Matched Pair RCA 12SN7 12SN7GTB Vacuum Tubes Stereo LP-1973 This new old stock-testing RCA

This new old stock-testing RCA black plate 12AU7A dual triode was tested on our Paul Hart-calibrated TV7/U for shorts

This is an early-production 12AU7 -- not a 12AU7A like most 12AU7s we see these days

double-side getters and and absolutely no flashing -- somewhat-disconcerting

I’ve never met a von Karajan completist as Karajan was just too prolific for any normal human to be a von Karajan completist

It measured 56/49 where minimum (65%) is 40/40 and 100% is 62/62

Matched Pair RCA 12SN7 12SN7GTB Vacuum Tubes Stereo LP-1973 This new old stock-testing RCAThis matched pair of RCA 12SN7GTB dual triodes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas and transconductance measured as follows: Tube One: 63 64 Tube Two: 66 60 Bogey: Minimum (65%) is 50 50; 100% is 77 77 Physical Characteristics: Bases: tall Bottles: medium height Date Codes: 3 48 and 4 35 EIA Factory Codes: RCA logo; 274 Getters: bottom, D Flashing Quality: N A Mica Spacers,