troubleshooting Computer PSU causing buzzing through active monitors?

[Doomguy]

I'm having an issue with an electrical buzzing noise coming out of the tweeters of my active monitors, I'm trying to determine the cause so I can fix it (ideally without having to resort to ground loop isolators). 

On Monday I received a new JDS Labs Element II DAC/amp unit to replace my dying Audio GD NFB 15.32. The Element is USB only, where-as I was using an optical cable with the Audio GD. Upon changing over to the Element, I noticed a 'dirty' buzzing sound coming from the tweeters (JBL 305P MkIIs) that was not there before. This buzzing is totally independent of the volume pot on the Element or volume in Windows. It ceases when I switch to headphone output on the Element or when I turn my computer off. 

Additionally, this buzzing behaviour is not present when I plug the Element II into other devices. I've tested it with two laptops (a dell and a macbook air) as well as my android phone. 

The noise seems to correlate with system load (it becomes considerably more pronounced when running a game, sounding sort of like coil whine) but also changes in pitch when I move the mouse and takes on an even buzzier sound when I use the scroll-wheel.

I'm not electrically knowledgeable, so please enlighten me if I'm totally mislead on this, but if this buzzing was a regular good old fashioned ground loop issue, wouldn't it still occur even if I had the element plugged into a different source? FWIW; everything in my system is plugged into the one power-board, which is plugged into the wall via an extension cable. 

I can only conclude, with my layman lack of knowledge and the process of elimination I've done so far, that it's an issue with my computer since it's fine with the laptops and phone. When I think about what could be wrong with my PC to cause this issue, my mind immediately goes to my power supply, which has made a buzzing noise when running since the day I bought it last year. Does it make any sense that a bad power supply might cause something like this? If it does, I'm strongly considering buying a new different PSU and cross my fingers that it fixes it. It's not too risky as I would return my current one anyway (I've just been too lazy to do so and it hasn't appeared to have caused or been related to any real issue until this).

Sorry for the wall of text, would appreciate any insight or thoughts on this!

tl;dr - Active speakers buzzing since getting JDS Element II. Buzzing seems to be correlated with PSU buzzing. Speakers do not buzz with other computers used as source. 

[Wembley]

That's a good level of fault finding to start.  There are several elements unique to what I assume is a PC as opposed to the laptops you tested.  My first guess is that the issue is actually EMI from various elements in your PC being caught somewhere in either the USB chain or sound processing.  The reason that is my first thought is that the load on a power supply isn't likely to vary radically  with minor system changes such as a mouse wheel scrolling.  That doesn't eliminate the power supply as either the source of the noise nor of being a link for noise generated elsewhere.  I don't think it's a straight mains power ground loop, which I would expect to have a relatively stable noise character.  Your noise is apparently being generated or modulated by your computer use.  

 

Have you tested the laptops operating of both battery and with connected to the mains power and charging?  I've found laptops can be electrically quiet when running on batteries but provide more interference when connected to mains.   Also can you run the USB DAC from an external DC power supply such as a battery pack?  If you can isolate it from the mains that may help to determine whether the noise source is related to mains power or earthing.  

 

Don't overlook something as simple as unplugging your mouse (and any other USB devices) while testing the DAC on the same interface.  There is a small chance it's generating some noise as well if it's cheap.  Stranger things have happened!

 

If you do end up getting a new power supply, I'd be interested to know whether it fixes the problem.  

 

 

[PCOWandre]

I recall having horrible noise problems on a batch of cheap cases in the 90s. Hey, they were $40 with a power supply, bargain, right? Pity they could take out AM radio reception for the entire house.

 

So that's one way PCs have traditionally emitted clouds of noise. The other one can be just lack of proper grounding and EMI control. Especially with home-builds that miss some of the finer grounding details. Make sure all the screws are in, no slot covers missing, all the motherboard screws in properly (grounding around the CPU power supplies on the motherboard can have a noise ipact). 

 

With a PC, the noise can bleed from anywhere and everywhere, annoyingly. Make sure there are no loose cables acting as antennae. Try a different USB lead in case the shield/ground is bad on the one you're using.

 

Ideally, turn off and disconnect everything but the PC (box alone). If that isn't noisy,  add back keyboard, mouse, monitor (bad HDMI lead bleeding noise?), etc. If it is noisy, trying another power supply isn't a bad idea at all.

[Doomguy]

Thanks for the input, guys. It's appreciated!

