Designed to take your Grado headphones (pictured here with the RS-1 headphones) to new sonic heights. Machined from a solid block of Mahogany, it derives its power from two 9-volt batteries, good for 40-50 hours of playing. This isolates the amp from the noise on the A/C line and provides the other benefit of this amp: portability. That's right, you can take your high-end sound with you while you travel. Just connect to your favorite CD Walkman and phones and you will be immersed in high-fidelity music. (See the Acoustic Sounds "on-the-road" package for more information.)