This is a bare PCB of tube buffered LM4780 stereo power amplifier. With two LM4780 on one board, each LM4780 power amplifier IC is in parallel configuration. Similar design has been used in famous branded products like Rowland Research, who used three LM3886 ( essentially LM4780 is two LM3886 in one package) in parallel to give effortless power delivering. The power amplifier is preceded by a tube buffer to maximize musicality. The tube buffer circuitry is based on the well-proven, very good sounding X-10 design. The board also includes speaker protection circuit for each channel. This is a stereo design. Power supply : 28Vx2 AC, 6A and 12Vx1 AC, 1A Board Dimension : 254mm x 140mm. Thickness : 2mm. The PCB uses 70um thick copper ( 4 times normal thickness) and is gold plated. We provide schematic and part list to buyers by email , attaching to the shipment notice on the date of parcel posting. We do air shipping worldwide at US$6.00. We welcome combine shipping. Powered by SoldEazy