Matched Pair RCA 12SN7 12SN7GTA Vacuum Tubes Black Plate NOS NIB Tung-Sol 6K6 gas and transconductance with 400

gas and transconductance with 400 volts on the plates and a bias of -48 volts

They measured 82/76 for Tube One and 85/74 for Tube Two

They sound spacious with excellent dynamic range and frequency response on these challenging pieces -- and are dead quiet when the CD player is muted

It rattles but is otherwise OK

Matched Pair RCA 12SN7 12SN7GTA Vacuum Tubes Black Plate NOS NIB Tung-Sol 6K6 gas and transconductance with 400This new old stock, new in box matched pair of RCA 12SN7GTA dual triodes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Tube One measured 76 76 and Tube Two measured 79 77 where minimum (65%) is 50 50. They have short bases; tall bottles; D getters; steel support rods; DB and CV batch codes, respectively, and their top mica spacers have two X patterns incised into them. I am playing them