1. The power supply should be 24V and the current should be above 3A. 2. It is best to use a speaker with an impedance of 4-8 ohms and higher sensitivity. 3. For some sound sources with relatively low signal levels, a preamplifier should be added to achieve the best effect. 4. Be careful not to connect the positive and negative poles in reverse, otherwise the circuit board will be burned. Connect the wires and confirm that there is no problem before turning on the power. Amplifier chip: TPA3116 Power supply voltage: 11-26VDC DC input with extreme reverse protection (recommended DC 24V current 3A and above switching power supply) Output power: stereo 50W+50W, PBTL mono 100w Load impedance: 4-8 ohms (speaker speaker impedance) Audio input: 2.54mm 3 pin header Due to different batches, there may be differences in product appearance and printed text, which will not affect use Colour:As Shown Material:PCB+Plastic+Metal Package Contents: 1 x Digital workplace 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.