DigiZoid ZAX Headphone Amplifier and Stereo PreAmp Combination Unit Class leading output power delivering the muscle needed for energy demanding headphones, previously available only in non-mobile audiophile systems. Unique configuration offering high performance headphone output in combination with drive circuits enabling buffered interconnection to stationary audio systems or to power speakers. Excellent full spectrum sound reproduction including superb low frequency response providing powerful bass and depth. Economical and convenient operation running on low cost AA batteries or an external AC/DC power source. Typical battery life in excess of 250 hours (single headphone). Best value on the market for handheld amplifiers delivering these features and performance.