Lumin d2

It will depend on the connected equipment. XLR is what we use with the LUMIN Amp when at trade shows, but sometimes the 'balanced' nature of XLR isn't always carried through the amplifier in the same way. At home I just use RCA and it sounds fantastic.

(Associated with LUMIN)

Mine smp is the gato 400s balanced input

Hard to tell as I don't have any experience with that brand and they don't talk much about them.
Balanced is theoretically better though, so definitely worth borrowing some cables if you can to compare.

Yes i give it a try