Current update is that I got a ground loop isolator and a new (longer) USB cable. The latter made no noticeable difference to anything (other than allowing me to place the Element where I wanted) but the former had some interesting results. Let's just say that it didn't really fix the buzzing but rather moved it elsewhere. Before I had the isolator, my speakers would buzz when the pre-out mode was selected and the noise would disappear when the headphone out was selected. Now it's the opposite! They're fine when I'm actually using the speakers and start making the buzzing noise when I switch to headphones! I'm not really sure what to make of that or it's a hint for what's going on, but if it means something to anybody, please tell me!

When I get some time (and can be arsed) I will do as you suggested, PCOWandre, and try to turn off / unplug everything and try it all 1 by 1 to see if there's something in particular that is causing this. I suppose if I have everything else unplugged and off rather than the PC, and the noise is still there, that would lend some viability to my PSU theory, but certainly not confirm it.

Wembley, regarding the laptop being plugged in, I did indeed try having the Dell that I tested plugged into the Power Board that I run everything else off, and it was dead quiet. No noise. I also did indeed try unplugging the mouse, but the steady buzzy, scratchy noise was still there. Out of curiosity, if it is EMI, do you think chucking ferrite cores on a bunch of my cables would help?

At the very least I can use my speakers for listening without annoying noises, for now, but I'm looking forward to getting to the bottom of this. 

Edited August 16, 2020 by Doomguy

[gwurb]

It could indeed be your computer power supply. What make and mode is it?

 

Also, how long is the cable from your DAC to your powered speakers? What does it run past?

[Tweaky]

16 hours ago, Doomguy said:

Thanks for the input, guys. It's appreciated!

Current update is that I got a ground loop isolator and a new (longer) USB cable. The latter made no noticeable difference to anything (other than allowing me to place the Element where I wanted) but the former had some interesting results. Let's just say that it didn't really fix the buzzing but rather moved it elsewhere. Before I had the isolator, my speakers would buzz when the pre-out mode was selected and the noise would disappear when the headphone out was selected. Now it's the opposite! They're fine when I'm actually using the speakers and start making the buzzing noise when I switch to headphones! I'm not really sure what to make of that or it's a hint for what's going on, but if it means something to anybody, please tell me!

When I get some time (and can be arsed) I will do as you suggested, PCOWandre, and try to turn off / unplug everything and try it all 1 by 1 to see if there's something in particular that is causing this. I suppose if I have everything else unplugged and off rather than the PC, and the noise is still there, that would lend some viability to my PSU theory, but certainly not confirm it.

Wembley, regarding the laptop being plugged in, I did indeed try having the Dell that I tested plugged into the Power Board that I run everything else off, and it was dead quiet. No noise. I also did indeed try unplugging the mouse, but the steady buzzy, scratchy noise was still there. Out of curiosity, if it is EMI, do you think chucking ferrite cores on a bunch of my cables would help?

At the very least I can use my speakers for listening without annoying noises, for now, but I'm looking forward to getting to the bottom of this. 

I recently had a very similar noise problem with my IK Multimedia iLoud MTM active speakers.

Strangely it could be dependent on what software I had open at the time.

Anyway, my situation was with a PC recording studio, which uses a audio interface which the speakers plug into, and which you also plug headphones / mic's /guitars etc, and like you every time I moved a mouse the noise would start and vary in pitch.

 

You haven't mentioned what cable you are using into your active JBL's. I assume it's the balanced XLR connection in you configuration......the speaker cables could be a big part of the problem.

 

Anyway, after ripping some hair out trying to workout WTF was causing it I went to the Sound on Sound magazine forum [Po Audio magazine] and found that' it's a pretty common problem with active speakers.

Recommended fixes were to run the speakers off a separate power point, which I did, and it did lessen the noise a bit, but TBH it was a small difference.

 

FYI at first I was using mono jack plugs into my MTM's from the interface, after reading up on the problem [It IS a grounding problem you are suffering] I went to Jaycar a bought some stereo jack plugs [even though each speaker is only getting a mono signal] and made up some new cables using  2 core shielded MIC cable .

https://www.jaycar.com.au/2-core-screened-professional-microphone-cable-sold-per-metre/p/WB1530

 

If using balance XLR cables, you might want to unscrew the plugs at each end and check that the ground wires are connected properly, or if feeling bored with lock down, build a set of new speaker cables using the same type of cable making sure that the wiring is correct on you XLR plugs.

Anyway, after I ran the new shielded stereo cable from the interface to the speakers, that made the noise go down a LOT.

