• Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
    Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.

Internally Grounded PSU?

Megalith

Megalith

24-bit/48kHz
Joined
Aug 20, 2006
Messages
13,000
Okay, so I finally bought a cheater plug and tried it with my PC---the whining/buzzing that was being transmitted into my audio stream is completely gone. While I would love to try to figure out how to break the ground loop, I thought it'd be easier to find a PSU that is grounded internally and features only a two-prong plug.

Do these even exist?
 
You do realize that the ground pin on the power cord actually goes to the outside of your house via a copper wire and is connected to an aluminum pole that's deep into the ground. And the ground is completely independent of the power feed from the wall so you dont actually have to ground anything. And the main reason for the grounding wire is to trip the circuit breakers.
 
sok0 said:
You do realize that the ground pin on the power cord actually goes to the outside of your house via a copper wire and is connected to an aluminum pole that's deep into the ground. And the ground is completely independent of the power feed from the wall so you dont actually have to ground anything. And the main reason for the grounding wire is to trip the circuit breakers.
Click to expand...

you sir need to read this book.
http://en.wikipedia.org/wiki/National_Electrical_Code

Megalith said:
Okay, so I finally bought a cheater plug and tried it with my PC---the whining/buzzing that was being transmitted into my audio stream is completely gone. While I would love to try to figure out how to break the ground loop, I thought it'd be easier to find a PSU that is grounded internally and features only a two-prong plug.

Do these even exist?
Click to expand...


You do need to have a grounded plug for your computer because it grounds the case.

 
Last edited:
Megalith said:
Okay, so I finally bought a cheater plug and tried it with my PC---the whining/buzzing that was being transmitted into my audio stream is completely gone. While I would love to try to figure out how to break the ground loop, I thought it'd be easier to find a PSU that is grounded internally and features only a two-prong plug.

Do these even exist?
Click to expand...
What you proved to yourself is that you found the ground loop and that the noise is due to the ground loop. By cheater plug, I assume that you mean a 110VAC 3 prong to 2 prong adapter? That you can get from Walmart/Homedepot/Lowes/....

The PSU is wired internally to the 3rd prong & since it is mechanically/electrically attached to the case & m/b, it is the same ground in your sound system. This is different than the "cold" side of the 110VAC line & is why 2 pronged plugs are polarized .... one prong is wider than the other as one of those prongs is cold side. Neither of these prongs are connected to the PSU case.

Anyway ... without knowing anything more about your audio system. It seems that you fixed the problem. Although if the audio system has its own amp & power and its own 3 prong 110VAC connector, I would be more inclined to put the adapter there.

Are you using a power strip surge protector? If not, it would be a good idea and may even fix the problem.
 
How about trying the cheater plug with each other device connected to your system, until the whining-buzzing goes away? If I could ground only one device in the system, it would be the computer's PSU because every other device goes to it and can ground the other devices.

Could the problem be ground loops inside the PC case? What happens if you try to insulate the mobo from the case with washers, leaving only the power connectors and rear card brackets as ground points?

Epanorama's ground loop FAQ
 
I haven't tried the cheater plug with any other device, but the whining/buzzing definitely goes away when I use it with my PSU. I am pretty sure it might indeed be a ground loop issue within the PC itself, since the sound can be heard coming from within it (which is then transmitted/duplicated through my speakers). I think a couple of days back I unhooked practically everything from my home theater system (TV, receiver, speakers, amps) with the PC on, and it was still making the noise.

Last night I noticed that it would even transmit a strange noise through my speakers matching my keystrokes in the bios (the sound would last only as long as I held an arrow key down).

I'm pretty much out of options, but last night I ordered some ferrite cores for my AC and HDMI cable going into the PC, as well as an Ebtech Hum X.
 
The most specific solution for your problem is a ground loop isolation transformer, but it could be very expensive ($100-$1000). They exist for audiophile and industrial purposes afaik. For example, I think richard gray power company (??) includes that with their power conditioners, or you could get a good old topaz on ebay.

