Sylvania 12AV7 Vacuum Tube Valve Black Plate NOS-Testing 17BZ3 T18 It comes with a box

It comes with a box

new in box RCA 36MC6 / 36MC6A tubes tested to spec on our Paul Hart-calibrated TV7/U

This RCA Radiotron number / type 80 rectifier tube was tested on our Paul Hart-calibrated TV7/U

We also have Soviet-era tubes to go with it

Sylvania 12AV7 Vacuum Tube Valve Black Plate NOS-Testing 17BZ3 T18 It comes with a boxThis new old stock testing Sylvania 12AV7 dual triode was tested on our Jackson for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 116% 104% where minimum (65%) is 70% 70%. This tube has black plates; a horseshoe getter and terrific flashing. I am playing it in Bottlehead Crack headphone amplifier as a 12AU7 substitute and it sounds excellent. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE