1. supply: dual DC supply ± 58 --- ± 70V 2. The rated output : 500W (± 65V supply, 4 ohm load, distortion 10%) 3. Efficiency:more than the = 90% 4. : 90dB 5. The harmonic distortion:380W (± 65 4 ohm speaker, distortion Less than 0.1%) 280W (± 65 8 ohm speaker, distortion Less than 0.1%) 6. Frequency range: 20Hz-20KHz 7. Speaker: 4-8 ohm 8. Voltage Magnification: 36 9. Input sensitivity 1.5V () 10. Output short circuit protection: Yes 11. output DC bias protection speaker protection: Yes 12. Over-temperature protection: Yes, radiator FET temperature higher than 100 Celsius, turn off the output! Colour:Photo Color Material:ABS Size:98 x 43 x 30mm Package Contents: 1 * Digital amplifier board precautions: 1. Rated supply voltage is ±65V, ±58---±70V range, do not over 70V! positive and negative do not pick wrong 2. Recommended supply ±65V 3. Recommended 4-8Ω / 10-18inch speaker 4. Carefully check before , the wiring is . Only the above package content, other products are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.