Or maybe put each component on a separate surge protector (w/ good emi+rfi filtering), or maybe run an extension cord so they're on different circuits altogether. I assume they'd filter on the ground as well.

But don't just take out the ground, or connected electronics will have a very, very short lifespan. Also uh.... you can complain to the PSU mfr, it shouldn't be doing what you're describing.
 
I can't blame the PSU companies, since I've tried both a Corsair HX620 and a Seasonic X750, and both exhibit the same problem. It just seems to be the combination of hardware.

Speaking of isolation transformers, I was thinking of trying the Tripp-Lite ones, but the 1000W one costs quite a bit. I'll have to try that if the ferrites and Ebtech don't work, though.
 
You know, I had this problem at my parent's house when I tried to play movies via my laptop on their home theater setup (solution: run off the battery).

But-- I don't have this issue here for some reason. I use cheap power conditioners ($20 "opti-ups" avr transformer), maybe that's what you need. APC makes a 1200watt (LE1200) for like $60, and unlike mine it includes an emi/rfi filter on the outputs. The tripp-lite equivalent is like $120, if that's the one you were looking at, and I think the difference is more voltage taps for correction, but all you really want is the transformer for this purpose.

My folks also have far more electronics failures than should be, but nobody's ever found the cause. The only other place I've seen what you described was my first apt, which eventually had an electrical fire on that line due to improper wiring (!).
 
venm11 said:
The most specific solution for your problem is a ground loop isolation transformer, but it could be very expensive ($100-$1000). They exist for audiophile and industrial purposes afaik. For example, I think richard gray power company (??) includes that with their power conditioners, or you could get a good old topaz on ebay.

Or maybe put each component on a separate surge protector (w/ good emi+rfi filtering), or maybe run an extension cord so they're on different circuits altogether. I assume they'd filter on the ground as well.

But don't just take out the ground, or connected electronics will have a very, very short lifespan. Also uh.... you can complain to the PSU mfr, it shouldn't be doing what you're describing.
Click to expand...

I ran a house full of electronics all hooked up with cheater plugs and no grounds for over a decade and never had something fail. a lot of houses in my area don't even have grounded outlets (except gfci outlets by the sinks). there is no outbreak of failing electronics because of this.
Posted via [H] Mobile Device
 
ocellaris said:
I ran a house full of electronics all hooked up with cheater plugs and no grounds for over a decade and never had something fail. a lot of houses in my area don't even have grounded outlets (except gfci outlets by the sinks). there is no outbreak of failing electronics because of this.
Posted via [H] Mobile Device
Click to expand...

The ground is more about protecting the user of the device from getting electrocuted.
 
drescherjm said:
The ground is more about protecting the user of the device from getting electrocuted.
Click to expand...

My response was too

"But don't just take out the ground, or connected electronics will have a very, very short lifespan."

Plenty of electronics with grounded plugs live a very long lifespan without using the ground. Its FUD to say that not using the ground will cause everything to have a "very, very short lifespan".
 
Last edited:
I'm not an electrician, so correct me if i'm wrong. My 3 theories:
a) your ground system is working like a giant antenna
b) your ground system is improperly wired and somehow making contact to voltage sources (my house actually had live wire touching some of the plumbing... fun, and doesn't ground sometimes connect to plumbing?)
c) there's an electronic device on your ground system that is for some reason sending voltage down the ground.
 
Megalith said:
I can't blame the PSU companies, since I've tried both a Corsair HX620 and a Seasonic X750, and both exhibit the same problem. It just seems to be the combination of hardware.

Speaking of isolation transformers, I was thinking of trying the Tripp-Lite ones, but the 1000W one costs quite a bit. I'll have to try that if the ferrites and Ebtech don't work, though.
Click to expand...

