@velomane - you are allowed 2 Roon Perfect Setups so setup the secondary with the output to the XLR ACTIVE in the GUI WEB MENU. No need to do any measurements. Alternatively, you could also activate the XLR preamp output on Room Perfect profile 1 and just switch it to bypass mode. Whichever you choose or think is more simple. Turning Roomperfect off via bypass while XLR Preamp mode is enabled or creating a 2ndary RoomPerfect Profile with no measurements and also with the XLR Preamp outputs enabled. In this instance you would switch between Roomperfect profile 1 or 2 and have bypass engaged even though it’s sort of moot since you would not have stored any mic measurements anyway for that headphone profile. Hope this helps you out.
As far as output level you are allowed variable or fixed output gain settings and also gain compensation settings. Since you wish to use the headphone amp's volume control set it to fixed on the Lyngdorf.
As far as output level you are allowed variable or fixed output gain settings and also gain compensation settings. Since you wish to use the headphone amp's volume control set it to fixed on the Lyngdorf.