AIYIMA Audio A2 Mini Stereo USB Gaming DAC Decoder Headphone Amplifier Converter Adapter for Desktop Powered Active Speaker - AliExpress
My (well, comparatively) budget setup. AKG K702s, Aiyima DAC-A2 and FiiO M3K. The DAC isn't great but it's a hell of a step up from the Macbook's headphone jack, IMO. Lucas amiibo