Reaching out once again .. HELP with noise.`

Copyright

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After multiple builds.. multiple sound cards.. onboard audio and external devices.. Only two things fixed my noise.. To start .. the noise is light during normal desktop use.. when games kick on the noise goes nuts and its a loud hum/buzz from my JBL Book shelves. Both units do it. I never had issues with my Kliplsch but it was a very different setup. Only thing that fixes it is a Ground loop isolator installing between the PC and speakers inline RCA. This however is having some effect on audio quality. There is some sort of ground loop issues going on. The only other thing I have thought of that might help is removing the ground pin on the book shelves. I''m lost. Even USB DAC's that are external had the same noise. The only unit that did not was the TEAC USB DAC I had for a little while. Does anyone have any ideas? I am using the onboard audio now on my Gigabyte Gaming 7 X470 and the noise is there. Even owned 3 different video cards and 3 different motherboards. Frustrated.. and stuck..
 

B00nie

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Are your outlets properly grounded?
PA equipment have a 'ground lifter' which isolates the audio signal from the ground. This will fix a ground loop. Perhaps you (the OP) could find a low cost signal relay box.
 

Copyright

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PA equipment have a 'ground lifter' which isolates the audio signal from the ground. This will fix a ground loop. Perhaps you (the OP) could find a low cost signal relay box.

Have a link?
 

Copyright

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Are your outlets properly grounded?

Well what helps me is that I was an electrician for 10 years. I swapped out the outlet to an audiograde outlet which is baiscally like a hospital plug that grabs much harder. When I turn off my fan in my office my speakers pop REALLY loud. From what I can SEE all grounds are connected and I am pretty sure I tested my DMM with hot to ground but I will go back and verify this. I will say the fan in m office is really strange. It's very picky on bulbs or it will pop a breaker.. same breaker that is on this circuit for my PC.. I have debated unhooking the fan just to test. Or maybe the fan it's self isn't properly grounded.
 

B00nie

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Well what helps me is that I was an electrician for 10 years. I swapped out the outlet to an audiograde outlet which is baiscally like a hospital plug that grabs much harder. When I turn off my fan in my office my speakers pop REALLY loud. From what I can SEE all grounds are connected and I am pretty sure I tested my DMM with hot to ground but I will go back and verify this. I will say the fan in m office is really strange. It's very picky on bulbs or it will pop a breaker.. same breaker that is on this circuit for my PC.. I have debated unhooking the fan just to test. Or maybe the fan it's self isn't properly grounded.

If you have pops when starting devices it may indicate a bigger problem. Or the fan motor lacks a suppressor cap. Most computer power supplies leak half the main voltage (with high resistance though) to the computer chassis and this can cause all sorts of havoc also with your audio gear.

You should get a professional electrician to perform phase difference and ground level difference measurements to your house. Older houses may lack a grounding cable and rely on 0 line coming from the power grid. I know I had to retrofit my house with one along with complete rewiring of the house.
 

Copyright

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If you have pops when starting devices it may indicate a bigger problem. Or the fan motor lacks a suppressor cap. Most computer power supplies leak half the main voltage (with high resistance though) to the computer chassis and this can cause all sorts of havoc also with your audio gear.

You should get a professional electrician to perform phase difference and ground level difference measurements to your house. Older houses may lack a grounding cable and rely on 0 line coming from the power grid. I know I had to retrofit my house with one along with complete rewiring of the house.

My Dad owns an electrical company.. I worked for his company for 10 years and not once did I ever heard of a phase difference and ground level difference measurement to the house. If you can explain what we are looking for and how to check for it I can gladly test it. I can wire a house from start to finish 100% complete. If this house wasn't a 2 story I would have dropped my own 20amp 12/2 line straight to my PC. Being a 2 story and a room that is on the other side of the house from the breaker box makes it nearly impossible without sheetrock repair etc. I am willing to try whatever you think will help.
 

