# USB or motherboard interference noise



## Tactus (Feb 2, 2021)

Hi folks. I’m experiencing some sort of interference through my speakers. It seems to be quite a common issue, but I just can’t get rid of mine, it’s most likely a motherboard issue. Here’s a video of what I’m experiencing:









						USB_Interference_Noise.mov
					






					drive.google.com
				




I’ll post my build at the bottom of this post. I use this mainly for audio production, which is my job. I use USB audio interfaces (at the moment an Arturia Audiofuse and Soundcraft Ui24R). Here are things I’ve done to try and combat it:

- Using the motherboard out of the case
- Taking all PCIE cards out
- Unplugging all case connections from the motherboard
- Trying different power outlets with different combinations (I have just moved flat and still have the same issue)
- Trying different cables (USB and speaker - balanced/unbalanced)
- Attaching a ferrite clip onto the USB cable
- Power conditioners
- Unplugging all USB connections and using the motherboards’ line out into a mixer

I’ve managed to get rid of the noise when I use a Hifime High-Speed USB Isolator, but it’s very unreliable and recently the second one I’ve had finished like the first one: the USB interface doesn’t get recognised when plugged in through it anymore.

The noise only comes out of my speakers. Recorded audio in through the interface and listening on headphones plugged into the audio interface don’t have the noise.

Even with my speakers off I can hear the noise coming straight from the motherboard only with the audio interface plugged in, and disappears when it’s unplugged. This issue only happens with my Aorus Pro Z390 machine and doesn’t with my Macbook plugged into the exact same setup.

Please help.….

Build:
Hackintosh with Mojave installed
CPU: i9-9900K
Motherboard: Z390 Aorus Pro
Cooling: Scythe Ninja 5
RAM: Corsair Vengeance LPX 32GB (2x 16 GB) 3600MHz CMK32GX4M2D3600C18
Hard Drive: ADATA XPG SX8200 1TB
GPU: Asus GeForce GT 710 2GB GDDR5
Power supply: be quiet! Pure Power 11 CM 600W
Case: X-Case 4000 Big Open 4u
Inlet fans: 2x 120mm Noctua NF-S12A PWM
Outlet fans: 2x 60mm Noctua NF-A6x25 PWM
Wireless/Bluetooth: fenvi T919 for macOS PC PCI BCM94360CD
Keyboard: Logitech K760
Mouse: Apple Magic Trackpad 2


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## Ferrum Master (Feb 2, 2021)

Get a UPS with pure sine function. That's the first must, to get rid of random AC pollution from your neighbor devices. You prolly have ground problems at home, even if you have it may be set up wrong, polluted, exceeded device leak from Y caps and Active PFC's  etc modern times, modern problems.

USB has a lot of flaws and this is one of them. The end device power supply floats. If no common grounding is possible such rail noise will creep in. The PCB wiring is made in such manner, that it pick ups EMI in one end or another. With two devices a noise loop forms and the noise gets amplified. It is actually always there, with decent grounding it gets tamed, and low gain, high current like headphones, you will not even hear it, but high gain, low Z input... things get wild. You may create a common return path if the audio interface has a screw, and you can ground it, so the noise should take the shortest path through the wire.

I have also tried USB isolators, but they are buggy. Try very short cables. I actually killed my Hifime fast. Use cheap ADUM IC based now, like for Bluetooth or RTLSDR, it cleans noise floor and you get wastly better SNR, you can see it using SDR wave capture, how drastic the change is using plain USB and with a isolator, same applies measuring audio.

If you have options, use SPDIF... there are super expensive optical USB cables too, they work, but the cost.


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## DeathtoGnomes (Feb 2, 2021)

Ferrum Master said:


> Get a UPS with pure sine function. That's the first must, to get rid of random AC pollution from your neighbour devices. You prolly have ground problems at home, even if you have it may be set up wrong, polluted, exceeded device leak from Y caps and Active PFC's  etc modern times, modern problems.
> 
> USB has a lot of flaws and this is one of them. The end device power supply floats. If no common grounding is possible such rail noise will creep in. The PCB wiring is made in such manner, that it pick ups EMI in one end or another. With two devices a noise loop forms and the noise gets amplified. It is actually always there, with decent grounding it gets tamed, and low gain, high current like headphones, you will not even hear it, but high gain, low Z input... things get wild. You may create a common return path if the audio interface has a screw, and you can ground it, so the noise should take the shortest path through the wire.
> 
> ...


Ground problems are a huge factor in older homes (pre-70s), homes that still have 2 wire house wiring including 2 prong outlets. A UPS would certainly help there.


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## Tactus (Feb 3, 2021)

Thanks a lot for the replies guys. I may have a look into a UPS since you both mentioned it, although I feel like it's not the best solution if I'm to be constantly charging one since I'd be using that all the time instead of mains power.

I did a lot of the electrical wiring in my previous flat, and am sure there was good grounding there. It's odd that this issue persists at two different flats. It somehow leads me to believe it's an issue with the computer. I've been using a real short USB cable, and you weren't joking about the optical USB cables, they are pretty pricey!

I'm going to carry on troubleshooting, but am running out of ideas. Gigabyte got in touch saying I should send the motherboard back and get a new one, which would be hassle, but could even come to that if I can't fix this issue.


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## Tactus (Feb 4, 2021)

The issue is sorted! Thought I'd post it here in case it would help anyone else.

I have put a DI box between the audio interface and the speakers and the ground lift on the DI box has sorted it right out. I'm using an ART DualZDirect but I'm sure any other stereo passive DI box would work, you can find the box here: https://artproaudio.com/product/dualzdirect-dual-professional-passive-direct-box/

Totally buzzing (in the sense that I'm happy, no more actual noise buzzing) now that it's sorted. Thanks again to @Ferrum Master and @DeathtoGnomes for the replies, much appreciated. Big ups!


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## Ferrum Master (Feb 4, 2021)

It will help. Passive isolation transformer. But it degrades audio quality, no matter how good they are. It may be acceptable. Measure up.


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## Tactus (Feb 4, 2021)

Cool. In what way will it degrade the audio quality? I'm intrigued. I'm currently just happy I can actually hear proper sound through my speakers again!


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## Ferrum Master (Feb 5, 2021)

Tactus said:


> Cool. In what way will it degrade the audio quality? I'm intrigued. I'm currently just happy I can actually hear proper sound through my speakers again!



It seems you are quite new into audio scene and technologies. 

Read up this one and catch on. It has signal loss depending on frequencies and also distortion. Depending on the device quality, you may need to implement compensations. Do loopback measurement. Don't you calibrate your setup, leveling before you do any recording?



			https://www.jensen-transformers.com/wp-content/uploads/2014/08/Audio-Transformers-Chapter.pdf
		


This is a workaround anyways. You should fix your electricity problems at home, it may emerge at some other points too.


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## mateusfig (Aug 8, 2021)

Tactus said:


> Hi folks. I’m experiencing some sort of interference through my speakers. It seems to be quite a common issue, but I just can’t get rid of mine, it’s most likely a motherboard issue. Here’s a video of what I’m experiencing:
> 
> 
> 
> ...


I got this kind of problem with my audio computer, right after it suffered eletrical damage in all USB 2.0 ports. I can't use the 2.0 ports and only can use the 3.0 spare port. This boring noise change even when I move the mouse. 

Note: My USB DAC wont' relay noise through my amp with my laptop!


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