1. The Power Amplifier Board Has A Thicker Radiator Based On The Old Model. Adopting Circuit Design, High Power, Good Sound Quality And Low Distortion! 2. Strictly Tested Various Parameters Of The Power Amplifier Board. The Two Channels Only Need To Be Connected According To The Wiring Diagram. 3. The Motherboard Comes With Its Own Filter Rectifier And Heat Sink. You Only Need To Connect The Power Supply, Transformer And Preamplifier! 4. Stereo Version 5. Mono Wiring: Just Connect The Included Red Plug-In To The K1 And K2 Boards To Achieve Mono Wiring. Working Voltage: Dual AC 24-45V Toroidal Transformer Power Amplifier Chip: Sanken1494/3858 Channel Type: Stereo Two-Channel, Mono Mono Output: 800W/4 Ohm Load Dual Channel Output: 400W+400W Impedance: 4 Ω / 8 Ω Note: Different Batches May Have Differences In Product Appearance, Color, And Printed Characters, Which Will Not Affect The Use Colour:As Shown Material:PCB+metal Package Contents: 1 x Power Amplifier Board Module 1 Set x Wires 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.