This amplifier takes input from a digital music player and boosts the signal for a richer, stronger signal. If you've got high end speakers, this device is a wonder - you'll hear parts of the music you've never heard before, and you'll never go back. For clarity, strength, and increased frequency response, try the PHA15. It's equipped with a mono 3.5mm male jack for input and a single speaker output. Requires a 12 V connection.