Benchmark to amp direct question?

Skipping a preamp is just like adding one .
What I mean here is synergy . Just as preamps need to be matched to an amp , output impedence to input impedence , so does your DAC's output impedence need to match your amp's required input impedence range . Also , the quality of your volume control needs to be considered as mentioned above .

Good luck.

I wonder if the output impedance of the balanced outs suits your amp better than the impedance of the rca outs ?
Might be worth thinking about , for others , rather than accepting a blanket conclusion that one connection type sounds better than another .

What really matters is that you found what works best for you . Congratulations and enjoy the music .