So on the topic of noise on the mains, some will come from the incoming mains (outside) and some will be generated from what is in your house (inside)
I have no measurement equipment so I can't confirm in my case, but I would be interested to know in general if proximity to the source is a significant factor and so the majority of noise comes from (inside) or is it mostly from (outside) the property travelling in from everybody else on the line?
Any ideas?
Thanks,
I have no measurement equipment so I can't confirm in my case, but I would be interested to know in general if proximity to the source is a significant factor and so the majority of noise comes from (inside) or is it mostly from (outside) the property travelling in from everybody else on the line?
Any ideas?
Thanks,
Try using a pocket radio on the MW / AM band around the house to find noise.
American ground and neutral is same, less chances of line noise from the neighbors.
Tighten all the screws in the breaker and switch boards, and use a infra red thermometer to check for hot joints, arcing wires are hot.
Use insulated screw drivers and other tools, preferably after turning off the mains.
Arcing is a source of line noise.
I am not responsible for any injuries you may get, and will tell you to follow your local regulations and laws, and use common sense and all precautions.
If I am working on electricity, I pull the incoming fuses, then work.
If really not possible, I have somebody with a big wooden stick near me, told to hit me and get me away from the live wire if there is an issue...
Wood is an insulator, the person with stick will not get electrocuted.
And believe me, 60V can cause your heart to stop.
Keep the other hand away from any surface while working, it can cause a ground path trough your heart.
If you feel this is above your skill level, call in a professional, it is cheaper than your life.
American ground and neutral is same, less chances of line noise from the neighbors.
Tighten all the screws in the breaker and switch boards, and use a infra red thermometer to check for hot joints, arcing wires are hot.
Use insulated screw drivers and other tools, preferably after turning off the mains.
Arcing is a source of line noise.
I am not responsible for any injuries you may get, and will tell you to follow your local regulations and laws, and use common sense and all precautions.
If I am working on electricity, I pull the incoming fuses, then work.
If really not possible, I have somebody with a big wooden stick near me, told to hit me and get me away from the live wire if there is an issue...
Wood is an insulator, the person with stick will not get electrocuted.
And believe me, 60V can cause your heart to stop.
Keep the other hand away from any surface while working, it can cause a ground path trough your heart.
If you feel this is above your skill level, call in a professional, it is cheaper than your life.
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There are site and country-specific issues that might go against this, but in the US I don't recall ever having a noise problem coming from outside on the mains (except for serious supply interruptions or lightning-related issues). In my experience, it's much more common for something in your house to be causing noise. Ground loops are quite common. Noisy power supplies, spark igniters, and transmitters of all kinds (cellular phones, WiFi sources, etc.) are also typical noise producers.
Any number of things can go wrong at a specific location, but if you're in a relatively modern home with decent electrical service without faults, I think the above description is valid.
Any number of things can go wrong at a specific location, but if you're in a relatively modern home with decent electrical service without faults, I think the above description is valid.
I live in Argentina, a eternally chaotic place. During several years I had a strange noise as spreading harmonics of the 50Hz from mains but in such an intensity that the line filters capacitor(s) inside PC power supply and my own designed SMPS, made audible relatively loudy: no need to be in complete silence to listen acoustic noise emanating from them. Once, I catch a large 47uF capacitor 440VAC from air conditioning compressor, put a pair of cables and a plug and inserted it in the first outlet after the thermomagnetic switches at home. All those small caps went completely silent but the large new produced some sound too and a small temperature increase above ambient. So I thought it was the solution.
During a T storm one of the 13.2KV isolator in the medium voltage grid went blown (catched fire) as a result of partial impinguing of a thunder on the line. I have the video captured with my phone.
When the company came to replace the isolator, the capacitor stop sounding. I removed it and saved for eventual future use. The isolator wasn't porcelain as usual: it was made of PVC, or similar plastic. So it was clearly the culprit with a large leackage from the conductors.
Some time after, a second isolator spontaneously inflamed the same way.
During a T storm one of the 13.2KV isolator in the medium voltage grid went blown (catched fire) as a result of partial impinguing of a thunder on the line. I have the video captured with my phone.
When the company came to replace the isolator, the capacitor stop sounding. I removed it and saved for eventual future use. The isolator wasn't porcelain as usual: it was made of PVC, or similar plastic. So it was clearly the culprit with a large leackage from the conductors.
