Hissing Noise from USB ouput of Intel NUC

I hope so, too!

Having a multimeter would let you test, if that NUC PS indeed has a protective earth to output ground connection, possibly causing a ground loop.

By the way, your ordered PS also has a three prong AC connection.
In almost all cases of such SMPS’s, there’s no protective earth to output ground connection, but there’s a power input side line filter, that absolutely needs the protective earth connection to properly work - that has nothing to do with user safety, but EMI emission regulations.

In my above described case, there was NO ground loop inducing the noise. It was the silent PC’s internal voltage regulation circuitry causing the problem, and the Intona properly, galvanically isolated that.

There, the usual culprit of audio ground loops is - that’s, why I explicitly asked!

Now, if the TV has an antenna cable connected to it - and one of your components has a protective earth to signal ground connection, which many power amps have - that causes the dreaded ground loop, because it draws earth from a far distant point to your AC outlet earth, causing voltage potential equalization currents.

So, have you also tested with antenna cable removed?

I should’ve also made it more clear you, to only connect the bare minimum amount of components to stream Roon while testing for your “hiss”, so leaving out any ancillary componentry like TV, step down, what not…

That NUC PSU does not seem to be the standard Intel NUC PSU? The standard Intel PSU does not have an earth connection…

At least, all my Intel NUC PSU’s here in the EU just have a two-pin connector…

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I don’t know how those Mean Well SMPSs are built, but for me they’ve been noise-free powering digital sources (Pi-based) plugged into a variety of DACs.

As I wrote…

… which would explain that there’s no ground loop induced.

But it very likely seems to be a different problem the OP is facing, which is that the…

Let’s wait and see, then.

@Fernando_Pereira @Marin_Weigel
I am not too optimistic that MeanWell power adaptor will eliminate the hiss sound… as the origin of electric circuitry noise is from Intel NUC

How did you conclude that? It’s possible, as @Marin_Weigel explained, but switching power supplies/regulators/grounding/main power can interact in a wide variety of ways. The only reason I suggested the Mean Well SMPS is that they are built for medical uses with some attention to residual noise.

From what I read few feedback from Intel NUC users at forum intel, like this one @Fernando_Pereira

but hopefully that’s not my case. My Intel NUC has worked flawlessly for nearly 18 months. Since I upgraded by amp to Accuphase from Krell, I observe this hissing sound.

Good question, I am not sure, it comes with the unit that I bought from IT online store.

Though it’s 3-pin, many occasion that i observe there’s no earth wire connect to the earth/ground pin.

I did a test last weekend with this 3-pin plug to an adapter without earth , there’s still hiss.

I have a quick check on my Intel NUC 8i5BEH, there’s BIOS update rolled out last year October, do you think I need to update BIOS UEFI ? Not sure will the update reduce the electronic noise a bit?

My Intel NUC is a dedicated 24/7 Roon Core, no other application except streaming music.

When I installed my ROCK in Intel NUC 18 months ago, I have updated BIOS during that time, do I need to update to latest BIOS and follow the following instruction again ?

After reading this Roon Core Machine NUC 8i3 BEH down after Bios Update BE0090.bio

I should skip the BIOS update.

U could just use a raspberry pi and connect it to your amp. Shouldn’t that get rid of all your issues?

When using unshielded ethernet cable - yes, likely

I think the problem described there is a physical noise from the NUC/power supply - not a transmitted audio signal.

So not your issue.

All my 8 gen NUCs are running 0089 bios without issue (I actually didn’t realise there was a 0090 but after seeing that post I won’t update - mostly because it isn’t needed)

So I think you can safely update to 0089 without issue - although I’d be amazed if that helps with your problem.

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Thanks for your advise and suggestion. My ROI from Intel NUC yet to achieve, let’s see the new PSU that I order if it will help a bit to reduce the unit noise. Will consider R-Pi only after NUC kaput.

Right, at least I found the culprit after a long trouble shooting, thanks to this good forumers assistance. Hope the new switch mode PSU will help reduce the electronic noise. The PSU is on its way from UK, will take around 6-8 weeks to deliver.

@MarcMarc Do you have Raspberry Pi setup as Roon Core or Roon Bridge ? I read Raspberry Pi is not compatible and one still need a mini PC of Window OS/ Mac OSX or Linux as Roon Core. I already have CVN X2 thus I do not think i need another network media player.

RPi cannot serve as Roon core. Bridge works fine.

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Bridge. Core is a M1 MacBook

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The Pi as a bridge might help - because your DAC would no longer be connected to the NUC core.

Ropieee is a very easy (and common) way to do this. All my endpoints are Ropiee Pis!

Roon recommend not using your core as an endpoint - see Rule 1 in the article below.

Although, sadly, Raspberry Pis are not easy to obtain at the moment.

Guys, I have a notebook, Macbook too, but i prefer a dedicated 24/7 mini pc to run Roon Core that’s why i chose Intel NUC for a cheaper solution.

With Roon ARC, I can access Intel NUC and music library remotely with ease but not my notebook/Macbook .

The root cause is to eliminate the hissing sound.

Even if i have roppie as my bridge, the hiss would still travel via this bridge to my DAC then Amp and speaker , wouldn’t it ?