The F388-2-D is a 19 Inch, durable, powerful, headphone amplifier with balanced stereo inputs on the back. It features two stereo amplifiers, each equipped with volume and balance control. The internal gain can be adjusted to -12 / -6 / 0 / +6 / +12 dBr. The amplifier has low-impedance in the output to drive low-impedance headphones without coloration and features a high internal operating voltage to be sure high-impedance headphones gert what they need as well.