This is the PCB of a stereo power amplifier using NS's renowned LM3886 power amplifier chip. The circuit uses a 6N11 ( or 6922 or 6DJ8) as the input stage to enhance the musicality of the amplifier. Either the circuit can be fed by 35Vx2ac which can be supplied to both the LM3886 power amplifier and the 6N11 tube, or for higher performance a separate 65Vac be fed to the tube. A 8Vx2 is also needed for the tube filament. Speaker protection circuitry is also included using the very robust uPC1237. Product Specifications: Output Power: 68W x2 ?4?) Operating voltage : 28V-0-28V, 65V, 8V Operating type : Class AB type amplifier. Input Impedance: 47K Output Impedance: 4-8? Features : PCB size: 165 mm x 80 mm; PCB thickness 1.6mm; 2 ounce thick copper plating. This is a stereo amplifier. We provide schematic and part list for this sale. The assembled amplifier picture is attached for reference. We do air shipping worldwide at US$6.00. We welcome combine shipping. On Apr-11-11 at 12:15:59 PDT, seller added the following information: SquareTrade AP6.0 SquareTrade squaretrade warranty v2.0 Powered by SoldEazy