Matched Pair General Electric GE 12B4 12B4A Vacuum Tubes Black Plates Copper Support Rods NOS-Testing TA2 where minimum (65%) is 38/38

where minimum (65%) is 38/38

Tube Three measured 58

They are exactly-the same on the inside

Tube One drew 21

Matched Pair General Electric GE 12B4 12B4A Vacuum Tubes Black Plates Copper Support Rods NOS-Testing TA2 where minimum (65%) is 38/38This new old stock testing matched pair of GE 12B4A tubes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Tube One measured 44 while Tube Two measured 48 where minimum (65%) is 32 and 100% is 49. Wish I could tell you how they sound, but I don't have any equipment that uses these. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT. PLEASE ALSO SEE OUT ETSY