What Amir meant is that if your amp can drive to full power with as little as 1V (or up to 2V), you should not bother about any negative impact from the DAC, because, in that range of DAC output, the D10s performance is equal or better to the very best amps out there. Including crazy expensive...
If you want to connect the Genelec with a digital link (which makes sense), you can route a separate signal to them from a PC connected in USB (Multichannel mode) to the RME and connect the Genelec to the RME's AES out.
You won't have any control on the RME for this link: volume and any...
I think the AES out level would be fixed.
And not all Genelec have an internal DAC.
What you may do, for sure, is hang the Genelec to the Main 1+2 XLR out and the secundary system to the Phones 3+4 (with an adapter cable). You then would have 2 fully separated Stereo DACs, with dedicated EQ...
Stax Lambda. Loooooong time ago.
I still own the (relatively) inexpensive electret Stax SR44 I purchased in... 1979.
Other than that, my current Focal Elegia isn't cheap either. And I like it.
(Although the output level is too low when driven from the Yamaha DM1000 mixer headphones output. But...
RME ADI-2 Pro fs R - Mono Loopback
Loopback is cumulating DAC and ADC Distortion and Noise !
For 85% of the range between -1dBu and +24dBu, the loopback SINAD is at or above 113dB
To achieve this, DAC performance has to be better by some margin.
That's about what we try to achieve here:
The only way out of this kind of labyrinth is that every component is just (measurably) "clean" and transparent.
Otherwise its an endless puzzle.
That's why Amir started to measure speakers.
Transparent DACs and amps are easy to find nowadays and...
What he means by "insignificant" is that you won't hear (ever) any sound degradation due to the DAC.
That means it will perfectly do the job.
You may find your amp's specs here:
Input 2-5 (line) input sensitivity = 210mV at 47kΩ
Maximum input 2-5...
As the Brio is an integrated amp, you just need a good USB DAC with fixed volume.
I'd give this one a try.
Don't be fooled by the price: look at the measured performances!
You may spend the remaining money on a Roon lifetime license, as an example.