Unshieleded ATX Power Cables

[Slender]

https://youtu.be/LDEOJtn1Cd8?si=al9rcTb0eANqZN2u

idk i had same issue with be quit 550 watt (if remember right) and the cables was shielded from that psu i think...they was not naked if remeber right and HDaudio cable too...

after i change to 700watt (be quiet pure power 11) then the issue disappear as in example video by slender (where i had exact same exprience with psu and could even hear this sound in my headhones and by my mouse movements) and even my gpu whine coil got lower on sound when under high power draw after switch to this 700 watt model...


@XEM

"The weird part was I was hearing my mouse's polling rate through audio port. 1KHz exactly, when I set my polling rate to 125Hz, it was a different noise."


can you record these sounds and upload here ? sounds it like white static noise from an old TV ? and how about USB audio ? you hear any inteference (white noise) sounds on high volume ?

same. im bought new psu 850w (superflower platinum) and usb dac and that sound is dissapear in my hp. But that psu give 500-600mv when start, and ~1500mv when fully connected.
my gf 650w have that weird sound but it ads only 50-100mv when start with full connected!

I am using Aerocool P7 850W Platinum PSU. I will try to record the noise but i already solved the problem by shielding HDAudio cable with aluminum tape. I will unwrap the tape for the sake of experiment. On my oscilloscope, 12V rail had ~20mv peak to peak ripple
at ~700 watts and 6mv PP Ripple on idle. 500mv ripple seems too much, I think that PSU is broken.

what oscilloscope you have, and can you provide photo of results, thanks

[XEM]

Hey guys, I am an Electrical and Electronics engineer and I have a deep understanding of EMI.

This summer I made a new setup and it had noisy 3.5mm HDAudio port, I was hearing electrical noise when GPU was pulling some watts.
Then I rerouted HDAudio cable, this time it was near CPU power cable. And whenever i was moving my mouse, i started to hear mouse interference sound.

So my unshielded HDAudio cable was picking up electrical noise and i was hearing that. I've never thought my 12V ATX power cables could act like an antenna, but they were.

I experimented with shielding my HDAudio cable with Aluminum tape, All the noise was gone. Now I am planning to Shield all of my ATX cables (GPU, CPU, 24Pin, sata etc.)

The weird part was I was hearing my mouse's polling rate through audio port. 1KHz exactly, when I set my polling rate to 125Hz, it was a different noise.

I think power draw of CPU slightly changes on each mouse polling, this causes power cables to radiate an EMI field, causing all kinds of problems, USB desync and etc.

Mouse inputs has very high priority for interrupting cpu , and polling use lots of cpu power, you are hearing that .
Any cpu demanding task will make these noises , prolly they wont cause interference with operation of perhipals

I think on each polling, Core is awakening from a deeper C state.

[XEM]

https://youtu.be/LDEOJtn1Cd8?si=al9rcTb0eANqZN2u

idk i had same issue with be quit 550 watt (if remember right) and the cables was shielded from that psu i think...they was not naked if remeber right and HDaudio cable too...

after i change to 700watt (be quiet pure power 11) then the issue disappear as in example video by slender (where i had exact same exprience with psu and could even hear this sound in my headhones and by my mouse movements) and even my gpu whine coil got lower on sound when under high power draw after switch to this 700 watt model...


@XEM

"The weird part was I was hearing my mouse's polling rate through audio port. 1KHz exactly, when I set my polling rate to 125Hz, it was a different noise."


can you record these sounds and upload here ? sounds it like white static noise from an old TV ? and how about USB audio ? you hear any inteference (white noise) sounds on high volume ?

I've never seen a PSU cable with proper shielding, many have just simple mesh sleeves to get cables together.

Even this cable is not properly shielded and they are ripping audiophiles for 75$. The shielding material needs to be grounded. I don't see any cables grounding the copper tape under the sleeve.
https://ghentaudio.com/products/pc03?VariantsId=15574

I am using an E-atx motherboard that has long pcie traces and 8 dimm slots. I am also planning to shield naked PCIE and DRAM lanes on the PCB. Just put some copper tape on naked areas of the PCB, solder a grounding wire to copper tape and here you go, hermetically isolated motherboard.

I am also planning to MOD the PCB with big tantalum caps, Escpecially VRM's and 12V Rails, basically every power rail that i can decouple.

[ablemor]

I only have floaty mouse movement, but when I used a magnet on the side of my computer case, it solved the issue. Why? Could this be caused by the ATX power cable?

[XEM]

I only have floaty mouse movement, but when I used a magnet on the side of my computer case, it solved the issue. Why? Could this be caused by the ATX power cable?

A magnet can actually alter the magnetic Permeability of differential-Common mode Chokes in the PSU, thus improving power quality.

A good quality PSU should come with 2-3 stage Differential and Common mode chokes, but most psu's don't even have them because they are expensive.

If you look for EMI filter on Aliexpress or Ebay, you should see something like this:

EMIFILTER.png (224.75 KiB) Viewed 1592 times

You can try these cheap EMI filters to filter powerline noise. But powerline noise is not that important if you are filtering 12V rails with good combination of Electrolytic, Film and Tantalum Capacitors. Also active compensation techniques improve 12V ripple levles very significantly.

In this thread, I am worried that Electromagnetic field created by PSU cable can induce a 10+ milivolts of noise on nearby conductors, thus causing all sorts of problems. This is way after getting a ripple free stable 12V rail.

[ablemor]

I tried using an EMI meter, but I didn’t feel any difference between 1500mV and 100mV. I also have a Greenwave EMI filter that works really well, but I haven't noticed any change. Only the magnet had an effect—maybe it’s still working, but it doesn’t completely eliminate the problem. What could be wrong? Should I optimize Windows? The mouse just feels floaty.