Fangrui Product Details 1. Use M65831ap And Ne5532 2. The Electrolytic Capacitor Signal Main Circuit, The Capacitor Adopts Erkan Capacity 2x3300uf, And Adopts 5a And Above Rectifier To Strong And Continuous . 3. The Use Of High-precision Chip Resistors Ensures A Good Signal-to-noise Ratio Of The Whole Machine. 4. The Pcb Uses 1.6mm Thick Double-sided Sheets, 2.0a Copper Thickness, And Full Tin Spraying Process To Good Passing Performance Of Large And Small Currents. Top- Pcb Quality. 5. The Ok Input Operational Amplifier Uses Ne5532 For Amplification, The Output Uses Double-precision Ne5532, And The Karaoke Core Uses M65831, Which Has Good Analytical Power And Natural And Delicate Sound. There Is Also A Reverberation Delay Adjustment On The Board. Input Voltage: Ac12v-15v Dual Voltage Potentiometer Functions From Left To Right: Ok1, Ok2 Reverberation Depth Music Volume The Switch Is Delayed Adjustment Note: Different Batches May Have Differences In Product Appearance, Color, And Printed Characters, Which Not Affect The Use C