If Lumin T2 is your only source.
Using XLR out ( Lumin T2 ) to XLR in ( Hegel )
Can you use RCA out (Hegel ) to the new HP amp. ? May be.
But
You can use RCA out ( Lumin T2 ) to the new HP amp.
You can use USB out ( Lumin T2) to the new HP amp.
You can select the Lumin T2 out put with the app.
I think , the fewer gears , the better.
I have Lumin X1 , but I have not used it for a while. I am posting by memory .
Good luck