IF you have standard cable (not fiber or FIOS) coming into your house, unhook it from anything, even your modem.

Now see if you still have the noise. Make sure nothing from your sound system is connected to your computer, just your monitor, keyboard and mouse. If you are going to use your cheater plug use it on your subwoofer if you have a powered one. Add each item back in until you find the cause of the noise.

TV cable has been an issue for years, I used to be able to read a 60 volt potential between my cable ground and my computer case. (you measure this with the cable unhooked). If your cable is the issue call your cable company and have them fix it, the condition means a bad cable ground and puts the cable company in violation of law.

Make sure your AC outlet is not only wired properly, make sure you have a good ground to your mains. A cheap tester from Sears can tell you this.

Computers PSUs use a three prong plug for a reason, YOUR SAFTEY. If you can read voltage from your computer case and the center screw (clean the paint off the screw) you have a serious problem. The last thing you want is to become the connection from your computer case and a good ground, might not kill you but could be a bit more than a shocking experience.

Find the real problem, work arounds are never a good idea in these cases.
 
Unplugging the cable modem was the first thing I tried. That isn't the problem. I also verified that the outlet is grounded properly.
 
Megalith said:
Unplugging the cable modem was the first thing I tried. That isn't the problem. I also verified that the outlet is grounded properly.
Click to expand...

Cool, I understand unplugging the cable modem, however, any and everything else that might be attached to that cable would be in the same circuit. (TV, Cable box etc) so they would all have to be unhooked at the same time. Keep in mind, even something as simple as a coax (RCA Cable) based digital connection will share the same ground as everything else in the circuit, so it all has to be disconnected at the same time.

It's a bitchy issue to track down for sure but take it one step at a time starting with a totally bare computer. If you plug in headphones to speaker out, with nothing else attached to the machine, the problem is in the machine. If that happens you might try your cheater plug on your monitor, if your monitor is a three wire unit.

Floating grounds can be the worst, been there, done it, even have a t-shirt somewhere.

Luck man.

Let me add, don't forget while unplugging everything, unplug the cat-5 or usb from the modem to the computer as well.
 
Psi* said:
What you proved to yourself is that you found the ground loop and that the noise is due to the ground loop. By cheater plug, I assume that you mean a 110VAC 3 prong to 2 prong adapter? That you can get from Walmart/Homedepot/Lowes/....

The PSU is wired internally to the 3rd prong & since it is mechanically/electrically attached to the case & m/b, it is the same ground in your sound system. This is different than the "cold" side of the 110VAC line & is why 2 pronged plugs are polarized .... one prong is wider than the other as one of those prongs is cold side. Neither of these prongs are connected to the PSU case.

Anyway ... without knowing anything more about your audio system. It seems that you fixed the problem. Although if the audio system has its own amp & power and its own 3 prong 110VAC connector, I would be more inclined to put the adapter there.

Are you using a power strip surge protector? If not, it would be a good idea and may even fix the problem.
Click to expand...

The only reason two prong plugs are "polarized" is because of the inherent danger that light fixtures present to people, nothing else. There is no difference between hot and neutral in a live complete circuit. Grabbing one or the other will fry your ass.


BillR said:
Cool, I understand unplugging the cable modem, however, any and everything else that might be attached to that cable would be in the same circuit. (TV, Cable box etc) so they would all have to be unhooked at the same time. Keep in mind, even something as simple as a coax (RCA Cable) based digital connection will share the same ground as everything else in the circuit, so it all has to be disconnected at the same time.

It's a bitchy issue to track down for sure but take it one step at a time starting with a totally bare computer. If you plug in headphones to speaker out, with nothing else attached to the machine, the problem is in the machine. If that happens you might try your cheater plug on your monitor, if your monitor is a three wire unit.

Floating grounds can be the worst, been there, done it, even have a t-shirt somewhere.

Luck man.

Let me add, don't forget while unplugging everything, unplug the cat-5 or usb from the modem to the computer as well.
Click to expand...

