Sylvania 12AV7 Vacuum Tube Black Plate NOS-Testing Sylvania NOS-Testing perforated plates

perforated plates

Three are GE and two are Sylvania

BECAUSE OF THE BIZARRE

new in box Amperex 3A2 tubes tested to spec on our Paul Hart-calibrated TV7/U

Sylvania 12AV7 Vacuum Tube Black Plate NOS-Testing Sylvania NOS-Testing perforated platesThis 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