Fine double triode audio tubes by various manufacturers. These 9 pin miniature glass amplifier tubes come with top getters, short gray plates, and thick mica internal supports minimising microphony. They have various manufacturers markings.
Data sheet
Fine double triode audio tubes by various manufacturers. These 9 pin miniature glass amplifier tubes come with top getters, short gray plates, and thick mica internal supports minimising microphony. They have various manufacturers markings.