 

But the final solution was to isolate the USB from the interface to the PC by running it through a pro level USB hub, this killed all but the very last vestiges of the noise [I have to put my head up to the speaker to hear it now]

https://www.macfixit.com.au/anker-usb-3-0-superspeed-10-port-hub/

This USB hub has a huge power supply and is well built, and basically the ONLY one recommended by those who are doing a lot of computer based music production.

 

I just looked at a picture of your JDS Labs Element II DAC/amp and see it has single L&R  RCA out, so I guess you are using adapter plugs of one type or another to connect to your JBL's. XLR or Jack plug.

It would appear that your situation RE cabling is the same as mine was when running the mono jack plug ended cables....insufficient grounding and shielding on the cables going to the speakers...hence the noise.

Although it does seem strange that you didn't seem to be having this problem with your previous setup.

FWIW I had the same problem when trying to hook the PC/interface to another HiFi system using adapters, mind you that was before I made up the new cables.

 

Edited August 17, 2020 by Tweaky

[Herbs]

I had the same problem, its the power supply, changing it probably wont help. 

 

Was your laptop running and off battery? Plug it into the wall socket see if it comes back. I did that and yup PC or laptop were the same, went away when you unplug the laptop cord

 

What did help me was an ifi micro usb 3.0, theres other products that clean USB noise, or don't use USB

 

Really cleaned up the noise for me no hum or buzz anymore

Edited August 17, 2020 by Herbs

[PCOWandre]

The only way these problems ever get diagnosed is through a process of elimination. And geez, for less than the cost of the iFi magic box one could buy USB over fibre kit and be done with it.

[Luc]

I have small active speakers(tiny wee things) with a built in dac that  are fantastic but I wanted to listen through my main speakers and system using various amps. So I connected line out on the PC to the amps. I have the exact same noise as OP, mouse movements, scroll wheel and buzzing and bacon frying.

I've just build a brand new gaming PC and the hope was there that the 8 year difference between old and new PC might fix the problem with the mobo having better shielding and the psu but...nope, not one bit of difference, exactly the same annoying noise. I can turn the onboard audio to zero and the noise is still there. Tube amp/SS doesn't matter the noise is still there.

I was thinking that seeing as my little active usb connected speakers are silent then maybe it's the built in dac that is stopping the noise? My PC is grounded to the best of my knowledge. 

So ideas, along the line of a dac in between the pc and the amp and/or a fully shielded cable from pc to amp which is close to a 10m run in my case might help.

 

My little active speakers are reviewed here if your interested>> Innosound Picollo

 

I'm fresh out of ideas and it seems  no one's come up with a solution yet and plenty of people do have this problem as there's been a few discussions here over the years.

If you've got it then you'd know it's annoying as F.

Would love to find a solution.

[PCOWandre]

34 minutes ago, Luc said:

So I connected line out on the PC to the amps. I have the exact same noise as OP, mouse movements, scroll wheel and buzzing and bacon frying.

PC line-outs are just horribly noisy in my experience. Even the supposedly fancy line-outs on my Alienware laptops have been too noisy to use. This is probably why there's a huge market for cheap USB DACs out there; even the very cheap and cheerful avoid the noise that bleeds out of everything inside the case. Newer PCs seem to be way, way worse than the old-school -- I recall not having noise problems in the 90s with a Gravis Ultrasound. The 3.5mm jack can probably go a little high-resistance as well; I recall soldering RCAs onto the aforementioned GUS to deal with that.

 

Your speakers -- which look very tidy -- escape noise on two levels -- by not taking any analog signal from the PC, and by having the DAC right next to the amplifier and thus not having interconnects to pick up noise either. 

[Doomguy]

On 17/08/2020 at 1:54 PM, gwurb said:

It could indeed be your computer power supply. What make and mode is it?

 

Also, how long is the cable from your DAC to your powered speakers? What does it run past?

It's a Corsair HX750i, so it's certainly not cheap crap by any stretch of the imagination, being 80+ platinum, fully modular etc.

They're 3 metres long or so, they only run past other cables and sort of just hang around behind my desk.
 

On 17/08/2020 at 2:43 PM, Tweaky said:

I just looked at a picture of your JDS Labs Element II DAC/amp and see it has single L&R  RCA out, so I guess you are using adapter plugs of one type or another to connect to your JBL's. XLR or Jack plug.

It would appear that your situation RE cabling is the same as mine was when running the mono jack plug ended cables....insufficient grounding and shielding on the cables going to the speakers...hence the noise.

