Devialet 400 owners - Need some basic help setting up

Hi all,

After consulting with people in this forum on a good upgrade path for my amps, I decided to get the Devialet 400 and try something different.
I am getting them this week and wanted to be prepared with the right cables. Reading all the instructions I could find, I still don’t fully understand how to connect it to my setup, and was hoping someone could help me out.

I intend to integrate the Devialet into my home theater system, while also using it as a DAC for stereo music listening.
I know that this must be the most basic thing, but I am having trouble understanding how to connect the main two speakers to it:

I run a Marantz AV8802A as my HT Pre.
The Devialet needs to be connected to the Marantz.
The speakers connect to the Devialet.

The Devialet has 2 AES/EBU terminals which I thought were XLR (they look like it), which I planned on connecting to the Marantz L and R balanced outputs.
When I read the instructions on the Devialet website, it showed that the existing Pre connects to the Devialet using RCA cables that go to "Line 1".
What are the AES/EBU connectors then? What are they for?

I am then planning on telling the Devialet to Pass-through those to the Marantz so that I can control the volume using the Marantz when watching movies.

The second thing that I am unsure of, is what to do when I want to listen to 2-channel music, using only the Devialet. Do I just turn the Devialet on and have my sources connected to it directly?
What if all my sources are connected to the Marantz? Is there a way to keep them connected and still have the Devialet do all the processing?

Sorry about the basic questions, I just want to make sure that if I need to replace the balanced cables that I have, I will buy the right ones.

Thank you in advance for your time.

I hesitate to jump in here because I am not the most technical guy but my 400 doesn't have XLR connections. i recommend you use banana plugs for your speakers. It's kinda tight quarters. I honestly couldn't figure out how to hook spades up. As far as home theater goes, I don't have a clue. I am very pleased with the amps though. I doubt I will ever go back to the big heavy amps.