Sylvania 12AV7 Vacuum Tube NOS NIB Black Plate For Your Bottlehead Juan Rosenkavalier This hardcover book is in

This hardcover book is in very good condition

PLEASE BE PATIENT FOR THE FIRST DAY OR TWO IF THE PACKAGE IS STILL MARKED AS "PRE-TRANSIT

This new old stock-testing matched pair of milspec RCA 1619 tubes were tested on our Paul Hart-calibrated TV7/U for shorts

straight-bottle bottle variety

(New US-made 7408s typically test with plate current from the mid-teens to mid-30s with transconductance from 2300 micromhos or so

Sylvania 12AV7 Vacuum Tube NOS NIB Black Plate For Your Bottlehead Juan Rosenkavalier This hardcover book is inThis new old stock, new in box Sylvania 12AV7 dual triode was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 41 42 where minimum (65%) is 21. This tube has black plates; an O getter; terrific flashing and GJ MVWV date codes. I am playing it in Bottlehead Crack headphone amplifier as a 12AU7 substitute and it sounds fine. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES.