The 6BD11 is an amplification beam power pentode vacuum tube typically used in audiocassette recorders and amplifiers. It typically consists of a cathode, an anode, a grid, a control grid, a plate, and a beam plate. The cathode is the primary source of electrons, while the anode and grid create the actual field in which the electrons flow and can be controlled by adjusting the control grid. The plate and beam plate also work together to further regulate the current. When voltage is applied to the cathode, electrons are released, creating a current in the tube and producing a signal.