Oh wow, that’s very enthusiast friendly. I never got to try HE1 with another dac because connecting anything to HE1 was not allowed (local dealer that has since gone out of business). Someone connect some high-end dac to HE1 and post some experience.
at CanJam NYC eariler this year, Sennheriser was very good about letting me plug my AK player (with my interconect cable) to the HE1