This is the bare PCB of a pure class A MOSFET amplifier, output power 20Wrms at 8 ohms loading. The circuit use a tube ( E88CC or 6922 ) as the input stage. The tube worked as a long-tail pair loaded by a current mirror. The output is a MOSFET in SE class A mode which is loaded by a current source composed of another power MOSFET. This architecture was based on a hybrid headphone amplifier designed by Borbely. It was eventually adapted as a power amplifier. Working at +/-36V, the amplifier can give 20Wrms non-clipping output power in class A. This is a single channel amplifier PCB. Two PCBs are needed to form a stereo amplifier. PCB dimension : 210mm x 65mm. PCB thickness : 1.6mm, 2 oz ( 75um thickness copper) deposition which is FOUR times normal process of copper thickness. Gold plated surface. We provide adjustment guide/schematic and part list to customers by EMAIL. We do air shipping worldwide at US$6.00. We welcome combine shipping. Track Page Views With Auctiva's FREE Counter Powered by SoldEazy