I just need some clarification, is it the regular Fiio E9? or is it the E09? or the E09K? Because if it is the E9, I don't recommend using it with IEM's, as they have low impedance, and the E9 has a 10 ohm output impedance, and so does your soundcard, and the output impedance should be less than 1/8th of the impedance of the drivers, in which case the IE80 is 16 ohms, which could actually damage the drivers, if not just change the sound of it, to a loose, boomy and overpowering bass. If you were to get the IE80's, just use them straight out of your phone, if it doesn't get loud enough, get a different amp for them.