I am looking to replace my Chord Mojo in my office setup. I don’t like the hassle with the charger in our open space office and my very mobile working style in general. So... what would be a good choice for a small and portable dac+amp with only USB power? I have had the Dragonly Red and didn’t like it. Ifi idsd nano black is on my radar. Anything else in around max $500 range?