Headphone Amplifier Circuit simply have a design or even the first single MOSFET as the design begins after two MOSFETs used and 6n6p ecc99 lamp Adding the lamp operating voltage 70 … 80V inter-addition for the MOSFETs 18 …... Electronics Projects, Class A Tube Headphone Amplifier Circuit Mosfet Hybrid "audio amplifier circuits, transistor amplifier, " Date 2019/08/03