Matched Pair General Electric GE 12B4 12B4A Vacuum Tubes Valves 9ED4 T39 Enhanced Cooling: no

Enhanced Cooling: no

These tubes have narrow 19 MM plates

It is dead quiet when the preamp is muted and has excellent frequency response and dynamics even though it tests poorly

One is labeled "Philco

A seven out of ten

Matched Pair General Electric GE 12B4 12B4A Vacuum Tubes Valves 9ED4 T39 Enhanced Cooling: noThis 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"