Advice

A lot better IMO. If you reduced the jitter of the source by using a quality USB converter and a good power supply. Also you could also eliminate a ground-loop by adding a good 1:1 signal transformer between the DAC and the integrated amp.

Beyond that, you would have to change out the DAC.

Steve N.
Empirical Audio

Step by step is the best way to go. As suggested, first ditch the Mac DAC. USB 3.0 outboard DAC's are in the pipe line and that will make a difference. It will also give you a path to further improvement.

+1 to what Zd542 said. If it 'sounds great', walk away and spend your money elsewhere.

The law of diminishing returns hits early and hard in this hobby. You could spend a fortune chasing the ever elusive 'absolute sound', or you could just be happy. The choice is yours.....choose wisely.

Look at your room . bass traps have never had a negative impact on any system i have ever heard . If you are a diy type at all they are simple to build . And it will save you at least half off of new.Search superchunk bass trap if you are at all interested in learning about them. In my experience some room treatment has had a bigger impact than switching amps and pre's in the same price range . Good luck !

Nice system. My advice would be to try a new DAC, the Cambridge is good but there are certainly better.

Many of which you can try risk free in your home.