Although it does seem strange that you didn't seem to be having this problem with your previous setup.

 

 

Yeah I'm using RCA to TS cables as the JBLs don't have RCA inputs. 
I was under impression that this unit only having USB was a big part of the problem as JDS labs themselves recommend on their FAQ / troubleshooting page to use optical if having this sort of issue, where possible. I was using optical with my old Audio GD which I'm guessing is why I didn't have this problem until now?

On 17/08/2020 at 5:56 PM, Herbs said:

I had the same problem, its the power supply, changing it probably wont help. 

 

Was your laptop running and off battery? Plug it into the wall socket see if it comes back. I did that and yup PC or laptop were the same, went away when you unplug the laptop cord

Yeah I tried plugging the laptop in the power strip in during my initial testing and it was as silent as when running on battery.

---

So earlier today I unplugged everything from the computer and from my power-board and just had the tower, element II and monitors running. The buzzing noise was still there, so it's something inherent about the PC itself. Possibly the PSU like I originally thought, but who the hell knows. Trying to figure out that will be rather time consuming and likely costly.

After that, I decided to try plugging one of the monitors into a different outlet from the next room with an extension cable (The room I'm in only has a single dual outlet) and voila! No more noise from the monitors with either pre-out or headphone out on the Element!

So, what I'm going to do is order a long extension cable and route it as neatly as I can along the skirting and door frame, slip it under the door in the corner into the room and have a separate power board for my JBLs. I think it's fair to say that this is the simplest and cheapest solution that has no sound quality compromise the way the ground loop isolator does (which didn't even fix the problem anyway). Kinda sucks that this will be an ongoing consideration for when I next relocate that I'll need to have 2 separate outlets to plug my setup into, but that's a bridge I'll cross when I come to it. At least I've killed that bloody wretched noise and can properly enjoy this audio upgrade!

I'm still considering replacing the power supply anyway since that noise it makes doesn't seem right. If I do, I'll try plugging my speakers into the same power board again and see if that was indeed the cause.

Appreciate all the input, guys! 

[PCOWandre]

Just checking -- does the noise go away with the USB cable disconnected but everything else still plugged in and turned on?

 

[Herbs]

1 hour ago, Doomguy said:

I'm still considering replacing the power supply anyway since that noise it makes doesn't seem right. If I do, I'll try plugging my speakers into the same power board again and see if that was indeed the cause.

I use a 300$ corsair PSU for my PC, the sounds you describe are the exact ones I had even with a high end PSU, what fixed it foe me was USB conditioning 

[gwurb]

You get the noises when you plug the computer and the speakers both into the extension cord (via powerboard or double adapter)? Just to rule out that it may be the circuit in the computer room.

[davewantsmoore]

On 09/08/2020 at 6:59 PM, Doomguy said:

The noise seems to correlate with system load (it becomes considerably more pronounced when running a game, sounding sort of like coil whine) but also changes in pitch when I move the mouse and takes on an even buzzier sound when I use the scroll-wheel.

Driver/interrupt issue on the computer.

On 09/08/2020 at 6:59 PM, Doomguy said:

I can only conclude, with my layman lack of knowledge and the process of elimination I've done so far, that it's an issue with my computer

Correct.

On 09/08/2020 at 6:59 PM, Doomguy said:

 I'm strongly considering buying a new different PSU

Not the issue.  It's just configuration.

[Ittaku]

One question, is the computer on a different power circuit to the active monitors?

[Doomguy]

20 hours ago, PCOWandre said:

Just checking -- does the noise go away with the USB cable disconnected but everything else still plugged in and turned on?

 

Yes, the noise ceases when I disconnect the Element's usb cable.

18 hours ago, gwurb said:

You get the noises when you plug the computer and the speakers both into the extension cord (via powerboard or double adapter)? Just to rule out that it may be the circuit in the computer room.

Yeah I tried this, the noise is as normal, so it seems to be directly related to them being plugged into the same circuit?

6 hours ago, davewantsmoore said:

Driver/interrupt issue on the computer.

I don't really know what this is or how to fix it. What could I have configured wrong to cause something like this? Could it be something as simple as not installing a particular driver?

 

----

 

So it seems I actually spoke too soon yesterday  There is still some noise coming through the speakers when connecting them via extension to the next room, it's just fainter that it was before. I shouldn't be too surprised as the outlet I had them plugged into is in the exact same spot as the one I'm using in my PC room, just on the other side of the wall. They must be connected in some way. 

