@gpixels ,
As your DAC is inside of your integrated amp, you won't be able to upgrade, unless Hegel introduces new firmware.
As DAC and streaming tech is moving at a rapid pace, I have no doubt that much of what is now 'state of the art' will be bypassed by newer tech.
That being said, you'd need to spend a bit more money to get a significantly 'better' DAC than what you now own.
I plumped for a Brinkmann Nyquist, and I find it to be quite capable- so much so, that I consider it my last purchase for quite a while.
Bob