... .8W (THD<=10%Distortion<0.5% (1KHz, 0.5W)S/N ratio>80dB (A-Weight)Frequency response90Hz-20kHzPower supply4 AA , USB ... power , AC adapter DC5VDimensions207mm(L) , 87mm(W), 86mm(D)Weight800g3 ways of ... power supply4 AA Batteries, USB, AC power adapterBest sound quality digital speakerElectronic volume control, no adjust ...