So, I decided to try the outlet on the other side of that room, which does indeed seem to cut the noises down to imperceptible levels. However, it does seem to cause a steady deeper buzzing sound. Not sure if that's related to the crappy old power-board I'm using or the amount extensions being used. In any case, that outlet is just too far away for it to be feasible for me to run permanently.

Just as a sanity check, I reconnected my old Audio GD NFB15.32 with optical to my PC again, and plugged in my monitors back to where they would normally be plugged in; nice and quiet again, no weird electrical issues, just the faint amp hiss of the JBLs through the tweeters. 

I'm starting to get frustrated at this situation, as I really don't want to spend much more of my free time trying to fix this problem. I'm seriously considering cutting my losses with the Element II and looking for another DAC/Amp solution that has optical in, and maybe if it's extra insurance, a balanced solution. My speakers do have XLR inputs, maybe it would pay to use them.  The Topping DX7 Pro is certainly a possible solution which I did consider before getting the element II, but I had decided against it due to its somewhat high headphone output impedance.

Edited August 23, 2020 by Doomguy

[Herbs]

You wont get the noise with optical, its a USB filtering issue

 

 

[PCOWandre]

I just looked at the Element II and I can see it has a pair of RCA inputs -- what are these connected to? 

[Doomguy]

5 minutes ago, PCOWandre said:

I just looked at the Element II and I can see it has a pair of RCA inputs -- what are these connected to? 

Nothing, they're there as analog input for the amp, if you want / need to bypass the DAC for some reason.

[PCOWandre]

OK, I'm just looking at noise ingress points. Is there a difference in noise level when you switch from the DAC to the RCA inputs?

[Doomguy]

On 25/08/2020 at 8:50 PM, PCOWandre said:

OK, I'm just looking at noise ingress points. Is there a difference in noise level when you switch from the DAC to the RCA inputs?

There certainly is, I used the Audio GD as a DAC and fed the Element II a RCA signal from it. No noise at all from the speakers. From what I've read this is because the Audio GD while using optical input is galvanically isolated which stops the ground loop noise from being able to occur the way it can via USB, or something like that.

At this point I've conceded to throwing some money at the problem to solve it, which I'm happy to do at this point as I'm totally over messing around with it. Fortunately, it doesn't have to be that much. I'm going to continue using the Element II as my headphone amp as I really like the unit for that purpose, but I'm going to buy a standalone DAC to fix the problem with the speakers; the recently released Schiit Modius. At $199US it seems a hell of a value to me. It uses the same DAC chip as the Element and according the AudioScienceReviews it measures similarly well, if not very marginally better. It's got 4 input options, including the optical that I'm really after, but the big selling point is that it's balanced! It has both RCA and XLR outputs, which can be use simultaneously.  So my plan is the use the Modius to feed the Element II a RCA signal for my headphone, and XLR to my active speakers (with a passive monitor controller for the volume duties). I think that ought to be all the insurance against ground loop issues that I'll need. 

When I get the modius I'll actually be quite interested to see if I get the same noise issues using it with USB and RCA to the speakers, and then see if the XLR on its own is enough to fix it. 

[Herbs]

6 hours ago, Doomguy said:

When I get the modius I'll actually be quite interested to see if I get the same noise issues using it with USB and RCA to the speakers, and then see if the XLR on its own is enough to fix it. 

I'd put money on it you will with USB, optical you won't.

[blybo]

I see the OP is buying a new dac, but would an optical USB cable filter the PC noise? Something like this?

 

https://www.amazon.com.au/MonopriceFiber-SlimRun-Extension-Optical-116379/dp/B01N94D03E?th=1

 

My quick googling doesn't find shorter than 10m lengths, but surely shorter options are out there.

[Doomguy]

3 hours ago, Herbs said:

I'd put money on it you will with USB, optical you won't.

With RCA I'm sure you're correct, but I'll be mostly interested to see if XLR deals with noise itself. 

2 hours ago, blybo said:

I see the OP is buying a new dac, but would an optical USB cable filter the PC noise? Something like this?

 

https://www.amazon.com.au/MonopriceFiber-SlimRun-Extension-Optical-116379/dp/B01N94D03E?th=1

 

My quick googling doesn't find shorter than 10m lengths, but surely shorter options are out there.

Yeah they seem to be hard to find in shorter lengths and reasonable prices (from what I can tell the entire point of them is to transmit USB signals over longer distances), but I don't even know if it would even work for my purposes, and buying the DAC has other utility benefits anyway.