+1 upshift
I have added a better DAC to my Bluesound Node a few times. In every case I got better sound, much better with the Denafrips Pontus 12 anniversary DAC (much like upshift had done with his Terminator II). You can also upgrade to an external linear power supply, which can also lower noise. Of course, in all things audio, upgrading to a much more expensive and better streamer will result in better sound. The Bluesound devices can get to a certain quality of sound for what they cost (just like any audio component). A new Corvette can be modified and souped up to outperform that basic model but it will not outperform a Formula 1 race car.