6SJ7

Octal 8-pin metal shell sharp-cutoff pentode designed for low-noise high-gain audio voltage preamplification, instrument circuits, and RF/IF amplification stages. Equivalents: 6SJ7GT, 5693 (premium red-base), VT-116, CV1982. Real-Life Examples: Fender "Woodie" and early Tweed guitar amplifiers, Gibson BR-6 amplifiers, vintage laboratory VTVM input stages.