Heard one of these amps at a meet yesterday, belonging to @Ninja Pirate . He had it hooked up to RME ADI-2 pro and it was very impressive. Lots of clean power, not sterile or dry sounding. Smooth, fast, detailed. Could use with hd800 or he6. The number of amps that work with both are few and far between. Did it drive he6 to its fullest capabilities, the best I've ever heard it? No, but it was 85%+ of the way there. Without going BW2/Rag it's the best headphone amp I've heard it with. Meet conditions etc etc, but warranted a further look, so I have one of these in the mail for further testing. Massdrop shill / hype train ftw.