3 US-Made 12SF7 Vacuum Tubes Valves Lot Of Three Trio

3 US-Made 12SF7 Vacuum Tubes Valves Lot Of Three TrioThese new old stock testing US made 12SF7 tubes were tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas.. They measured 71, 74 and 76, respectively, where minimum (65%) is 46 and 100% is 71. IN 2021 WE PURCHASED 150,000 VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT. PLEASE ALSO SEE OUT ETSY SISTER SITE "LOWTECHTWOO" AND OR CALL OR TEXT US AT 202 372 6931 IF YOU DO NOT SEE WHAT YOU NEED OR HAVE

These three RCA plate number 78 tubes were tested on our Paul Hart-calibrated TV7/U for shorts

These three GE 6M11 tubes are new old stock

new in box Amperex 5915 tubes tested to spec in our Paul Hart-calibrated TV7/U

They are microphonic and are fine in the preamp stage of my MP-301 and other gentle environments

new in box GE 12ED5 tubes tested to spec on our Paul Hart-calibrated TV7/U

This pressing has light surface noise audible in quiet passages and barely audible in voice-level passages

These tubes have gray plates and nice flashing

It measured an absolutely

They have great bass and sparkling highs and Mann's voice is warm and clear as a bell

They have HG YCN and EJ date codes

This new old stock-testing almost-perfectly-matched pair of Sovtek 6BQ5 / EL84 / 6P14 / 6P14P output tubes was tested on our Maxi-Matcher 2 -- with 325 volts on the plates and a bias of -14 volts -- for shorts

It measured 42/44 where minimum (65%) is 33/33 and 100% is 51/51