1. The power supply interface is embedded in the reverse protection unit, reverse connection does not burn 2. Output power depends on the power supply voltage and speaker impedance, high-power occasions recommended voltage 24v, current 5A, try to use 4 ohm speakers, conducive to high-power 3. The speakers must be boxed to use, recommended the use of finished boxes, homemade more complex and difficult to have good results, each channel, please strictly differentiate between positive and negative, connecting the reverse seriously reduce the sound efficiency 4. Speaker output for the BTL structure, it is strictly prohibited to use the common ground, otherwise the sound is not normal, may burn the amplifier 5. Dual-channel support 4 50w and 8 30w speakers, support 2 100w speakers Chip Type: TPA3116D2 x 2 Input Voltage: DC 8-24V Output Power: 50W x 2+100W (Left/Right Channel + Channel) Sound Channel: Dual Channel + Subwoofer Number of Channels: 2.1 Channels Output Impedance: 4-8 Frequency Response: 20Hz-20KHz Features: Power On Delay Anti-Shock Volume Adjustment: Knob Tuning clockwise volume + counterclockwise volume - Bottom noise judgment method: Input short-circuit, connected to the speaker to try to hear, normal should only be very weak noise (general distance from the speaker 50cm or so is not obvious) too large is not normal, if connected to the computer or cell phone noise increase indicates that the noise comes from the signal source! Color: As Shown Material: PCB Package Contents: 1 x TPA3116 digital power amplifier board 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.