electrical question - way off topic but hoping someone can help

[viaspiaggia]

Was working all day, then had to run my kid to the doctor this afternoon. When I returned there was a high frequency buzzing, 4k, 8k, 12k, almost like a fluorescent bulb. Seemed to be coming from the power strip / surge protector that my speakers are on. Then seemed to be coming from another power strip on a different circuit that powers my monitors and usb hub. Went to the machine room and found the power supply on my computer chiming in on the same tone.

I've tried to narrow down the culprit but any single device makes the buzzing even when it's the only thing plugged in. Did I suddenly get this noise on my house's power this afternoon?

I know a buzzing OUTLET can be bad wiring that can be super-bad-news, but this is only when the certain things are booted up or turned on, must be one of the elements, but why is it spreading to the others?

The only thing I haven't had completely unplugged (though it was turned off for some tests) is the Monster Power power conditioner that all my audio gear runs through; I'll test that when I shut down completely tonight.

I'll pick up an EZ outlet tester tomorrow to see if I have a problem on an outlet somewhere, and if I need to just call an electrician I will, but thought I'd see if there's something I'm missing.

THANKS!

[viaspiaggia]

aaaand it stopped as I was shutting down my computer for some more testing. Currently NOT buzzing with everything plugged in and running.

Still going to pick up that tester to make sure everything is hunky-dory, but any other troubleshooting tips are greatly appreciated.

[minister]

It could be any number of things as these situations are very complex. I occasionally get a squealing in my lights, and then it goes away. In your situation, it could be the MOV (metal oxide varistor) in your surge protecting power strip (if it has one); could be a bad power strip; your Monster unit getting flakey; could be the computer power supply started generating harmonics; could be something else in the house like a hair dryer; laser printer; refrigerator; iPhone; electric oven; arc welder at your neighbor's house; air conditioner; static; temporary anomaly from the power company; Jehova's Witnesses; door to door salesmen; the milk man; Harmonic Convergence.......

An electrician will check basic wiring and code compliance. Noise issues they rarely know how to chase or deal with.

If it went away, I would forget about it. If it happens again, I would isolate things one by one. Try plugging things into different circuits, same circuits.

Generally speaking, but not in all cases, keeping things on the same circuit is better then crossing circuits.

[John_Toolbox]

Was working all day, then had to run my kid to the doctor this afternoon. When I returned there was a high frequency buzzing, 4k, 8k, 12k, almost like a fluorescent bulb. Seemed to be coming from the power strip / surge protector that my speakers are on. Then seemed to be coming from another power strip on a different circuit that powers my monitors and usb hub. Went to the machine room and found the power supply on my computer chiming in on the same tone.

I've tried to narrow down the culprit but any single device makes the buzzing even when it's the only thing plugged in. Did I suddenly get this noise on my house's power this afternoon?

I know a buzzing OUTLET can be bad wiring that can be super-bad-news, but this is only when the certain things are booted up or turned on, must be one of the elements, but why is it spreading to the others?

The only thing I haven't had completely unplugged (though it was turned off for some tests) is the Monster Power power conditioner that all my audio gear runs through; I'll test that when I shut down completely tonight.

I'll pick up an EZ outlet tester tomorrow to see if I have a problem on an outlet somewhere, and if I need to just call an electrician I will, but thought I'd see if there's something I'm missing.

THANKS!

Sounds like a ground loop to me. I would move your monitors, usb hub, etc. to the same outlet as all of your audio gear. Basically, anything connected to the system should be running through the same outlet, unless your outlets are wired with isolated grounds.

[viaspiaggia]

thanks to you both - I understand electricity just enough to do some basic stuff but not as thoroughly as I should.

John what would cause a ground loop to just perk up mid-afternoon and die back by late evening? The master electrician at Home Depot also recommended isolating the grounds as he suspected it was CFL / neon noise from somewhere in the house or nearby. We're in the city in a 110 year old house so anything is possible.

What should the lifespan be of a decent quality power supply like a Monster Power?

The new wrinkle is that after it went away in the basement I went upstairs to watch TV and heard the LCD TV in our den making the same noise! Like a gremlin in the wires following me.

All the outlets test out fine with my shiny new outlet tester, so I'm at least breathing easier, now to test all the outlets on those strips...

Thanks again!

[John_Toolbox]

Originally Posted by viaspiaggia

thanks to you both - I understand electricity just enough to do some basic stuff but not as thoroughly as I should.

John what would cause a ground loop to just perk up mid-afternoon and die back by late evening? The master electrician at Home Depot also recommended isolating the grounds as he suspected it was CFL / neon noise from somewhere in the house or nearby. We're in the city in a 110 year old house so anything is possible.

What should the lifespan be of a decent quality power supply like a Monster Power?

The new wrinkle is that after it went away in the basement I went upstairs to watch TV and heard the LCD TV in our den making the same noise! Like a gremlin in the wires following me.

All the outlets test out fine with my shiny new outlet tester, so I'm at least breathing easier, now to test all the outlets on those strips...

Thanks again!

The ground loop itself was always there in the wiring. The stray voltage that caused the noise is a result of a combination of things. But without getting overly technical, the voltage in your lines is never exactly 120volts, it fluctuates depending on the amount of power other people are using on the grid. Add to that, your gear draws a slightly different amount of power depending on what it's doing. So under the right conditions, the ground loop will manifest itself as noise. I have a flourescent light in my garage, which has a slight hum normally, but when I plug in my heat gun, and put it on the 50% setting, the flourescent light goes crazy and makes a really loud hum. The rest of the time it's fine.

[viaspiaggia]

thanks again guys, everything tests out fine, and after another week or so of this randomly occurring gremlin in my studio and the TV upstairs, it's mostly gone.

NOW however my right rear surround speaker has an intermittent good old fashioned ground hum sound. Turning the CFL bulb near it off and on sometimes changes it but not always, and this morning it's sort of just wavering and pulses louder and softer from time to time. This speaker is plugged in to the same Monster Power conditioner / switcher that all the audio gear is on. Is it safe to assume this is some component of the same underlying issue? The other noise was on the different circuit down here...

Gotta find time to get that electrician in!

[John_Toolbox]

CFLs or any fluorescents for that matter are not ideal for a studio, your speakers might be picking up some noise from the ballast in that CFL. Cheap dimmer switches with incandescent bulbs can even be a problem. I'm not really sure what to expect from LEDs, as they have a transformer in them.

But you said this is a 100+ year old house, that means it could be just about anything. Even with my 25-30 year old house I am amazed at how much havoc the previous owner was able to wreak on the electrical system.

[viaspiaggia]

Thanks John. I always say the disadvantage of having a studio in my basement is I have a basement in my studio - appliances, work lights, furnace, etc etc. Usually not a problem but just complicates things!

[John_Toolbox]

Originally Posted by viaspiaggia

Thanks John. I always say the disadvantage of having a studio in my basement is I have a basement in my studio - appliances, work lights, furnace, etc etc. Usually not a problem but just complicates things!

Well, mine started as a 3 season porch. Very hard to keep it cool in the summer, the roof is not vented and with all of my gear on it gets hot in here when the sun is out!