Portable headphone amplifier. Featuring a vacuum tube on the primary stage amplifier and the Fostex custom made capacitor delivering richly textured sound reproduction from any type of audio source, never achieved by any other vacuum tube amplifier. Headphone amplifier adopting a vacuum tube (6N16B-Q) on the primary stage and OPAMP on the secondary stage (no DAC built in). Easy-to-carry light weight and robust aluminum chassis. 2 x 3.5 mm stereo mini jack inputs on Front (priority) and Rear to fit to any type of player unit. The coupling capacitors consist of Fostex's original large film capacitor and electrolytic capacitor, which were designed based on the Fostex's hi-fi speaker engineering. Comes with 100 mm high quality stereo mini cable as standard. Hi/Lo Gain switch to drive various type of headphones. Approx. 10 hours continuous operation from the rechargeable Lithium Ion battery. Max SPL: 200 mW / 32 Ohm. Frequency response: 20 Hz - 100 kHz +/- 2 dB. AC adapter included.