Some time after, a second isolator spontaneously inflamed the same way.
Some things in the house are terrible for mains interference.
I have had trouble with fridges in the past.
Even something as small as a 30 watt soldering iron can put noise on the mains on power up/down.
I built an amplifier using irfp240/9240.
Got it up and running and sounded great.
So turned off soldering iron had finished with it.
Blew amp up.
The glitch down the mains had got into amp and popped the mosfets.
Motors can be very noisy.
I have designed a few circuits to drive motors and great care has to be taken to decouple properly.
A 100uf and 100nf across the motor power supply helps a lot.
I have had trouble with fridges in the past.
Even something as small as a 30 watt soldering iron can put noise on the mains on power up/down.
I built an amplifier using irfp240/9240.
Got it up and running and sounded great.
So turned off soldering iron had finished with it.
Blew amp up.
The glitch down the mains had got into amp and popped the mosfets.
Motors can be very noisy.
I have designed a few circuits to drive motors and great care has to be taken to decouple properly.
A 100uf and 100nf across the motor power supply helps a lot.
One of my hobbies is amateur radio (HAM radio). Listening to news of the world, low-T old pharts complaining about their prostates and other medical issues, talking to random people howsoever briefly in Japan, Antarctica, South America, Africa, Australia, Russia and points in between has been fun.
The noise isn’t fun at all. I gave up trying to track down some sources of fun. Fluorescent lights, LED lights, refrigerator, WiFi, electric fence charger, many sources I ”sniffed out” with a smaller receiver. Neighbor’s appliances, and more.
I know that noise is out there, despite FCC regulations - a friend of mine fought for about three years to have a wire fixed on a power pole outside his house that was spilling all kinds of EM but the power company finally did send someone up there to sort it out.
I’d like to avoid as much indoor noise on my audio gear as possible, and am thinking about running shielded wiring from breaker box to a single wall outlet with two extension sockets about 12 feet away.
Question is, will this help, is it necessary (rather than using just 15A 12 AWG paired wire from point A to point B), and, what wire to use?
I’ve already spent over an hour online looking for shielded ELECTRICAL POWER wire, 600V (shielded, 10 AWG - it’s about a 70 foot run of wire) and so far am coming up with nearly nothing useful.
I can’t even find posts/threads discussing this although I have in the past read posts on audiogon and elsewhere mentioning it, I can’t find where someone has actually done it.
Can anyone help direct me one way or the other?
Thanks.
Norm
The noise isn’t fun at all. I gave up trying to track down some sources of fun. Fluorescent lights, LED lights, refrigerator, WiFi, electric fence charger, many sources I ”sniffed out” with a smaller receiver. Neighbor’s appliances, and more.
I know that noise is out there, despite FCC regulations - a friend of mine fought for about three years to have a wire fixed on a power pole outside his house that was spilling all kinds of EM but the power company finally did send someone up there to sort it out.
I’d like to avoid as much indoor noise on my audio gear as possible, and am thinking about running shielded wiring from breaker box to a single wall outlet with two extension sockets about 12 feet away.
Question is, will this help, is it necessary (rather than using just 15A 12 AWG paired wire from point A to point B), and, what wire to use?
I’ve already spent over an hour online looking for shielded ELECTRICAL POWER wire, 600V (shielded, 10 AWG - it’s about a 70 foot run of wire) and so far am coming up with nearly nothing useful.
I can’t even find posts/threads discussing this although I have in the past read posts on audiogon and elsewhere mentioning it, I can’t find where someone has actually done it.
Can anyone help direct me one way or the other?
Thanks.
Norm
At this point I’m thinking simple 10/2 - with ground - aluminum armored (BX) is going to be the best alternative, about $200 for a roll of 125 feet. Use steel boxes at outlets. Thanks.
Fridge, washer, drying machine, hand drills, and ANY SMPS, including your computer's.
Isolate using a dedicated line on a separate section of the mains fuse box - an Electrician is necessary here.
Otherwise use mains filters AC-side (but also in combination with the dedicated line).
Isolate using a dedicated line on a separate section of the mains fuse box - an Electrician is necessary here.
Otherwise use mains filters AC-side (but also in combination with the dedicated line).
Project’s at a standstill right now as we’ve fired the contractor for failure to complete project as contracted. Also had to get a structural engineer in to counter his claims that everything was done per code and per plans. Lawyered up and interviewing local contractors.
