I just bought a pair of HiFiman HE-400's and they're amazing. I have a FiiO E7 DAC/AMP and though they do power them, I feel I could get MUCH more out of these cans. I heard that the FiiO E17 could power them really well, and I thought why not pair it with the E9K. Does anyone know how this sounds with the HiFiman HE-400's? And yes, I am aware that they are pretty easy to run. I just feel as though I could get MUUUUUCH more out of them with a better amp and DAC.