Brian_B

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Well what helps me is that I was an electrician for 10 years. I swapped out the outlet to an audiograde outlet which is baiscally like a hospital plug that grabs much harder. When I turn off my fan in my office my speakers pop REALLY loud. From what I can SEE all grounds are connected and I am pretty sure I tested my DMM with hot to ground but I will go back and verify this. I will say the fan in m office is really strange. It's very picky on bulbs or it will pop a breaker.. same breaker that is on this circuit for my PC.. I have debated unhooking the fan just to test. Or maybe the fan it's self isn't properly grounded.


Yeah sounds like a wire is switched somewhere (hot/neutral or ground/neutral), or the outlet is "grounded" but it's a high resistance ground so the noise isn't able to get to ground easily.

A couple of easy things to check:

Turn off the fan/light entirely, and everything else you can on that same circuit - see if that fixes the problem.

Run a drop cord from an outlet on a different circuit to your PC setup - see if it occurs on that circuit as well.

If it's high resistance ground, a grounding rod (or two) in a couple of key areas could help clear that right up. There could be corrosion or a loose connection somewhere in the grounding network (maybe just that particular circuit, maybe the entire house).
 

Copyright

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Yeah sounds like a wire is switched somewhere (hot/neutral or ground/neutral), or the outlet is "grounded" but it's a high resistance ground so the noise isn't able to get to ground easily.

A couple of easy things to check:

Turn off the fan/light entirely, and everything else you can on that same circuit - see if that fixes the problem.

Run a drop cord from an outlet on a different circuit to your PC setup - see if it occurs on that circuit as well.

If it's high resistance ground, a grounding rod (or two) in a couple of key areas could help clear that right up. There could be corrosion or a loose connection somewhere in the grounding network (maybe just that particular circuit, maybe the entire house).

I'm surprised going through the UPS it doesn't clean it up... The PC is on the UPS but the speakers are on just the wall outlet... I can try some extension cords from the dining room which is usually on a 20amp breaker. Worth a shot!
 

Brian_B

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UPS rides (more or less) passively until it detects an outage, then it switches over. That's how they retain high efficiency. So if there's a wiring issue, unless your UPS is active and generating power, it will also pass through any wiring or grounding issues.
 

B00nie

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My Dad owns an electrical company.. I worked for his company for 10 years and not once did I ever heard of a phase difference and ground level difference measurement to the house. If you can explain what we are looking for and how to check for it I can gladly test it.

These tests are mandatory where I live. Basically you test for 100% isolation and 120° phase difference between the three phases that feed your house and you measure ground resistance (both 0 wire and safety ground) from each socket to your switch box. There should be zero leak phase by phase and low resistance (closed loop) from each socket to the switch box. Oh, and the switch box itself must naturally be grounded properly.
 

Copyright

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These tests are mandatory where I live. Basically you test for 100% isolation and 120° phase difference between the three phases that feed your house and you measure ground resistance (both 0 wire and safety ground) from each socket to your switch box. There should be zero leak phase by phase and low resistance (closed loop) from each socket to the switch box. Oh, and the switch box itself must naturally be grounded properly.

Man, I have been tryign to look this up online on how to test and cannot find anything. Where is it you live? I know I have been out of the game a good 15 plus years but I have not heard that being part of the code. Thanks for all the info!
 

Copyright

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UPS rides (more or less) passively until it detects an outage, then it switches over. That's how they retain high efficiency. So if there's a wiring issue, unless your UPS is active and generating power, it will also pass through any wiring or grounding issues.

Yeah, I kinda figured that was the case.. This is becoming super annoying :(
 

Brian_B

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Man, I have been tryign to look this up online on how to test and cannot find anything. Where is it you live? I know I have been out of the game a good 15 plus years but I have not heard that being part of the code. Thanks for all the info!

http://en-us.fluke.com/products/earth-ground/

Most jurisdictions don't require testing reports for residential/commercial and even some industrial so long as it's constructed with "best practices" for the area, so I'm not surprised you haven't seen anything despite having worked in electrical for a good deal.

Power plants and substations, however, pretty standard work.
 

