Matched Pair Sylvania 6K6 6K6GT Vacuum Tubes Valves Angel Records 35657 70/50 and 72/60 where minimum

70/50 and 72/60 where minimum (65%) is 50/40 and 100% is 77/62

I am writing during the first few pianissimo minutes and the surface noise is distracting

The two on the left were made by Mullard

new in box milspec National Union JAN-CNU 2X2A VT-119 879 tube tested to spec on our Paul Hart-calibrated TV7/U

Matched Pair Sylvania 6K6 6K6GT Vacuum Tubes Valves Angel Records 35657 70/50 and 72/60 where minimumThis matched pair of Sylvania MANUFACTURED, Philco LABELED 6K6GT tubes was tested on our Maxi Matcher 400 volts on the plates and a bias of 36 volts for shorts, gas and transconductance. There were no shorts or gas. Tube One drew 18. 4 milliamps' plate current and measured 1460 micromhos. Tube Two measured 19. 5 1710. New nominal is within one standard deviation of 1900. These tubes have copper support rods; rectangular mica spacers; anode radiators