1. The board is a single-channel power amplifier board, which requires dual-channel 2. The circuit design uses A970/C2240 high-voltage audio pair tube dual differential circuit and A1145/C2705 for voltage amplification to the use of mid-power pair tube A1837/C4793, and the output stage uses A1943/C5200 high-power pair tube. 3.Wide power supply range, DC plus or 20V-90V can be, as long as enough power is supplied to reach 200, the sound quality is good, the driving force is strong, and the 15-inch speaker is pushed without pressure! 4. Power supply: dual voltage, DC plus or 20-90V (the upgraded version has optimized the circuit and parts, To directly apply high voltage, it is recommended to use 90V, do not challenge the voltage limit. ) 5. : undistorted power 200W, maximum power 300W. Colour:black Material:ABS Package Contents: 1 x HiFi 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.