RCA Clear Top 12AU7 ECC82 Vacuum Tube For Your Bottlehead Or Univalve NOS-Testing Westinghouse NIB It measured 75 where minimum

It measured 75 where minimum (65%) is 50 and 100% is 77

black and silver bottles and 6-52 188-5 and 3-09 188-5 provenance/date codes

These four new old stock

It is dead quiet when the preamp is muted and has excellent frequency response and dynamics

I will update this listing

RCA Clear Top 12AU7 ECC82 Vacuum Tube For Your Bottlehead Or Univalve NOS-Testing Westinghouse NIB It measured 75 where minimumThis new old stock testing RCA clear top 12AU7 dual triode was tested on our Maxi Preamp II for shorts, gas, noise and gain. There were no shorts, noise or gas. Measurements are as follows: Noise dynamic range: 84. 6 dB 84. 9 dB; Transconductance: 1264 1360 and Gain (Mu): 16. 1 17. 2 New 12AU7s typically test within a standard deviation of 17 17 for gain. The noise floor on this tester is 92dB 92dB. There is no transconductance reference reading and