SIEMENS EF86 TRUE NOS Rare 8Yn Production Power Tube AT1000 TESTS NOS 6CF8 6267
RARE: 8Yn Production - Diamond Mark on Bottom. All tubes are tested with the Audiophile in mind for SHORTS, GAS, MUTUAL CONDUCTANCE and NOISE (large tube lots are not tested for noise). AT1000 TESTs as NOS.