isolated ground in place. Now the ONLY sounds between cuts are the sounds made by the tubes & transformers in my Cary power amps. To hear this, I have to crank the power up past 12 noon & kneel on all 4's in front of my speakers. From the listening position there is dead silence. This is with or with out my Monster HTS2000 in the line, reducing the HTS2000 to surge protection only as there is no noise left to clean up. The isolated grounding cost me about $30 & some sweat. The dedicated circuit cost $300 for the labor & materials. Hope this helps.