Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A must-have for external speaker systems

When I play my ipod or nano through my separate computer speaker system, I always use the pocketdock. Not only does it boost the volume by, what seems to me, about 30%, but it also cleans up the sound.Conduct the experiment of listening to your speakers through the ipod headphone line out jack, then listen to them by running the sound through the pocketdock attached to the bottom of your ipod. The difference is chalk and cheese. This is achieved by by-passing the headphone jack amplifier.A great product for little money.