Maybe you can record the noise and post it here with a short video - might help to solve the problem.

Here is an example of showing a bug from a different  company with a little video: https://youtu.be/Bf38cKJ6NBc

That is indeed a ground problem. You need to connect the DAC to a good earth/ground potential, as it happens when you connect it other, properly earthed devices. The Pro can also show this issue, but as you might have realized from your own statement 'only on the IEM output' it won't be as obvious over there.

If your power strip (and the rest of the power net) does provide grounding then it might be enough to plug the router or the ADI's power plug or both reversed. Experiment a bit.

> different power outlets, rooms, grounded power strips

...don't qualify as grounding the ADI. The ADI's power supply is ground-free, so wherever you plug it in there is no ground connection to the ADI's housing.

> If I touch the ADi-2 dac with my hand, the noise seems to decrease.

The ADI is connected via USB to your computer which should have a three prong power connector and provide ground to the ADI. Obviously that doesn't work, or ground in your power outlet is either missing or contaminated.

For a valid test try to connect the ADI to something that is guaranteed to have ground, like radiators or water lines.

BTW, is the noise also there when you remove the USB connection?

You might give this a try (see link below).  Only requires very, very basic skill.  It completely solved a similar noise/grounding issue using an UltraRendu streamer powered by an Uptone LPS-2 power supply, with the UltraRendu connected by USB to my ADI-2 DAC FS.

https://audiophilestyle.com/forums/topi … grounding/

Thanks @rpgroman for the suggestion. I'll take a look into it.
@MC, thanks a lot for your input too. Changing the Isoground setting of the iUSB3.0 didn't make a difference.
Could you please elaborate your suggestion a little bit? Connecting the DAC to a radiator or water line, you said.

Hi,

I just tried your wire suggestion. Unfortunately, it didn't make any difference at all. The same type and amount of interference noise were present.
I also tried my in-ears in the Phones output using an adapter and I don't notice any noise at all. Only the IEM output seems to be picking these interferences from the router.
I happen to have a wifi extender in the living room (not where the DAC is plugged currently), so i connected it in the same power strip and, again, I get the same type of noise.
I am not particularly savvy with all this electrical stuff, so any further input would be highly appreciated.
Is there any chance that the IEM output of my unit is not properly shielded? Or is it definitely an issue with my setup?

Thanks again for the help.

You mean without the wire thing, right?
If I put my two hands around the IEM, the interferences are reduced actually...
And also, if I touch the in-ear plug when plugged to the IEM output, the noise goes away, so you might be onto something there.
If there is any chance that there might be an issue with the unit, I would prefer to send it for a check up to have some peace of mind.

I thought I'd tack on to this thread as I had an almost identical issue when using IEM's and I thought I'd solved it by replacing the power supply - the interference seemed to vary depending on where the unit and power supply and wires were placed, so I moved the unit and swapped the SMPS for a more shielded unit (check the "Just a few questions from a beginner thread). However, I had it all wrong.

The problem wasn't the power supply, or the placement of it or the unit. The problem was the cable I was using on my IEM's. When I moved the unit and changed the PSU the problem went away but what I'd failed to take into account was that I'd also had to add a short headphone cable extension to reach my seat. Earlier today I plugged my IEM's straight in and the interference was back again. As I went to unplug them I noticed the noise went away when I touched the metal 3.5mm plug housing. Touching other parts of the unit or grounding it to a pipe make no difference, it's actually the cable itself.

The differences between the stock cable and the aftermarket cable are really quite minimal. The aftermarket is thicker and nicer to use but there's certainly no difference in overall sound quality. However, it has quite a large straight steel jack rather than a moulded 90° plastic 3.5mm. Perhaps there's a difference in the wiring too, I don't know. I have three of these aftermarket cables and they all behave the same.

So now the problem is solved, I can either use a short extension (mine is just a Sony extension with plastic connectors I got with another pair of headphones) or just swap my IEM's cables back to the originals. If you're still hearing interference try adding an extension or swapping out your IEM's cable.

It's not a problem I've ever run into before. In retrospect I think when I was moving the PSU, wires and the DAC around I was also moving my head around - the aftermarket headphone cable seems to work as an antenna unless you ground the plug with your finger. There you go anyhow, if you're getting interference out of the IEM output then it's worth trying different headphone cables if you can, or an extension if you can't.

I'm glad it helped you, Sindri, it drove me nuts trying to nail down exactly what the cause of the interference was. Actually I still don't really know exactly what the cause of the problem is, only how to address it!.

Why certain IEM cables pick up interference and need grounding is beyond me, but it's a bit frustrating having to swap out cables when you go from another device to the RME. I'd just leave an extension plugged in but then the unit doesn't automatically recognise and switch over to phones settings when you plug into the full sized jack. Barring automatic switching, I'd like a setting to manually switch not just between line out and phones, but line out, phones and IEM mode - then I could leave short extensions plugged in and not only cure the interference issue, but also reduce wear on the sockets.

Just another gentle nudge - I'd still love to able to prod the volume knob for mute, it just makes sense to me for a volume knob. Keep the long press for switching between phones and line-out (and IEM!), it's handy if you use it, but a quick press for mute would be useful. It obviously can't mute it in all menus, but when the unit is sat on one of the main screens it's the intuitive option. Or maybe either the treble button or bass button could be assigned to mute rather than them doing basically the same thing? It seems wasteful to use one of the four assignable keys to mute when there's three other buttons available, especially as when you do that the mute function is doubled up on the remote because the unit and remote's custom keys are linked. They could do with being seperate, with a few more options too (cycle custom EQ, crossfeed, balance left/right, bass/treble - maybe cycle/up/down/left/right with volume - just some things that are handier when you're sat back and need to tweak. It's pretty much the desktop king as it is, but RME don't strike me as the kind of company to say "that's good enough". I'm hoping the squeaky wheel will get the grease when it comes to the next firmware update