Hi-res audio can be a cruel mistress. You'd be forgiven for thinking two five-star products joined in union will surely bring high fidelity sound to your ears, but, as anyone who's connected a set of high-impedance IEMs to a hi-res DAP (even if it's one of the best portable audio players hooked up to some of the best wired headphones) knows, it's just not that simple.
Why? Because said player may not have the oomph or power to fire up your earphones' multiple drivers to their full potential, that's why. And that means you'll need a separate headphone amp (often bundled in with some of the best portable DACs), which may affect the sonic characteristics of your chosen player's onboard digital-analog-converter.
