I have a third generation iPod. It still works, so when its battery died, I replaced the battery myself. It still works well. However, this generation has a problem with sound quality due to low quality components used in the internal amplifier. So, I decided to make myself a decent amplifier to connect to the line level output of the iPod. I just had to build it into an Altoids case.
I based it on the popular CMoy amplifier circuit design, and it uses a stereo Burr Brown operational amplifier with high quality support components.
It sounds amazing, and I can’t wait till my new Sennheiser HD-595 headphones arrive. In fact, these headphones require an external amplifier. The iPod just won’t drive them.