I've already made other suggestions to the person seeking an amp for the HD 650 (Bottlehead Crack, I'll toss in a suggestion for the Millett Hybrid too), and even answered the very question you just asked previously (on the same page too). Forums never change; when one person offers a different opinion that is not positive, people get super defensive and often to an irrational extent and start berating said person with irrelevant, totally off topic questions. People are allowed to declare that so and so product is unbeatable for a price, but when one suggests it is not the end all be all solution, that's when problems start! One of my major points earlier was that I fail to see a technical reason for the Ember II costing 3x more than a Schiit Magni 3 (being able to auto bias different tubes will add some cost but not 3x). Keep that in mind when considering the value of the Ember II.