Can I connect my iPhone to my Ayre integrated amp

Probably the most important factor affecting the sound quality, beyond whether you use the headphone or the dock connector output, is the resolution of the music files, themselves.

Music in a lossless format is going to sound a lot better than the same music from a 128kbps mp3 file. I find, though, that the higher resolution mp3 files sound good enough given the fairly low expectations I have for the iPhone or iPod as a source. Of course, the higher the resolution of the files, the fewer of them you can fit on the phone.

Reubent - Yes, in my comments about music file resolution I didn't mean to imply you couldn't completely enjoy music at lower resolutions. I probably spend at least as much time listening to Pandora and Spotify as I do to the higher resolution sources I have.

The Pandora iPhone app is a marvel, giving you the music you know you like layered with similar music you had no idea existed, anywhere you have phone or wi-fi access.