I finished the build and I am listening right now with a pair of DT880 600 ohm cans. I would love to hear some HD 800s, but alas... I was amazed at the clarity and resolution. I listened to Take Five and the drums and cymbals were great. I listened to Kokomo by the Beach Boys and I could distinguish each voice distinctly. Then I listened to a piano piece and I could hear each string. I have never heard that before. Then I listened to myself from an album our church produced to see how many mistakes I made. Wow, this amp even makes me sound good. The kit was easy to build. All the resistances and voltage were almost identical to the ones in the manual. I built this for my boss' retirement gift and hate to give it up. I think he will be pleased. Very nice Bottlehead!