12B4A

Miniature 9-pin low-mu power triode designed for high-efficiency operation as a vertical deflection output amplifier in televisions, or as a highly linear, low-impedance voltage regulator and audio driver stage. Equivalents: 12B4. Real-Life Examples: Vintage RCA television vertical scan chassis, high-end custom OTL (Output Transformerless) headphone amplifiers, vintage radio power supply sub-regulators.