Hi,
I use my Cowan iaudio x5 60gb to connect via the mini dock's audio line out to my home receiver. Everything on my mp3 player is FLAC. I noticed that the overall volume that the receiver puts out is lower than say if it would be coming from the radio, or cd player. To compensate, I have to turn up the receiver's volume. I was wondering if this is an indication of audio quality loss, or if it's just simply a matter of adjusting the receiver's volume since the mp3 player's output is not strong enough... Thank you for taking the time to answer this.

The output level from "consumer" music components is quite variable; there is no closely followed standard. The actual signal level of any device is not an indication of circuit or audio reproduction quality.