Description: A908 Compact PreAmp 4-channel Stereo Headphone/Speaker Amplifier, one in four out, with independent channel to control volume adjustment Made of all metal, durable The panel has a 6.5mm headphone jack and a 3.5mm to 6.5mm adapter to meet the output of the speakers and headphones. Max. Signal input voltage: 450mV SNR: 120dB(A) Output power: 140mW Distortion: ?0.02% Channel separation: ?120dB Frequency response: 20Hz-20kHz ( ±0.05dB) Output noise: