CMA400i is a great combo with DT1990 , I don't have experience with the jotunheim. But for me I did go from a high end audio interface from Antelope. And this is more pleasing to my ears, I feel it is hard to describe amps and dacs if its not something that colors the sound much. It got power and its a solid all in one package. I love it with the DT1990 and my other cans.