I've spent a while now using the ifi micro black label as a preamp to my sx1010, and can definitively say, this is the best I've ever heard my he4. Complete black background, insane instrument seperation, a very open but intimate sound. Just incredible. Right now I'm listening to, how to destroy angels- ice age. A song I've heard, I don't know how many times over the last few years. It's one of those songs that's so well recorded, and on the slower side, will sound good on anything. But, I've never heard it thus good. Granted, I never got a chance to run the sx1010 with the audio gd 10se as a dac, perhaps that'd be better, I don't know, but I also don't care. The ifi drives the he4 well enough on its own, it's seriously an amazing piece of gear. A capable dac, powerful hp amp, iem matching to get rid of hiss on sensitive iems, a pre amp, coax in, spdof in, actual rca out, USB in, USB to charge your device, all in a very small footprint for what it is. Absolutely a keeper in my rig.