You're basically using the Fiio amp as a line-driver for the aux input on your head unit. Unlike car amplifiers, your head unit lacks a gain to attenuate the input. You have to be very, very careful that you do not overvolt the aux input, or you'll fry the circuit and potentially ruin the entire head unit.
Think of the system as plumbing. Voltage is the amount of water pressure you are putting into your system, and the amperage the volume of water passing through. Too much voltage and you'll blow the receiver and smell something burning, which is not a good thing.
I'm not saying don't do it, but to keep the volume on your headphone amp as low as possible, and turn it up slowly. As you hear distortion you are above the threshold of the input, and should back down.
Good luck,
Boz
Log in to comment