AudioCircle
Audio/Video Gear and Systems => Power Conditioning => Topic started by: deadhead on 4 Oct 2020, 12:08 pm
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Ladies and gents,
I need to employ the collective wisdom of the board to get to the bottom of an issue that is driving me up a wall. I live in NJ and I have a problem with transformer hum. I have 2 separate pieces of equipment that are affected, so much so that my system is hard to enjoy. My Don Sachs Kootenay amp and the power supply for my Modrwright/Oppo 205 both have an audible noise that's constant.
I have read every article I could find about isolating the outlets etc. The problem in a modern home is I still need to live there and so does the rest of my family. What I'm trying the figure out is who is most qualified the figure out what the cause is and will that person have a solution. My first thought is to hire an electrical engineer and be done with it. I'm not interested in trial and error as I have purchased some power conditioning that has done nothing.
Any help would be greatly appreciated.
Jeff
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If what you hear is a mechanical hum, chances are you may have DC on the AC line. You might want to try one of AVA's humdinger devices as an easy test.
https://www.audiocircle.com/index.php?topic=114316.0
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If what you hear is a mechanical hum, chances are you may have DC on the AC line. You might want to try one of AVA's humdinger devices as an easy test.
https://www.audiocircle.com/index.php?topic=114316.0
I did that. No change.
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Recommend a good electrician.
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First get a 'Kill-a-Watt' meter. Measure the voltage at many different wall outlets thru out the home. With different appliances and HVAC both on & off.
Expect to differences under 5 Volts. Also note the highest line voltage.
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One of these might provide some information on the situation. I had an odd situation where everything I plugged into an outlet worked fine, except for a ipad charger. I checked it with one of these and lo and behold I found the outlet was not grounded properly.
Worst case is it gives you something to do while you wait for an electrician.
https://www.amazon.com/electrical-outlet-tester/s?k=electrical+outlet+tester
BTW if you move the equipment to different circuits on the house, does the problem remain the same?
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Yes, check your voltage, if it is getting close to 125VAC it can make some transformers hum and others don't.
Chris H.
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Is everything plugged into the same power outlet? If not, is it possible that some of your gear is connected to the opposite leg of the breaker panel?
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One of these might provide some information on the situation. I had an odd situation where everything I plugged into an outlet worked fine, except for a ipad charger. I checked it with one of these and lo and behold I found the outlet was not grounded properly.
Worst case is it gives you something to do while you wait for an electrician.
https://www.amazon.com/electrical-outlet-tester/s?k=electrical+outlet+tester
BTW if you move the equipment to different circuits on the house, does the problem remain the same?
That's the next step. The thing is the room the equipment is in is designated for just that so either way I'm forced to deal with it. If it was happening to one transformer I might be able to point to the equipment but since it's more than one (and and Odyssey SS amp as well) it's something in the house.
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Is everything plugged into the same power outlet? If not, is it possible that some of your gear is connected to the opposite leg of the breaker panel?
I've switched outlets in the room from the dedicated 4 gang box to a different outlet with the same results. Also changed out the hum dinger for a Zero Surge unit as well and a Richard Grey's conditioner. It seems voltage may be the culprit but I'm not qualified to diagnose. My experience with local electricians hasn't been stellar. Most seem to be able to do the basic stuff but when it comes to things like this I thought I'd need someone with a higher level of expertise.
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Do you have a multimeter ? If so measure the incoming AC voltage. A Circuit checker as well will tell you if outlet is wired correctly or not. Grounding might tight at outlet or just not connected. I would turn off outlet from panel remove screws holding outlet and inspect to see if wires are tight and correct. Have you tried cheater plugs to see if ground issue ?
charles
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Do you have a multimeter ? If so measure the incoming AC voltage. A Circuit checker as well will tell you if outlet is wired correctly or not. Grounding might tight at outlet or just not connected. I would turn off outlet from panel remove screws holding outlet and inspect to see if wires are tight and correct. Have you tried cheater plugs to see if ground issue ?
charles
Charles,
Now you're above my pay grade. Cheater plugs? Here's my philosophy, focus on making money and pay the professionals to deal with what they're good at. It's not that I don't want to learn, my dance card is so full right now I barely have time to listen to music. If I do find there's a wiring issue I still need to bring someone in to deal with it so I thought I'd try to find the right person from the jump. I'm trying to figure out who would be most qualified to give me the correct diagnosis.
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Call the power company. It could be an issue outside your home. If it's inside your home there will be a fee, but they do have a lot of expertise and if it's outside your home they will fix it for free.
A friend was struggling with some issues and it ended up being a corroded neutral line from box to pole. Fixed for free.
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Charles,
Now you're above my pay grade. Cheater plugs? Here's my philosophy, focus on making money and pay the professionals to deal with what they're good at. It's not that I don't want to learn, my dance card is so full right now I barely have time to listen to music. If I do find there's a wiring issue I still need to bring someone in to deal with it so I thought I'd try to find the right person from the jump. I'm trying to figure out who would be most qualified to give me the correct diagnosis.
Then by all means contact power company first.
charles
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So if it does turn out to be a voltage issue, from what I'm hearing I should start with the utility and work my way into the house using a qualified electrician?
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......It seems voltage may be the culprit but I'm not qualified to diagnose. My experience with local electricians hasn't been stellar. Most seem to be able to do the basic stuff but when it comes to things like this I thought I'd need someone with a higher level of expertise.
A regular licensed electrician isn't likely to have any idea why your power supply transformer(s) are buzzing/humming, or what to do to stop it. He/she would be able to inspect the general installation and functionality of the system, and also measure the voltage, but that's pretty much it. Similarly, your power company isn't going to be empathetic as long as the power meets whatever their normal swings in voltage are. I've had equipment with toroidal transformers that have done this over the years, but intermittently.
