Affordable AC line noise filtering
Old 7th March 2006
  #1
Gear Head
 
amuro73's Avatar
 

Thread Starter
Affordable AC line noise filtering

I've been researching options for filtering noise that travel through my power circuit. I can hear the motor of my washing machine through my speakers! I know that plugging audio equipment into its own isolated circuit is ideal, but that's not an option now. So, I need a plug-in hardware to deal with the noice.

I know that part it is caused by ground loop. Upon someone's suggestion, I plugged in my power amp using a 3-prong to 2-prong converter, and the hum was reduced 80-90%, though not completely gone. The above waching machine motor noise was traveling through the ground line, apparently.

So, with all that said, I'm picked out some products -- if any of you have any experience with these devices, please let me know. Thanks!

Ebtech Hum X
This looks like just the ticket for isolating my power amp and removing the noise traveling through ground. A bit costly.

AudioPrism QuietLine
This looks intereting but since the plug is 2-prong, I'm guessing that it doesn't deal with noise traveling through the ground line. But this combined with above may eliminate all noise?


Triprite Isobar
This is a surge suppressor/noise filter. I know most cheap ones (even those that claim to have a filter) are ineffective, but these look like perhaps a higher grade one that may work.

Any other solutions? I'm hoping for <$100 total. At the very least, if I can isolate the power amp's ground line noise, I'll be happy. Thanks!

ari
Old 7th March 2006
  #2
Lives for gear
 
Albert's Avatar
 

Tripplite makes excellent products in my opinion, I have a bunch of their rack mount IsoBar 12 units, but I don't think that Tripplite will do much for your hum problem.

Of the other two, I'd probably go for the EbTech, although I personally haven't used it.

Another option is to maybe don't do the laundry when you are recording in your studio? tutt
Old 7th March 2006
  #3
Gear nut
 

Quote:
Originally Posted by amuro73
I plugged in my power amp using a 3-prong to 2-prong converter
This is VERY DANGEROUS! Seriously - doing that can lead to fires, death, etc. Go back to plugging in the 3-pong end correctly and find a different way to eliminate the noise.
Old 7th March 2006
  #4
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vince @ speck's Avatar
 

It's a simple solution that's often overlooked... use a line filter on the offending source of line noise. Try an AC line filter on the washing machine!
Old 7th March 2006
  #5
Gear Guru
 
Ethan Winer's Avatar
 

Lightbulb

Ari,

> I've been researching options for filtering noise that travel through my power circuit. I can hear the motor of my washing machine through my speakers! <

See the second half of this article:

www.ethanwiner.com/dimmers.html

It shows how to make a DIY RFI filter that's really cheap but very effective.

--Ethan
Old 7th March 2006
  #6
Gear Head
 
amuro73's Avatar
 

Thread Starter
Quote:
Originally Posted by mikedaul
This is VERY DANGEROUS! Seriously - doing that can lead to fires, death, etc. Go back to plugging in the 3-pong end correctly and find a different way to eliminate the noise.
Yes, I realize that! It was tried just for a very short period to isolate/identify the problem. I have no intention of using any piece of equipment without proper grounding.

ari
Old 7th March 2006
  #7
Gear Head
 
amuro73's Avatar
 

Thread Starter
Quote:
Originally Posted by Ethan Winer
Ari,

> I've been researching options for filtering noise that travel through my power circuit. I can hear the motor of my washing machine through my speakers! <

See the second half of this article:

www.ethanwiner.com/dimmers.html

It shows how to make a DIY RFI filter that's really cheap but very effective.

--Ethan
Yes, Ethan, you responded to another post of mine on the same topic a while ago. I'd really love to do what you're suggesting, but unfortunately I am stuck on figuring out exactly which part from Mouser or Digi-Key is the correct RFI filter for my needs.

ari
Old 7th March 2006
  #8
Gear Head
 
amuro73's Avatar
 

Thread Starter
Quote:
Originally Posted by vince @ speck
It's a simple solution that's often overlooked... use a line filter on the offending source of line noise. Try an AC line filter on the washing machine!
Well, what I'm actually hoping to do is to plug an AC line filter on the power amp, so that that elment is isolated. The noise can travel through the rest of my system (I know it's not great, but for the time-being) as long as my power amp remains noise-free.

