Matched Pair RCA 5963 12AU7 12AU7A Vacuum Tubes Black Plate Industrial-Grade 2nd Quadrimester LP Its diodes measured 54 and

Its diodes measured 54 and 42

82 and 85 where minimum (65%) is 58 and 100% is 89

Tube One (12B4

This Sylvania 5933 / 807W / FU7 output tube was tested on our Maxi-Matcher 2 for shorts

These three US-made 12AV5 output tubes were tested on our Paul Hart-calibrated TV7/U for shorts

Matched Pair RCA 5963 12AU7 12AU7A Vacuum Tubes Black Plate Industrial-Grade 2nd Quadrimester LP Its diodes measured 54 andThis matched pair of RCA black plate 5963 dual triodes was tested on our Paul Hart calibrated TV7 U and our Maxi Preamp II for shorts, gas, noise, transconductance and gain. There were no shorts, noise or gas and they tested as follows: Tube One: Noise: 85. 2 dB 85. 6 dB ( 92 dB is the Maxi Matcher's noise floor) Transconductance (Maxi Matcher): 1789 1690 Transconductance (TV7 U): 55 55 where minimum (65%) is 50 50 and 100% is 77 77. Gain (Mu (): 17.