[rishan]

Hi all,
I know his has been asked before, and I've spent 3 days attempting the various solutions to no luck yet (and some bad luck with cables being mini-b instead of just mini.) I'm providing a ton of info in the hopes of proving I've done my research and someone knowledgable can decipher this easier.
Audio Chain:

1. 2015 Macbook Pro -> Fiio X7 as DAC Only -> SMSL SP200 -> LCD 2 Closed Backs
2. Brand new AMD 3900x, Asus X570 Strix-I, 2080 GTX Super, Corsair Platinum SF750w Powersupply -> Fiio X7 as DAC Only -> SMSL SP200 -> LCD 2 Closed Backs

Issue: On System 2 higher amplification levels with no music playing, I can hear noise. It gets audibly but mildy worse when scrolling or moving the mouse. It gets WAAAAAY worse when running a GPU stress test i.e. working the GPU hard creates mega noise.
I'm well aware both the underlying noise, and the Nvidia video card stress issue is well reported and many solutions have been proposed, however, they have worked very rarely and intermittently.
On System 1 (Macbook) there is ZERO noise with the same chain and amp maxed on high gain, on every USB port. Same for when it's plugged in and charging with less than 100% bettery OR if running just off the battery. Even more to investigate EMI, i literally put my laptop on top of the PC and still no noise. To take it one stop further, I ran a GPU stress test (which creates insane noise through any of the X570's USB ports), confirmed the noice on the X570, put the Macbook ontop of the X570, reconnected the chain to the Macbook and ZERO noise.
If it helps, running the amp out of the X570 line out provides the same noise.
Reducing the clock speed, memory clock speed, and power draw on the Nvidia GPU has no effect on the underlying base motherboard noise, but reduces the additional noise added when the GPU is under load.
So it seems the X570 motherboard is creating noise internally, this noise is made worse through stressing the GPU somehow and transmitting them the ports at the back. I'm using a Ghost S1 case, so no USB or audio ports at the front for now, but it's one of my favored first things to test.
I'm a maths/stats nerd and know nothing about electronics. From what I have read this is either a grounding issue or an EMI issue.
Trying to eliminate them one by one:

1. When testing System 1 and System 2 they are plugged into the same power strip yet exhibit noise vs no noise, furthermore, the power strip has a grounding light that clearly lit. I've tried another power strip too of course, same results. Both strips take input via a 3 pin USA plug and output the same way.
2. With having the chain plugging into the Macbook AND stressing the GPU on the PC, then putting the MacBook on top of the PC, still NO noise from the macbooks USD output. I'm not familiar with how EMI works, but if the Nvidia card was causing "non-physical" EMI this should have surely created noise on the Macbook chain less it's magically shielded?

Another interesting element, the noise starts when I boot the X570, when I'm in the bios for example. This means it's very unlikely to be a driver issue.
Given my limited understanding, it seems the motherboard is creating noise and passing it through all ports (USB and Line Out) and I've only noticed it now because I like me some heave Bass EQ with Heavy Amplification.
My proposed solutions:
- The X570 has an internal USB 2.0 header (all the ports on the back are USB 3), buy a short cable to connect to this internal USB 2.0 port/header and my DAC. I've heard that USB 2 ports sometimes solve this noise issue through a slower data rate.
- My next option is an externally powered USB hub then some kind of data only cable from the USB hub to PC I guess? This way the Fioo DAC would only get power from the hub which should be cleaner?
- Next option is to sell the FIOO, I prefer my ES100 + CIEMS over LDAC anyway and get a cheap self-powered DAC - any recommendations?
- Buy some kind of noise filter for the USB port on the back of my PC, but I'm skeptical because if it's ANC it will introduce delay, they are pricy and will it compensate for the noise from the Nvidia GPU card? I've heard a USD Galvanic Isolator might work.
- I ordered a AWG24 plus ferrit core shielded cable but it unfortunately didn't have the right mini-usb end and well I didn't expect it to work tbh give the above;


I'd appreciate any and all input.

 

[Raketen]

Description reminiscent of an internal ground loop issue (maybe with some EMI thrown in to boot though I don't think this is as likely since the DAC is external and not replicated in the Mac setup)? Do you still get noise out of your pc's own headphone out (tried driving amp straight out of that also?) You might be surprised how well those ferrite choke cables can work, at least I have had luck in past on a noisy laptop but YMMV.

Have seen positive reports of people using those USB isolators. (I recalled LLAT did a video specifically about using one for his case of GPU noise - sounds like you are generally fine using X7 or ES100 but if you were thiking of getting a DAC just for your PC anyway some of those iFi ones have their isolation product built in IIRC)

 

[rishan]

To clairfy: I used the Fiio X7 Mkii as a DAC for both the PC and Macbook to keep things as close as possible. If this was your assumption, are you saying there is a ground loop issue in my PC? It's very possible because it's a tight fit in the Ghost S1 case. Does the fact that the power stip have a ground light lit up in green?

 

[Raketen]

To clairfy: I used the Fiio X7 Mkii as a DAC for both the PC and Macbook to keep things as close as possible. If this was your assumption, are you saying there is a ground loop issue in my PC? It's very possible because it's a tight fit in the Ghost S1 case. Does the fact that the power stip have a ground light lit up in green?