I am just researching and trying to figure out which AC line filtering product is the most cost-effective way to go.

ari
Old 7th March 2006
  #9
Gear Head
 
amuro73's Avatar
 

Thread Starter
Quote:
Originally Posted by Ethan Winer
Ari,

> I've been researching options for filtering noise that travel through my power circuit. I can hear the motor of my washing machine through my speakers! <

See the second half of this article:

www.ethanwiner.com/dimmers.html

It shows how to make a DIY RFI filter that's really cheap but very effective.

--Ethan

Ethan and others,

Will one of these do it?

http://cgi.ebay.com/NEW-EMI-POWER-LI...QQcmdZViewItem

http://cgi.ebay.com/CORCOM-10VK6-RFI...QQcmdZViewItem

Thanks!

ari
Old 7th March 2006
  #10
Gear addict
 
KurtR's Avatar
 

Old 8th March 2006
  #11
Gear Guru
 
Ethan Winer's Avatar
 

Lightbulb

Ari,

> Will one of these do it? <

The photo of the first link doesn't show how many stages it has, but the second one does show that and this is definitely the right type.

--Ethan
Old 8th March 2006
  #12
Gear nut
 

Quote:
Originally Posted by amuro73
Yes, I realize that! It was tried just for a very short period to isolate/identify the problem. I have no intention of using any piece of equipment without proper grounding.

ari
Good to hear

I feared you were running this way permanently and just looking to remove that extra 10% of noise...
Old 9th March 2006
  #13
Gear Head
 
amuro73's Avatar
 

Thread Starter
Quote:
Originally Posted by Ethan Winer
Ari,

> Will one of these do it? <

The photo of the first link doesn't show how many stages it has, but the second one does show that and this is definitely the right type.

--Ethan

Thanks Ethan! That helps a lot. I'll try 'em.

ari
Old 10th March 2006
  #14
Gear maniac
 
Trancetones's Avatar
 

Buy a grounding pipe clamp in the electrical section of your home depot and a roll of green 12 guage wire and connect the clamp to a cold water pipe (I use the outdoor hose pipe.) Turn off your circuit breaker and remove the ground from the outlet for your audio gear and attach the wire from the ground screw on the outlet to the ground screw on the pipe clamp. Total cost about $25-
Old 10th March 2006
  #15
Gear nut
 
Sensater's Avatar
 

Quote:
Originally Posted by Trancetones
Buy a grounding pipe clamp in the electrical section of your home depot and a roll of green 12 guage wire and connect the clamp to a cold water pipe (I use the outdoor hose pipe.) Turn off your circuit breaker and remove the ground from the outlet for your audio gear and attach the wire from the ground screw on the outlet to the ground screw on the pipe clamp. Total cost about $25-
That's exactly what I did at my apt. It's an old building and most outlets are not grounded, but they are now! I bought the wire by the foot at Home Depot so it was pretty cheap. But does it have to be a cold water pipe? Also: I used a copper pipe that was exposed in the wall, which is water service for the upstairs apt. If I experience an electrical problem and electricity is shunted to the ground, does this present a danger for the upstairs water users? Or will the lesser resistance to earth mean that the juice will go that way for sure?
Sorry for the brief threadjack...
-Sen
Old 25th May 2011
  #16
Gear interested
 

Grounding to Pipes

Quote:
Originally Posted by Sensater View Post
That's exactly what I did at my apt. It's an old building and most outlets are not grounded, but they are now! I bought the wire by the foot at Home Depot so it was pretty cheap. But does it have to be a cold water pipe? Also: I used a copper pipe that was exposed in the wall, which is water service for the upstairs apt. If I experience an electrical problem and electricity is shunted to the ground, does this present a danger for the upstairs water users? Or will the lesser resistance to earth mean that the juice will go that way for sure?
Sorry for the brief threadjack...
-Sen
Guys, Do not ground anything to a metal supply pipe in your home or apartment. You will put any plumber (or your self) into a direct risk for electrocution. You never know if there is a "break" in the metal pipe supply line with a plastic one. The only safe (for everyone) means to properly ground out an electrical device or panel is to run a copper gound wire outside to a grounding rod post driven into the (what else) ground. I'm not sure of the depth but I think it's 8 feet. Please check your local electrical codes for the proper grounding methods.