B00nie

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Man, I have been tryign to look this up online on how to test and cannot find anything. Where is it you live? I know I have been out of the game a good 15 plus years but I have not heard that being part of the code. Thanks for all the info!
I live in Finland.

Here's the mandatory measurements:

Off-power measurements:
  • Measuring the insulation resistance.
  • Continuity check of the protective conductor
Continuity test is especially important when measuring the safety ground lead.
In practice its advisable to do the resistance measurement first because the protective conduit (PE) can be connected to 0 (N) or some of the phases and the measurement will detect the fault. If continuity measurement is done while PE is connected to a phase the measurement won't detect that.

After both off-power measurements have been done you can do powered measurements.

  • Mandatory theck of the fault circuit impedance to ensure the breaker works
The impedance is measured between (L) and safety ground (PE). The meter will report the minimum current required to activate the breaker either in 0.4 or 5.0 seconds depending on the type.
  • Short circuit impedance (not mandatory)
    • Cable protection breaker 'fuse' check between mains and PE
  • Mandatory check for phase rotation direction and continuity when doing a 3 phase installation
  • Check of the fault current safety breakers (mandatory test)
 

daglesj

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Try running it all off a big mains filter or UPS.

I run the mains for my rig through two lots of mains filters before it even hits the PC PSU. Ferrite cores on all the mains/power leads too. Even got extra ferrites on the power cables inside the PC.

Inky blackness (to quote a well used audiophile phrase)
 
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alxlwson

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OP, if you have an oscope, hook it up. Check quality of the sine wave. Check with fan on and fan off. Check it with various appliances/fixtures in the house on/off until you nail something down.
 

B00nie

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UPS rides (more or less) passively until it detects an outage, then it switches over. That's how they retain high efficiency. So if there's a wiring issue, unless your UPS is active and generating power, it will also pass through any wiring or grounding issues.

Yes the UPS that actually regenerate AC are expensive. But those are a holy grail of audio purists. Too bad many people get fooled into buying super expensive power cables instead :)
 

Megalith

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This has worked well for me.

humxsplashbanner.jpg
 

klm

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So have you figured this out yet? This is a problem I'm actually familiar to. In my case I usually hear some sort of intermittend static noise through the speakers when, for example, I move the mouse, watch a fullscreen video, or otherwise stress the computer. I have encountered it many times, and I have also managed to solve it. The problem is not RF or EM interference, nor is it dirty power. Power conditioners, ferrite cores and heavy shielding are not going to help. So far, it has ALWAYS been a grounding problem. The solution is quite easy: make sure your system is grounded at one point only (and try to use star grounding within your system). The noises you hear are small signals that should flow to earth via your ground connection, but somehow end up flowing through your audio gear because the path to earth is apparently routed through there. Sometimes, in a poorly grounded system, the noises or hum can become less when you touch the metal case on of your devices. This is an indication that your grounding needs work or that your system isn't grounded at all. For electrical safety and hum-free operation, a connection to earth somewhere is definitely needed. Especially switch mode power supplies tend to create a voltage on the case of your pc, which you feel as a slightly vibrating or tingling sensation when you touch the case, if your system has no connection to earth.

What happens when you connect multiple devices together, is that the shields around the cables are connected to the plugs on either side of the cable, and the cables connect the cases of multiple devices together. Thus a chain is formed from the speakers via your DAC back to your PC case, and all these devices now have their grounds connected. As long as one, and only one, of these devices has a connection to earth, you're good (and safe by the way). The problems start when you plug in multiple devices with a grounded plug, and also connect these devices to each other via audio and/or usb cables. Now there are many roads the signals can take, and then the noise problem starts.

In your first post you mention disconnecting the grounding pins on your (active) speakers. It is a good idea to try this. You can also try it, if possible, on a USB DAC if it has a power cord. The speakers will still be grounded via the rest of the system, so it's not unsafe, although it may not be best practice.

The TEAC DAC that didn't have this problem, might have been connected via an optical cable which obviously doesn't carry electrical signals and thus won't connect the grounds, or it could have had an internal opto isolator on the USB input. Then the USB connection is electrically isolated from the rest of the system, by converting the electrical signal to an optical signal and back again, thus breaking the electrical connection between the two devices entirely. Some of the better DACs have this. My Grace Design m903 had it for example, and I never had this problem while I used it. Bottomline: if you can, try to use an optical connection and see if that helps.

