Soundflower + AU Lab + Mavericks results in incessant clicking
Soundsiphon solved it for me as well. You do not need to buy the pro version, because the capturing of whole system audio (which means no specific application like safari needs to be selected as an audio source) is for free. :-)

My setup:
soundsiphon as default system audio device:


any Audio player/source on OS Yosemite -> AU Lab 2.2.2 (IN soundsiphon -> Waves GEQ -> OUT FiiO DAC:


Sorry for the german screens :-)