Soviet double triode tube 6N8S (6H8C rus.) manufacturer FOTON. Designed for low-frequency voltage amplification in preamp stages and phase inverters. Features octal base, separate cathodes, 6.3V/600mA heater, gain (µ) ~20.5. Equivalent to tubes: 6SN7, 1578, 6SN7GT, 6SN7GTA. NOS
6N8S Datasheet.pdf