My comment stands for over-ear headphones as well - it's just not going to matter for 90% of users. An Apple dongle is usually more than enough. I have several

My comment stands for over-ear headphones as well - it's just not going to matter for 90% of users. An Apple dongle is usually more than enough. I have several different amps, a tube pre-amp, several DACs and a Qudelix 5k DAC. I regularly switch between an HD600, HD650, HD560s, HE4xx and Audeze Maxwells. I can maybe count on one hand when I thought one combination sounded "better" than another, although I'm sure I could bump up this number if I tried. The problem is 90% of the time it just doesn't matter. There's loads of resources on the net that talk about this, e.g. https://www.youtube.com/watch?v=K8zAko5G6eg https://www.youtube.com/watch?v=K8zAko5G6eg Most of the time the differences are not that important, unless, as the adage goes, you're using the music to listen to your equipment rather than using the equipment to listen to your music. Which... 90% of users don't do.