Feature:1. 500W power amplifier board, the input signal sensitivity is 1.5V rms, if the input signal voltage can\u0027t reach this value, recommended to add a preamplifier.2. Premium amplifier board can help you amplify the weak signal from the audio source or pre-amplifier without changing the sound quality.3. Support output short circuit protecting, output direct current bias protecting(speaker protecting) and over temperature protecting, safer to use.4. Made of high-quality material, it has nice durability, with cooling fan and aluminum alloy heat sink, nice heat dissipation.5. The rated power supplys voltage is dual power supplys ±65V, and the voltage can work normally at ±58--±70V (over 70V, it will burn).Specification:Features:500W power amplifier board, the input signal sensitivity is 1.5V rms, if the input signal voltage can't reach this value, recommended to add a preamplifier.Premium amplifier board can help you amplify the weak signal from the audio source or pre-amplifier without changing the sound quality.Support output short circuit protecting, output direct current bias protecting(speaker protecting) and over temperature protecting, safer to use.Made of high-quality material, it has nice durability, with cooling fan and aluminum alloy heat sink, nice heat dissipation.The rated power supplys voltage is power supplys ±65V, and the voltage can work normally at ±58--±70V (over 70V, it will burn).Specifications:Material: PCB + Aluminum AlloyPower Supplys Voltage: Direct Current Power Supplys ±58---±70VRated Output Power: 500W (±65V power supplys 4 ohm load, distortion 10%)Efficiency: ≥90%Signal to Noise Ratio: 90dBFrequency Response Ranges: 20Hz-20KHzSpeaker: 4-8ΩVoltage Magnification: 36 timesInput Sensitivity: 1.5V (RMS)Output Short Circuit Protecting: YesOutput Direct Current Bias Protecting, Namely Speaker Protecting: YesOver-Temperature Protecting: Yes, the radiator field effect tube temperature is higher than 100 °C, turn off the output!Item Size: 98 * 43 * 30mm/ 3.9 * 1.7 * 1.2inItem Weight: 95g/ 3.4ozPackage Size: 100 * 50 * 30mm/ 3.9 * 2.0 * 1.2inPackage Weight: 100g/ 3.5ozPacking List:1 * Power Amplifier BoardPackage List:1 * Power Amplifier Board