Fine audio 9 pin double triode tubes manufactured in the United States by Raytheon. Similar to 12AU7, these excellent quality miniature glass preamp tubes come with long gray ribbed plastes and top halo getters. They are printed in yellow RAYTHEON MADE IN U.S.A. 5963, and coded 280 with 1960's production codes. They are also glass-etched BSBA U.S.A.
Data sheet
Fine audio 9 pin double triode tubes manufactured in the United States by Raytheon. Similar to 12AU7, these excellent quality miniature glass preamp tubes come with long gray ribbed plastes and top halo getters. They are printed in yellow RAYTHEON MADE IN U.S.A. 5963, and coded 280 with 1960's production codes. They are also glass-etched BSBA U.S.A.