Sorry missed part anout using mobo LO. So you don't normally use a USB DAC but you get the noise on both mobo LO and usb dac?

AFAIK these audio affecting ground loops are generally caused by internal pc circuitry which AFAIK is more or less isolated from AC mains by the power supply so the power strip probably isn't a concern* though the pc power supply itself might be involved (then again I don't really know what I am talking about). Things like that iFi usb gadget I linked basically do what you were proposing to do with the usb hub, seperate a USB port's data from the system bus power and allow you to attach an external power supply... that should not cause audio latency but I guess that wouldn't solve the mobo LO issue either? (this could be any number of things... PC building forums might have some groudloop troubleshooting guides).


(*I believe that the power strip ground light should always be on to verify that your wall outlet has a good ground? But I am not sure and it might be different depending on the manufacturer. )

coincidentally a similar recent thread, last post seems to have some experience https://www.head-fi.org/threads/how...hat-exactly-am-i-hearing.927116/post-15501865

 

[bigshot]

Didn't read your post too closely because it was an alphabet soup of acronyms representing a bunch of boxes plugged together and too many words, but in general ground loops aren't things that you are necessarily going to find a simple solution for. It's a bugaboo that takes a lot of trial and error to fix. You can try earthing the chassis of your various components with a grounded wire to try to determine the culprit. But it could be more complicated than that. Odds are, the problem is your PC. If you have the MacBook, why not just dedicate that to music?

With this sort of thing, the more black boxes you plug together, the more likely you'll be to have problems and the harder problems are to chase down. Adding external power supplies and expensive power strips and handy dandy noise filters are fine if they work, but odds are, they won't and you'll end up with just one more level of useless complication. The solution isn't more equipment, it's less.

If you're serious about audible sound quality, it's really easy to put together a simple system that works great and sounds great. You have the start of that with your MacBook. That and a headphone amp is likely all you really need. I know simplicity is an anathema at Head-Fi, but it is a virtue regardless of what equipment fetishes want to believe.

Your MacBook running off batteries will be pretty much immune to earthing issues. It will also produce sound quality that exceeds your ears' ability to hear. Your only concern is the impedance of the headphone jack and whether that is matched to the headphones you want to use. Solve that and voila! problem solved.

 

[rishan]

Appreciate the advice guys.

A couple points - I just tested the mobo line-out to see if it had the same noise and to add to the evidence that it's coming from the Mobo.

I do like this PC as my home workstation so I'm thinking my two best options:
1. There's a USB 2.0 header on the mobo, buy a header to actual USB2 port (which is supposed to be cleaner) and add the ifi noise cleaner
2. External powered DAC and data only USB cable
3. External powered USB hub and data only USB cable to Fiio

 

[NA Blur]

9 times out of 10 it’s the power supply in your system. One fix is to try another power supply from a different manufacturer or try to find a way to ground the power supply’s ground more effectively.

Some folks simply ground the chassis of their PC to a standoff on the motherboard and call it good. That is probably the quickest thing to try. Simply trim and attach a cable to a screw on your PC case ( must be a bare metal part ) and run the other end of that cable to a metal standoff on the motherboard.

Let us know if that fixes your issue.

 

[bigshot]

If the Mobo is the problem, ditch it. But if it’s a ground loop problem, it could still be anything else in the chain, not necessarily the mobo. The most likely culprit is the PC. See if you can get the same noise using a different source than the PC and then you can eliminate it.

 

[bigshot]

By the way, if you live in a modern building, by code the center screw that holds the faceplate on your wall sockets has to be grounded. Connect a wire to that and touch it to the chassis of your PC and see if it helps.

 

[rishan]

By the way, if you live in a modern building, by code the center screw that holds the faceplate on your wall sockets has to be grounded. Connect a wire to that and touch it to the chassis of your PC and see if it helps.

Really cool idea - would it have to be like a totally naked wire? I know nothing about electronics per say, would there be anything long lying around that might do the trick (I'd try randomly but don't like the idea of starting a fire in West Hollywood haha.) e.g. would a lan cable somehow work?

 

[NA Blur]

Yes a LAN cable will work if you don’t mind destroying it to do this fix. Cut open the sheathing, cut of the ends, and grab a wire. The wire you grab doesn’t matter and leave the sheathing on the individual wire you pull out. You won’t start a fire if all you do is run a ground from the socket center screw to your case. No need to fully remove the socket cover plate either. Just unscrew the center screw a few turns, strip the ends of the wire, and attach it to the screw and then a screw on your case. I doubt this will fix it as your PC’s power supply already has a ground plug.

Does your PC plug into the wall with a 3-prong plug?

 

[rishan]

Thank you sir, going to try this today.
Yes both my PC and AMP (SMSL 200) have three prong plugs.

Quick question for clarity, if the Macbook is plugged into the same power strip as the PC, yet the MacBook to DAC to AMP produces 0 zero at max gain, while the PC produces base noise and more noise on mouse clicks or when the GFX card is strained, does that mean the house grounding is completely fine and it's totally a grounding issue inside the PC?

 

[bigshot]

Most likely, yes. The PC is the lead suspect.

 

[NA Blur]

Basically yes!

 

[NA Blur]

Do you have optical out on your PC?