Sylvania 12AV7 Vacuum Tube Valve Black Plate NOS-Testing 17BZ3 T18 a round mica spacers and

a round mica spacers and gray plates

I am playing them in one of my Radio Craftsmen SC-2 monoblocks as I write

It comes with a box

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

This Moss Music Group DBX pressing has no surface noise but a very few pops and ticks

Sylvania 12AV7 Vacuum Tube Valve Black Plate NOS-Testing 17BZ3 T18 a round mica spacers andThis 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