Gunbei
The issue with the sound quality of your iPod may have as much to do with the integrity of the files on the iPod as it does with how you're getting your music from the iPod to your system.
You didn't say in your original post whether you're compressing the files and, if you are, by how much. An uncompressed or lossless file is likely to sound pretty good coming out through the dock as a line-out signal. In that case the quality of the sound is limited only by the quality of the digital to analog converter in the iPod.
If, on the other hand, your music has been compressed to 128 or 160 kbps, as most people do for their mp3 files, you've already thrown away enough data that there's no getting it back regardless of what you use to move it from the iPod to the system.
The issue with the sound quality of your iPod may have as much to do with the integrity of the files on the iPod as it does with how you're getting your music from the iPod to your system.
You didn't say in your original post whether you're compressing the files and, if you are, by how much. An uncompressed or lossless file is likely to sound pretty good coming out through the dock as a line-out signal. In that case the quality of the sound is limited only by the quality of the digital to analog converter in the iPod.
If, on the other hand, your music has been compressed to 128 or 160 kbps, as most people do for their mp3 files, you've already thrown away enough data that there's no getting it back regardless of what you use to move it from the iPod to the system.