To me the DAC is the signature component of a digital system and easy to hear the differences. Just had a guy bring over a PA Audio Directstream MK2 DAC to compare with my Chord Dave. Both are FPGA but from different continents. Differences were obvious.
You may have to listen a few minutes using songs you are very familiar with. If you stil can't tell the difference, you may need to work on the rest of your system. Make sure you use good cables, but even bad cables should reveal differnces.
Jerry