Sounds like something might be wrong with your shadow, or... you might be more sensitive to hiss than others. I am one of those people and am annoyed, very annoyed by hiss which spoils the clarity of even loud music.
The headphone out has nothing to do with the hiss if you set it properly. The headphone out put should be set high (about 90%) if you are going to amp it, then set the gain of the amp much lower and there should be no hiss at all, at least nothing more than a LOD.
If you wanted the truth, the iPod's headphone performs some things better than the best LOD and line out does. But, it also is more fidgety. For an iPod touch, keep wifi off with the LOD - it will cause interference which isn't detectable if you use the headphone output. Good luck.
The headphone out has nothing to do with the hiss if you set it properly. The headphone out put should be set high (about 90%) if you are going to amp it, then set the gain of the amp much lower and there should be no hiss at all, at least nothing more than a LOD.
If you wanted the truth, the iPod's headphone performs some things better than the best LOD and line out does. But, it also is more fidgety. For an iPod touch, keep wifi off with the LOD - it will cause interference which isn't detectable if you use the headphone output. Good luck.