Last edited by jaytmoon; 25th May 2011 at 03:45 PM.. Reason: addl info
Old 25th May 2011
  #17
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nosebleedaudio's Avatar
 

Quote:
Originally Posted by jaytmoon View Post
Guys, Do not ground anything to a metal supply pipe in your home or apartment. You will put any plumber (or your self) into a direct risk for electrocution. You never know if there is a "break" in the metal pipe supply line with a plastic one. The only safe (for everyone) means to properly ground out an electrical device or panel is to run a copper gound wire outside to a grounding rod post driven into the (what else) ground. I'm not sure of the depth but I think it's 8 feet. Please check your local electrical codes for the proper grounding methods.
Then it MUST be bonded/connected to the main AC neutral/ground..
By code ALL grounds MUST be bonded together; ground rods, water pipes..
Old 27th October 2013
  #18
Lives for gear
 

Quote:
Originally Posted by amuro73 View Post
I've been researching options for filtering noise that travel through my power circuit. I can hear the motor of my washing machine through my speakers! I know that plugging audio equipment into its own isolated circuit is ideal, but that's not an option now. So, I need a plug-in hardware to deal with the noice.

I know that part it is caused by ground loop. Upon someone's suggestion, I plugged in my power amp using a 3-prong to 2-prong converter, and the hum was reduced 80-90%, though not completely gone. The above waching machine motor noise was traveling through the ground line, apparently.

So, with all that said, I'm picked out some products -- if any of you have any experience with these devices, please let me know. Thanks!

Ebtech Hum X
This looks like just the ticket for isolating my power amp and removing the noise traveling through ground. A bit costly.

AudioPrism QuietLine
This looks intereting but since the plug is 2-prong, I'm guessing that it doesn't deal with noise traveling through the ground line. But this combined with above may eliminate all noise?


Triprite Isobar
This is a surge suppressor/noise filter. I know most cheap ones (even those that claim to have a filter) are ineffective, but these look like perhaps a higher grade one that may work.

Any other solutions? I'm hoping for <$100 total. At the very least, if I can isolate the power amp's ground line noise, I'll be happy. Thanks!

ari
Now, I have not tried these following product, but it also supplies current for anything on the same AC circuit, whether plugged in or not. It's basically has a large choke inside. I've been told by people I know in the audio industry that sell this stuff for large home theater installs and they swear by it. Yes, I know it's more than the $100 products you speak of, but it's VERY expensive, but the products are made by Richard Gray Power Company. Sometimes you can get product on eBay and other areas at a discount. Ask about their power station products. I heard they are VERY cool products, especially if you have big power amps, TVs, or basically lots of current. There is also MIT Cables, they make a patented filter they have AC receptacles and their priced around the $175 price range and it replaces your AC wall outlets, but they are also better gripping hospital grade, so they aren't supposed to arc and cause any sparks, when you plug and unplug power cables into the AC wall outlet. I think Furman/Panamax also makes a wall outlet that you might try.

I am also investigating this very subject as well, and what I find helpful is calling the companies and talking to them directly. Some won't try to oversell you products, some will. The problem is that some of the cheaper products, simply don't work well or solve all of the REAL problems that we encounter, so that's something to be aware of.

I bought a ac sniffer, but it only measures radio frequency noise between 300KHz-700KHz on 120VAC 60Hz wall outlets. But they can be had for $80 or less through eBay. The product is called the Entech Wideband power line noise analyzer. They are actually marketed by Monster Cable, but on the back, it actually say AlphaLab, Inc Salt Lake City, UT Model Sniffer V2.0.

I actually encountered radio stations coming through the same wall outlet that my clock radio was plugged in, but the radio was turned off. Go figure that one out. Also, when I turn the lights on and it's a light on the same circuit as the wall plug, the noise increases. Drag. I also have a lot of noise on my TV as well. I'm personally going to be checking out the RGPC products, but I'm gathering information first and then I have to call them to verify which products will actually help my situation. All I know is sometimes, it's best to spend the money and avoid more headaches as sometimes, the cheaper products may not be doing everything you need to have done. I guess it goes with the territory..

But these people will ask you for a laundry list of what equipment you have connected, why amp circuits, what symptoms you've had and they hopefully will be better equipped to suggest the right equipment. Power has lots of aspects that have to be considered for optimal performance and protection of what we have and unfortunately, what comes out of the wall isn't always that great.

Question, do you have dedicated circuits so your outlets aren't sharing or close to a refrigerator, microwave, etc. or some other product that emits lots of noise? Sometimes a dedicated line might be what you need as well.

Good luck to you, I hope your issue gets resolved.
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