Well it's not as easy as it should be.And...? Is one objectively better? You'd hope so for the price difference.
Firstly The Sabaj has a nice display and easy menu system, so beats the Mojo there, and has both an unbalanced 3.5 output as well as 2,5 balanced output. I recently bought a balanced cable for both the Denon and the HD600 so I could test the balanced output out, and it made a noticeable improvement to the HD600 in particlaur.
Once I level matched, the Mojo in Line out mode is quite high (3v), then they are closer then they should be at the price difference. The Mojo is a better but the Sabaj highlights how the Mojo has a rolled off treble and more (false) weight in the bass. That extra weight (and it creeps in to the midband as well) does make the Mojo not very suitable for complex dense music, imo, but there's no doubt it has a "nice" sound.
I'm thinking of doing a change in this downstairs system and thought I'd give the two a play while I do some saving. It's given some serious food for thought.