Push and hold the volume dial for 1/2 s.

The SETUP menu has a switch option, too.

On the IR Remote, yes.
Assign a button in the SETUP / Options / SPDIF/Remap Keys menu.

I don’t have my ADI-2 handy for the exact steps, but the menu is self-explanatory, kind of.
See also manual page 27, 28.

Currently I just can tell you how to set it in the RME ADI-2 Remote app.
The device’s hardware SETUP menu has similar entries.

• Device / Phones / Dual Phones: Enable (not sure this is needed)
• Device / Phones / Toggle Ph./Line: PH 1/2
• Device / Phones / Mute Line vs. Phones: PH 1/2 (not sure this is needed)
• Device / Hardware / Remap Keys: IR Remote
• Device / Hardware / [select a key to assign]: Toggle Ph/Line

It’s a bit tricky to understand the (existing!) logic behind the interacting menu entries in this section, but it’s possible to get what you want.

So it’s already assigned, nice.
Don’t see this mentioned for the IR Remote in the manual.
Couldn’t check here, don’t have ADI-2 with me.

Kais, MstrC-117 thanks!

Det ville vært flott hvis det var noen forum regler på hvilket språk som var standard her. feks engelsk. Ikke tysk som må sies å være en nisje i resten av den vestlige verden. Slik blir svarene søkbare i forumet og andre kan også lære fra og ta del i diskusjonen på en fruktbar måte.

Denne blandingen av språk er arrogant og utimelig mot nåværende og fremtidige kunder av RME´s sine produkter.

Er det i det hele tatt noen som modererer dette forumet, og som har baller nok til å sette noen standarder for dem som fremsetter svar og spørsmål. For eksempel å bli enige om et språk dette kan bli gjort på. @MC

Ingen oppegående mennesker gidder å krabbe gjennom de hakkete svarene fra google translate for å komme til en løsning.

And if that translation was correct: there is absolutely nothing 'arrogant' on asking a question in German in the forum of a German manufacturer.

Again, this site is hosted in Germany, it's TLD is German, it belongs to a German company, run by German people, a significant portion of members here are also German. I see no issue and no offense with German language here, despite not being a German speaker myself. Yes, it probably would be a better practice to stick to the OP language in every thread (be it English or German).

The only issue I see with that post is it hijacks the thread and it would be better for the user to create a separate thread (or even better, not to create any thread, since his question already had taken care of in the user manuals of his gear and in this forum, and using the search first is considered a good manner on any forum).

ADI-2, even more so the Pro versions, are of high and unusual complexity.

The manual favorably covers all that and more in a comprehension I’ve never seen elsewhere.
But- for a non-technical person or just someone who’s new to it, the amount of information given can be overwhelming.

I think, part of the value of this forum is to give cookbook-like advice to handle certain situations.
I don’t hesitate to do so.

For a forum search one needs a certain awareness what to search for - even that can be out of scope.
I by myself sometimes can’t find my own entries, so have a collection of links for quick answers to repeatedly popping-up questions.
E.g. I never found again an early post of mine where I A/B-ed ADI-2 Pro and ADI-2/4 Pro SE, as if it had disappeared.

I think a person who is aware of RME, studio monitors, AES interface and all that stuff is technical enough to be able to look for the relevant trivial and straightforward instructions in the supplied user manuals. Even more so, to use the standard search function on the forum

BTW, I purchased the ADI-2 Pro back in 2021 exactly in order to have a digital connection to my then-new HEDD Type 07 MK2 speakers, otherwise I would probably had settled for the ADI-2 DAC

Don’t worry, it’s usually not that way here.
Feel free to ask any questions.

@MstrC-117 might have been a bit over-enthusiastic on his “Lederhosen-“idea - a cliché that can be seen as allegorical at best.

As Germans we really don’t like some of the expressions used, they are outdated and abandoned for almost 80 years now.

There are BTW, in fact no secrets about RME devices, not even hidden functions.
It’s all in the manual, and we are here to help you all to find all necessary information.

No, please do...