Matched Pair Sylvania 6BL7 6BL7GTA Vacuum Tubes Triple 3 Mica NOS NIB Music Of The I have played it in

I have played it in my Bottlehead Crack headphone amp and it sounds great

These tubes have lyre-shaped getters

Tube One measured 60/56 while Tube Two measured 61/58 where minimum (65%) is 50/50 and 100% is 77/77

They have 3-13 188-5 and 3-26 188-5 date/provenance codes

This double CD plays fine

Matched Pair Sylvania 6BL7 6BL7GTA Vacuum Tubes Triple 3 Mica NOS NIB Music Of The I have played it inThis new old stock, new in box, almost perfectly matched pair of Sylvania MANUFACTURED 6BL7GTA dual triodes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 46 48 for Tube One and 48 47 for Tube Two (Sylvania MANUFACTURED, RCA LABELED). (Minimum (65%) is 25.) They have top D getters; anode radiators for cooler operation and longer tube life; copper support rods; a