I've used a Hifiman adapter to do so. I set the digital volume near minimum on my pc at first, get a little volume with the amp, then slowly bring up the digital and turn down the speaker amp if needed. With the Hifiman Adapter meant for 50 ohm he-6, the speaker amp will still be looking at a high impedance load with the Eikon. Not all speaker amps may survive this. My Anthem 225 does well. But not a lot of point. High impendance, dynamic driver headphones are best with high voltage potential tube amps. Actually, I like my hard to drive planars typically current hungry, with tube amps best also. Greatest dynamics. HE6 out of speaker taps of Mogwai with Hifiman Adapter and Abyss right out of Aficionado, these tube amps have some decent current flow..