"Ultra-low distortion AAA™ circuit with high-voltage swing"
I feel like people might be overlooking this important point. The current low-cost THX amps (789, 887, SP200) suffer from compression due to a lack of voltage swing. I currently have the SP200 (which apparently has the worst compression of the three amps, so take that with a grain of salt) as well as the Asgard 3, and the Asgard drives my HD 660S headphones way better than the SP200. Sure, there's a bit less detail and the sound is a little warm, but with the Asgard I get much better dynamic range, slam, soundstage, and imaging. The ONE amplifier could actually end up sounding better than the 789 (at least for dynamic-driver headphones) and would almost certainly be a better alternative to the Asgard 3 at this price point (depending on your preferences and power needs).