Matched Pair RCA 12SN7 12SN7GTA Vacuum Tubes Black Plate NOS NIB Tung-Sol 6K6

Matched Pair RCA 12SN7 12SN7GTA Vacuum Tubes Black Plate NOS NIB Tung-Sol 6K6This 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

SOMETIMES TUBES THAT TEST WELL HAVE PROBLEMS AND SOUND AWFUL

It rattles but is otherwise OK

Transconductance readings are 25

engraved bases and narrow rectangular mica spacers

though they are labeled differently

STOLEN AND LOST

These four metal base National Union 6Q7GT tubes tested to spec on our Paul Hart-calibrated TV7/U

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

These lot of six new old stock

" "My Darling's Ring