iPod 2.0.1: Poor Sound Quality From the Dock‘s Line Out Port

If the USB 2.0 cable is connected to the dock, any compressed music files (such as .mp3, or .wav) may have poor sound quality if you listen to them using the dock's line out port.
Symptom

The sound quality from the dock's line out port is poor.

This happens when the dock is connected to your computer using the Dock Connector to USB 2.0 + FireWire cable, and the equalizer (EQ) is turned on.

Solution

Use one of these solutions:
Published Date: Feb 18, 2012