How does this compare with the Sound Blaster Audigy Rx 7.1 which is only 60$ and has a very high quality DSP?
Board architecture, layout, and construction techniques are more refined on the EVGA. Adding to that is the capacitors are far from the only component that impacts sound positively. I was unable to find a shot of the Nu Audio Pro boards. Looking at the older model and Sound Blaster Audigy Rx 7.1 shows some clear differences though.
Quite clearly you can see a lot more effort has been put into isolation and the inclusion of a heatsink. On the inside, the EVGA has a cover that passively cools and isolates from RF, vibration, etc that do impact a DAC. Basically they bear almost no resemblance to one another outside having similar connectors. One of these two sound cards looks like it was (over)designed by a guy who has 13' speakers and a few hundred grand worth of audio equipment in his office. Clearly they are aimed at different end users.
The Sound Blaster has design criteria more in line with using a 1500w PSU, dual GPU, a dozen fans, and OC'ing to the moon that all result in a very dirty ATX power delivery through the board. The EVGA will keep performing considerably better the more controlled an environment you create for it. The person using a 10Gbps card is likely to grasp how important isolation and regulation are and probably make better use of it. Both cards would work just fine, and we should be thankful quite safely nowadays, in either machine. Coming to appreciate the different purposes, looking outside gaming channels for reviews, and seeing what actual audio enthusiasts have to say could go a long ways towards understanding the best option for you.
I'm not familiar with the Sound Blaster software so won't make this any more lengthy attempting a superficial analysis.
In either case, playing a very well recorded flac/wav/DSD music file will be a rewarding experience compared to lossy mp3.