Matched Pair Sylvania EL34 6CA7 Fat Boy Output Tubes Valves NOS-Testing

Matched Pair Sylvania EL34 6CA7 Fat Boy Output Tubes Valves NOS-TestingThis new old stock testing matched pair of 1960s vintage Sylvania Fat Boy EL34 6CA7 tubes was tested on our Maxi Matcher 2 tube tester with 400 volts on the plates and a bias of 36 volts on the grids for shorts, gas and transconductance. There were no shorts or gas. Tube One drew 39. 2 milliamps' plate current while Tube Two drew 40. 2. Transconductance measured 5340 and 5260 micromhos, respectively where new nominal is within one standard deviation

I just cleaned both LPs in this album on my VPI 16

6 milliamps' plate current and measured 1830 micromhos

This pressing has light surface noise audible only in quiet passages

It measured 56/52 where minimum (65%) is 40/40 and 100% is 62/62

This lot of four US-made black glass as well as gray glass number / type 57 tubes was tested on our Paul Hart-calibrated TV7/U for shorts

new in box RCA 6BQ7 6BQ7A tube tested to spec on our Hickok 800

46 and 50 where minimum (65%) is 30 and 100% is 47

This new old stock-testing matched pair of GE 12B4A tubes was tested on our Paul Hart-calibrated TV7/U for shorts

new in box RCA 6KD6 tube -- and two just like it -- tested to spec on our Paul Hart-calibrated TV7/U

4 dB / -85

I am playing them with adapters (not included) in my Radio Craftsmen RC-2 monoblocks and they sound great

These 11 RCA gray glass 6D6 tubes were tested on our Paul Hart-calibrated TV7/U for shorts