1. Power supply: dual DC power supply ± 58 --- ± 70V 2. The rated output power: 500W (± 65V power supply, 4 ohm load, distortion 10%) 3. Efficiency:more than the = 90% 4. SNR: 90dB 5. The total harmonic distortion:380W (± 65 power 4 ohm speaker, distortion Less than 0.1%) 280W (± 65 power 8 ohm speaker, distortion Less than 0.1%) Frequency range: 20Hz-20KHz Speaker: 4-8 ohm Voltage Magnification: 36 times Input sensitivity 1.5V (RMS) Output short circuit protection: Yes That output DC bias protection speaker protection: Yes 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: 3 x Digital power amplifier board Use precautions: 1. Rated supply voltage is ±65V, ±58---±70V range, do not over 70V! positive and negative do not pick wrong 2. Recommended power supply ±65V 3. Recommended 4-8Ω / 10-18inch speaker 4. Carefully check before electricity, the wiring is correct. 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.