Matched Pair General Electric GE 12B4 12B4A Vacuum Tubes Valves 9ED4 T39 A 7 out of 10

A 7 out of 10

Enhanced Cooling: no

Transconductance measured 2850 micromhos for Tube One with a current draw of 21

Please be sure your device has enough current to run them

Matched Pair General Electric GE 12B4 12B4A Vacuum Tubes Valves 9ED4 T39 A 7 out of 10This 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 33 while Tube Two measured 34 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 SISTER SITE "LOWTECHTWOO"