Dedicated line

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.

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.

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!!

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

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