Features: Overall architecture: NE5534 front-end amplifierandOP07 DCservoandC1237 speaker protectionandTDA7293 back-end amplifier, reasonable architecture, excellent sound quality, stable and reliable operation. The maximumpower depends on the power supply voltage and horn impedances, THD=10 percent , RL=82 VS=40V If it is a 42 load, please do not exceed the double AC20V transformervoltage to avoid unnecessary losses Please pay attention to monitoring the temperature of the heat sink during use. If necessary, it is recommended to use a fan to assist in heat dissipation Pre amplifier 5534 may have brands randomly shipped with the same sound quality. If there are special requirements, please raise them in advance to avoid disputes Specifications: Overall architecture: NE5534 front-end amplifierandOP07 DCservoandC1237 Speaker ProtectionsandTDA7293 back-end Amplifier Power supply voltage: AC12-28Vx2 (dualAC) Power supply: recommended above 200W Output power: 100Wx2 Output impedances: 4-16ohms Channel: 2-channel stereo Circuit architecture: TDA7293andOP07andNE5534 Feature: Front stage stabilizedDC servo delay protections Protections feature: overheatDC short circuit protections Size: approx 149.6x135x52mm or 5.89x5.31x2.05in Note: Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! Please allow 1-2cm measuring deviationdue to manual measurement. Package includes: 1PC Stereo HighPower 2.0 Power Amplifier Board Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.