Thought you did not care for the Blue? I don’t have an answer on either of these headphones for you, conventional wisdom dictates that these headphones are better suited for solid state or hybrid amps. Like most conventional wisdom that really does not mean jack shite, DNA amps excel at dynamic driver headphones that much I can tell you.
Someone with far more experience than myself can elaborate on why planar headphones can be finicky bastards. What I can tell you is any DNA amp and a Utopia is wonderful match, several owners of both items in this forum would be able to confirm this.
Internet never forgets… 