The 6GB5 (European equivalent EL500 / EL504) is a heavy-duty beam power pentode vacuum tube originally engineered for television horizontal deflection output circuits. Known for its high peak current capabilities and high plate dissipation, it is also popular among radio amateurs and audio builders for constructing high-power linear amplifiers and single-ended audio output stages. It features a top plate cap for high-voltage isolation and operates on a 6.3V heater with a 9-pin base. Available NOS and tested used.