Meanwhile I’ve got a great electrician, but will be doing this part of the electric myself with his blessings. He saw how I wired our barndominium (15x30 apartment) and is cool with signing off on my work.
Thanks.
Meanwhile I’ve got a great electrician, but will be doing this part of the electric myself with his blessings. He saw how I wired our barndominium (15x30 apartment) and is cool with signing off on my work.
Thanks.
Have you thought of using spiral steel conduit as a shielding and protection medium for mains cabling?
I have a TV and OPPO205 connected to a separate wall mains outlet (had to lay an extension cord for this), to prevent SMPSs from spitting rubbish back into the mains feed, affecting sensitive audio gear.
My May DAC, Aleph J, NUC11 with its liner power supply share the same power outlet. If I plug the TV and/or OPPO 205 into the same wall outlet as my audio gear, I can clearly hear the difference.
Even worse, I tried powering up the NUC11 with a Meanwell SMPS... that was absolutely terrible. Then, I just plugged the SMPS into the mains... without using its DC rails at all...i.e. I did not have anything powered up by that SMPS... that was also terrible.
So.... it seems that switching noises do find their way back into sensitive gear.
I found that it's best to dedicate a wall outlet to be used only for audio gear, powered up with liner power supplies.
All other equipment powered with SMPSs should NOT be plugged into the same outlet. Dito for AC motors/compressors/neon lamps with dimmers.
Also, see here for all details re the above:
https://www.diyaudio.com/community/threads/post-you-smps-noise-spectrum-measurements.394518/
My May DAC, Aleph J, NUC11 with its liner power supply share the same power outlet. If I plug the TV and/or OPPO 205 into the same wall outlet as my audio gear, I can clearly hear the difference.
Even worse, I tried powering up the NUC11 with a Meanwell SMPS... that was absolutely terrible. Then, I just plugged the SMPS into the mains... without using its DC rails at all...i.e. I did not have anything powered up by that SMPS... that was also terrible.
So.... it seems that switching noises do find their way back into sensitive gear.
I found that it's best to dedicate a wall outlet to be used only for audio gear, powered up with liner power supplies.
All other equipment powered with SMPSs should NOT be plugged into the same outlet. Dito for AC motors/compressors/neon lamps with dimmers.
Also, see here for all details re the above:
https://www.diyaudio.com/community/threads/post-you-smps-noise-spectrum-measurements.394518/
If you can, use metal conduit, and two earthing points in the ground.
Or armored cable, connect the shield, or the metal conduit mentioned above, to Earth, have it checked, 200W lamp should glow brightly.
I had noise on my amp, crackling, and I found that Earth was open, using lamp, phase to Earth.
Went downstairs, the joint to the iron wire from my flat needed rework, many years since I did it, and lamp (40W filament ulb), started glowing dimly after that.
So I made some salt solution, and poured it down the earthing pipe, after some time the lamp glowed bright.
No crackling now
The amp is connected to my computer, and has a linear supply,, the computer had indeed been behaving erratically in other ways.
Here earthing method was a plate of iron, buried deep, with charcoal and salt, out with galvanized wire, and a pipe to top up moisture or salt.
Chemical earthing uses a copper coated pipe, and a deep hole filled with a special chemical.
Please see if that needs to be done. It should make a difference, and is a safety measure, though the US system has earth and ground connected at the poles, I believe.
Or armored cable, connect the shield, or the metal conduit mentioned above, to Earth, have it checked, 200W lamp should glow brightly.
I had noise on my amp, crackling, and I found that Earth was open, using lamp, phase to Earth.
Went downstairs, the joint to the iron wire from my flat needed rework, many years since I did it, and lamp (40W filament ulb), started glowing dimly after that.
So I made some salt solution, and poured it down the earthing pipe, after some time the lamp glowed bright.
No crackling now
The amp is connected to my computer, and has a linear supply,, the computer had indeed been behaving erratically in other ways.
Here earthing method was a plate of iron, buried deep, with charcoal and salt, out with galvanized wire, and a pipe to top up moisture or salt.
Chemical earthing uses a copper coated pipe, and a deep hole filled with a special chemical.
Please see if that needs to be done. It should make a difference, and is a safety measure, though the US system has earth and ground connected at the poles, I believe.
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