You won't see it recommended to disconnect the grounds in the power cables of devices, because a manufacturer or someone on the internet can never be sure that there is a connection to earth somewhere in your system. Therefore a grounded plug is fitted, and it is recommended to never lift the ground, just to be sure. But if you know what you're doing, you can lift the ground on one device, as long as it is grounded via another device.

As long as the wiring in your house has an RCD installed, you're pretty much safe from electric shock. Every leak to the outside, be it to ground or to your body, will instantaneously cut the power. It won't come to that, because you will make sure that one of your devices still has a proper direct ground connection (but the others will not, they will have an indirect ground connection!). By the way, if you have a cable radio or tv device in your system, it is likely that that cable provides a second path to earth. That is also something to think about when you're counting all the connections to ground.
One final thing: I have seen (but not used) audio interconnect cables with the shields connected only on one end of the cable. These may also help in such a case, but obviously will not link the grounds of two devices, so if you have such a cable and don't know about it, you may leave one of your devices without a ground at all.
 
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alxlwson

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Nothing should be "flowing" to ground. Ground is there as a safety, not as a path to 0.

Grounded cables are never supposed to be grounded on both ends except in very particular circumstances. That's how you end up with grounding loops, which can actually induce unwanted voltage into the conductor.
 
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B00nie

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A regular audio interconnect uses the negative lead as a shield so it must be connected at both ends in order to get sound. There are of course special types which have a separate shield. A cheap trick to try would be using an XLR converter box (meant for professional audio) that lifts your audio signal from ground. Use those to transmit signal to your speakers, IIRC the cost is like 20 bucks a box.
 

klm

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Nothing should be "flowing" to ground. Ground is there as a safety, not as a path to 0.

This is not true. Where I live, ungrounded wall outlets are still very common. Many devices with metal casings will have a voltage on their case, induced by their power supply, when they're connected to an ungrounded outlet. You can feel this when you touch the case with your fingers, our you can measure it with a DMM. This is drained when they're connected to a properly grounded outlet. It then flows to earth. You can easily try this yourself.

Edit: google 'leakage current' or 'smps leakage current' to learn more about this.
 
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alxlwson

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This is not true. Where I live, ungrounded wall outlets are still very common. Many devices with metal casings will have a voltage on their case, induced by their power supply, when they're connected to an ungrounded outlet. You can feel this when you touch the case with your fingers, our you can measure it with a DMM. This is drained when they're connected to a properly grounded outlet. It then flows to earth. You can easily try this yourself.


Good God...did you guys just get radio?!

What you've described is a very old and unsafe thing. Was the safest way to do it, though. Due to having a metal case, the case needs to be grounded. If your outlets don't have a third prong, then the second best thing was to connect the housing to neutral. That way, if line voltage ended up shorting to case, you didn't immediately become path to ground(still ends up working this way) and hopefully would open the breaker. In systems like this, you end up having a floating neutral because there is no earth bond on the secondary of the transformer in the power supply.
 

klm

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What you've described is a very old and unsafe thing. (...) then the second best thing was to connect the housing to neutral.

This is not what I describe. I am talking about SMPS leakage current. It has nothing to do with antiquated systems or house wiring, it occurs in a lot of modern electronics. This leakage current will flow to ground. Now we should get back on topic on how to prevent computer noises from entering your audio system.
 

alxlwson

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This is not what I describe. I am talking about SMPS leakage current. It has nothing to do with antiquated systems or house wiring, it occurs in a lot of modern electronics. This leakage current will flow to ground. Now we should get back on topic on how to prevent computer noises from entering your audio system.

It has everything to do with antiquated power system.

SMPS_schematic.gif
 

B00nie

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You should get a tech grade isolation transformer, run your computer and amp through that. No more buzz. Those can be found at moderate cost from Ebay.
 
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