I can speak from driving the Eikon & Atticus, which are also 300 ohms. The main problem I had was volume for louder listening. It can be too low depending on the song and especially if you are using Mango EQ as well. You will get better overall performance from a desktop amp that can drive them more sufficiently. Maybe someone else with an HD800S can provide actual input. I think 300 ohms is the upper limit for the DX200, which is why I bought the MDR-Z1R instead. It drives them much better with little noticeable difference from a desktop amp.