The F388-2-Q is a powerful and durable headphone amplifier in 19 "format with two + two balanced stereo inputs on the back. It feature 4 identical amp section each with a volume and a balance control. The stereo signal from module 1 can be looped through to module 2 with a link switch. Internally, Pre-Gain can be set to -12 / -6 / 0 / +6 / +12 dB to adapt the amp to virtually every source - headphone combination. The amplifiers feature a very low output impedance in order to drive low-impedance headphones without any coloration. Due to the unusual high internal operating voltage also with high-impedance headphones a more than adequate sound level is maintained.