External DAC?

I typically just leave the volume on the integrated amp (which has balanced input; Marantz doesn’t seem to have it) at about 9. It can be controlled from a remote but very ergonomically, so it is simpler to adjust volume from the (great) remote that now comes with the RME ADI-2 DAC FS. I sometimes also adjust balance, a control that my MF M6si does not have. Volume is changed in the digital domain so it’s perfect. Withe the remote you can also dim the display which is a great feature. This DAC is great with my beyerdynamic headphones and IEMs!
I don’t remember my settings for balanced vs RCA but can find out that discussion
https://forum.rme-audio.de/search.php?search_id=657718769

I found it: "I just changed line out reference level to +1dB, as XLR out adds 6dB, to achieve the recommended +7dB"

So for balanced, I use +1 dB out ref level (higher levels were leading to distortions). I don't use line out any more but the ref level was higher. It is important to get this right!

If you lock or set the volume to fixed on the RME can you still use the EQ features? IMO that is one of the best features of this unit. 

@prashanth13485

your settings are correct i believe, it is how i used it

you want the auto level working at max db for max effect, it uses the full dynamic headroom of the akm dac chip set that way

In my case (Musical Fidelity amp) the settings have to be different between RCA and XLR. RCA setting was pumping too much voltage into the amp and reducing headroom. At first I thought that the balanced cable I used was to blame (for RCA I used AQ Colorados, that I don't need anymore since I switched to XLR). Finding the correct setting brought the sound to perfection. I think the Marantz (in spite of its price doesn't offer balanced in)