NUX PHT-2 Headphones Amplifier Versatile Portable Headphone Preamp Features: PHT-2 is a versatile portable headphone preamp. It has two channels that can handle Stereo and Mono signals. Each channel has independent level control and two input jacks. You can use 4 headphones at the same time. With the LINK function, you can link many PHT-2s together. Two-channel stereo headphone preamp. Balanced and Unbalanced Outputs AUX IN, RCA In Master Volume Control LED Level Indicator Link jacks. 9V DC Adaptor(negative tip) Specifications: Input impedence:10KΩ Output impedence:10KΩ Dynamic range:96dBu Noise-signal ratio:-94dBu Frequence Response:20Hz-20kHz -1dBu-0.5dBu THD+N:0.027%(0dBu) Earphone output power:30mW\/channel Signal indicating lamp:-10dBu Working voltage:9V Working current:240mA Power:DC 9V Size:121*84*55mm Weight:350g Manual: Click here Package Included: 1x NUX PHT-2 Headphones Amplifier 1x Manual