One thing to remember is that every cicruit in the hosue will share the same ground and neutral since they're connected together via bus bars in the breaker box. So something on a completely difference circuit could possibly be injecting noise into the grounding system.
 
Last edited:
ryan_975 said:
The only reason two prong plugs are "polarized" is because of the inherent danger that light fixtures present to people, nothing else. There is no difference between hot and neutral in a live complete circuit. Grabbing one or the other will fry your ass.




One thing to remember is that every cicruit in the hosue will share the same ground and neutral since they're connected together via bus bars in the breaker box. So something on a completely difference circuit could possibly be injecting noise into the grounding system.
Click to expand...

Yes, but, when he uses the cheater he isolates that particular ground. You start the search locally, trace back from there if needed.
 
Yeah, I should have been more clear---when I said I unplugged my cable modem, I meant that I disconnected the coax from it. It goes directly into my cable modem and nothing else. Just for kicks, I started unplugging random things throughout the house one of those days, but still noise.
 
Megalith said:
Yeah, I should have been more clear---when I said I unplugged my cable modem, I meant that I disconnected the coax from it. It goes directly into my cable modem and nothing else. Just for kicks, I started unplugging random things throughout the house one of those days, but still noise.
Click to expand...

This noise, is it a low pitched hum?
 
The noises are mostly mechanical, typically a buzz or high-pitched whine.
 
Megalith said:
I haven't tried the cheater plug with any other device, but the whining/buzzing definitely goes away when I use it with my PSU. I am pretty sure it might indeed be a ground loop issue within the PC itself, since the sound can be heard coming from within it (which is then transmitted/duplicated through my speakers). I think a couple of days back I unhooked practically everything from my home theater system (TV, receiver, speakers, amps) with the PC on, and it was still making the noise.

Last night I noticed that it would even transmit a strange noise through my speakers matching my keystrokes in the bios (the sound would last only as long as I held an arrow key down).

I'm pretty much out of options, but last night I ordered some ferrite cores for my AC and HDMI cable going into the PC, as well as an Ebtech Hum X.
Click to expand...
You've got me confused: so you were hearing a noise through your *unplugged* speakers when you did this? And the amp for your speakers was not turned on or plugged in to the AC? Also: is there another receptacle that you can plug your computer's PSU into? Try switching what receptacle you have the amp plugged into, maybe?

The ferrite chokes should help the issue, too. If you don't have them yet, you can try coiling your power cords and/or speaker wires to minimize the noise.
BillR said:
Luck man.
Click to expand...
Let us know how you fix this!

edit: does the noise change in any way while the computer is under load?
 
Sorry, I was just saying in general that the sound coming through my audio stream was mirroring the noise that was stemming from the components inside my PC. I never tried unplugging my speakers; there's no point for me to do that as far as I can tell. The strange thing, though, was that I tried changing my receiver to another HDMI input, but I was still getting the sounds through my speaker---so there was definitely something ground related going on, and later verified by the cheater plug I used.

My Ebtech Hum X seems to have gotten here a day early---and it worked! I only tried booting up Mass Effect, but the buzzing is completely gone.

(The noise did indeed occur only when my computer was under load---more specifically, my graphics card, as the noises only occurred within a game or scrolling through a webpage [and possibly even during video playback]. I would imagine that the supposed, natural buzzing/whining that occurs from within video cards was somehow being thrown into my audio stream because of a ground loop going on between the Radeon 5850 and other components, such as the PSU.)
 
Last edited:
Awesome, glad to hear that you've got yourself a solution. I had a fanless, SSD-driven computer that I used for a while that had video running through an 8800GT and that card was noisy! I could hear it tick and buzz whenever I was scrolling a document or playing a game or video. I never had any electrical problems with it, but I guess some coil or choke in there was making an awful lot of noise.
 
You must log in or register to reply here.
Back
Top