In the end, I sold the North Star. It was quieter with a balcker background, but it was a bit recessed in the mids. Conversely, the bass and mids of the ECD-1 were fuller and more satisfying--in some cases by a lot. The North Star had a better sound stage, but the ECD-1 was more musical and euphonic, especially with guitars and female vocals. The ECD-1 is a bit more congested than the North Star, which I attribute to longer decay and a higher noise floor with the ECD-1. In a way, I think the ECD-1 has more "flaws," such as some glare in the mids and the aforementioned congestion, but I found it to be the more musically satisfying DAC. However, I also could easily live with the North Star if I had to. I think it's a fine DAC.
Now in-house are the ECD-1, the HR UDAC, and the Dodson DA 217 mkII. I'll start a different thread.
I am now on to the