1. Power supply voltage: dual DC power supply 45--70V (recommended +-65V power supply can be) 2. Rated output power: 500W (65V supply 4 ohm load, distortion degree 1%) 3. Efficiency: equal 90% 4. Signal to noise ratio: 90dB 5. Total harmonic distortion: 380W (70 supply 4 ohm speaker, distortion Less than 0.1%). 280W (70 powered 8 ohm speaker, distortion Less than 0.1%) 6. Frequency response range: 20Hz-20KHz 7.Horn: 4-8ohm 8. Voltage amplification: 50 times 9. Input sensitivity 1V (RMS) 10. Output DC bias protection . horn protection: Yes 11. Amplifier board size: LxWxH=105x43x28mm 12. Weight: 100g Colour:Photo Color Material:plastic Package Contents: 1 x Digital Power Amplifier Board Note: The factory batches are different, and some parts may be different, which has no effect on the product Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.