Originally Posted by Flyingdog02
Also, forget to mention if it wasnt obviouse. Pairing the two together just makes a very strong headphone amplifier/DAC basically boosting the power of the E17
I understand what you are saying, but that might be perceived wrong.
Pairing the E17 with the E09K doesn't actually boost the power of the E17. It just means you will be using the E17's DAC with the E09K's headphone amp. That might or might not make much difference, depending on the headphones you are using and the volume you like to listen to. And for low impedance IEMs and headphones (16 ohm or 32 ohm), the E17 alone might be a better choice because of it's lower impedance output.
For the cost of the E09K and E17, there are better sounding audio setups if one doesn't need portability because you are paying for redundant hardware with that FiiO setup--two headphone amps,each with preamp capability. And if all you need is a portable option, there are better portable DAC/headphone amp units.