public address system preamplifier Specs:mic strong intercalation,resistance/pressure input,with 12V out connector. 1, the rated output power: 40W2, 4-16 ohm3, frequency response: 40Hz-18KHz ± 0.5Db4, total harmonic distortion: ≤ 0.2% (at rated output power)5. size: 260X200X66 (mm)