Consider reaching out to members of this forum or others you use for someone who has a PS Audio regenerator and lives near you and would be willing to let you try it. Power conditioning won't prevent this issue, but the regenerator will. Worst case, pick one up on the 30 day evaluation. Probably money better spent than running a new panel with separate grounds from the main panel and dedicated lines to your equipment, only to find out there's still mechanical hum in your equipment.
The power grid isn't designed for audiophiles, and shouldn't be. It's unbelievably reliable and our houses rarely catch fire because of electrical equipment (UL approved) in our homes being damaged by the grid.
There's no argument about the grid being noisy, and dirty, it is. I think a point of service component like the regenerator would be a reasonable approach for your situation, compared to getting in the weeds reinventing the wheel of electricity in your home. :D
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Rusty,
Thank you. My first instinct was to avoid an electrician. I know what they're good at and it's not this. I just looked at the PS audio site. It's probably worth a phone call to see what they think. I called NJPAC, a concert hall in Newark to see if I could get someone technical on the phone and see who they work with when issues arise. Covid has made it difficult to find anyone at home. Maybe some local recording studios would have an idea.
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Power company will usually come out for free. It's not unusual to have issues with power delivery that can be fixed for free as it is often in their equipment outside the house. I don't think you'll lose anything by having them come out to inspect.
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Electrical Engineer here. I have extensive experience with power related issues, albeit in industrial environments. Just to be clear I assume you are saying the humming is coming from your electronic devices and not your speakers. I have a few suggestions you can try.
1. Take your suspect devices to a friends house or work and see if the devices hum there. If the hum remains the problem is probably in your gear and not with the power in your house. If the hum goes way then there is most likely a problem with the power in your house.
2. Find somebody who is qualified (like an electrician) and owns a DC voltmeter that can be inserted into your power outlet (PLEASE BE CAREFUL!) and see if DC voltage if present. If DC voltage is present then you have some digging to do.
3. If you have a DC voltage problem, have your electrician go to your main breaker panel. Open panel and measure for DC voltage between each leg and neutral (I assume you have 240/120 VAC service). If DC voltage is present at the main breaker panel then turn all the breakers off (only if you can turn everything in the house off without endangering anybody). If DC voltage remains then the DC offset is coming from the secondary windings of your utility transformer (which is probably shared with neighbors). At this point you should get your utility provider involved. The problem may be coming from a neighbor you share the transformer with. If DC voltage is never present in your main breaker panel and you are measuring DC voltage at an outlet then the problem lies within your house.
4. Harmonic distortion problem. The voltage waveform in your house should be a pure sinewave. If it is a distorted sinewave you have to figure out why. THE MOST COMMON CULPRIT ARE LIGHT DIMMERS. If you have light dimmers get rid of them or keep those lights off or undimmed while you listen to music. Devices with switch mode power supplies (like computers, tvs) can also pollute your power. If possible try to run a dedicated (not shared with any thing else) power circuit to your listening room. Some electricians will have power analyzers that can measure harmonic distortion.
5. If you dont want to try 2,3,or 4 try an electrostatically shielded isolation transformer such as Trip Lite IS1000 - good for 1000 watts. You can try the IS1500 or IS1800 if you need more capacity. Available and returnable on Amazon. Plug the transformer into your wall outlet and plug your audio gear into the outlets built into the transformer. The transformer has primary and secondary windings magnetically connected, but not electrically so it cannot pass DC voltage through it. The electrostatic shield also collects and filters electrical noise. Beware that isolation transformers themselves hum a bit and that may be a problem for you. I use one of these devices located next to my equipment rack and cannot hear it from my listening position. Some audiophiles will tell you not to use isolation transformers as they can impede or choke current flow to devices that draw a lot of power (mainly amplifiers). I personally dont see this as a problem for my gear but YMMV.
6. Somebody recommended a PS Audio power regenerator. I personally have not tried one of these, but the science is sound.
For the record I don't work for a company whose products I mentioned. Sorry for writing a book, it's the way our engineering minds work.
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The book you wrote helped. Thank you for your thoughtful reply. I just got off the phone with PS audio and placed an order for a Power Plant 15. The gentleman I spoke with was convinced this would resolve the issue I'm having as well as improve the dynamics of my system. They offer a no risk trial so there's not much to think about away from the money spent if it works..
I want to thank everyone who responded for their generosity in sharing their knowledge and experience. It was all factored into my decision. I'll report back once the new equipment arrives.
Jeff
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I am in alignment with DaveC113 and DWG. I think you should identify the source of the problem first (utility or home) then solve. I was going to suggest a whole house isolation transformer if it is the utility but it might be a bad a pole pig. The PP 15 may solve the issue but if the incoming power is a problem then I would be concerned it would eventually get worse and cause problems with the PP 15.
Just some thoughts.
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How did the PS Audio Power Plat 15 workout for you, did it solve the problem?
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If you leave the sheet music out in front of the gear, they might learn the words and stop the humming.
Or do what DWG said. Cheaper to have an electrician come out and check you out than trash your gear.
And those ISO trannies are not wildly expensive - Ebay to try one perhaps.
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How did the PS Audio Power Plat 15 workout for you, did it solve the problem?
Haven't heard back from the OP about success eliminating the hum. There was another similar thread running recently with someone having the same issue and finding a resolution.
https://www.audiocircle.com/index.php?topic=172903.0
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You may want to try one of these from van alstine - HUMDINGER DC LINE BLOCKER. Good luck!