RCA 12AU7 12AU7A ECC82 Vacuum Tube NOS-Testing Black Plate Slant D Getter For Your Univalve Or Bottlehead VR150 T31 It has very light surface

It has very light surface noise

I am playing them as I write in my Radio Craftsmen RC-2 monoblocks with RCA Living Stereo's CD of Bartok's "Concerto For Orchestra

This tube has 21 MM black plates

There were no shorts or gas and it measured / where minimum (65%) is 40/40 and 100% is 62/62

and as I test new-in-box 5963s

RCA 12AU7 12AU7A ECC82 Vacuum Tube NOS-Testing Black Plate Slant D Getter For Your Univalve Or Bottlehead VR150 T31 It has very light surfaceThis new old stock testing RCA black plate 12AU7A dual triode was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. This tube has 17MM black plates; a slant D getter; steel support rods and nice flashing. It measured 70 82 where minimum (65%) is 56 56. I have played it in my Bottlehead Crack headphone amplifier and it sounds terrific. It is dead quiet when the volume is muted and has excellent