Matched Pair Sylvania 6C4 Vacuum Tubes Black Plates Copper Support Rods Ken-Rad NOS-Testing Delco-BRANDED 6SK7 tested as good

Delco-BRANDED 6SK7 tested as good on our Paul Hart-calibrated TV7/U

new in box RCA 14Q7 tubes tested to spec in our Jackson 648 Mutual Conductance tester

with a very low noise floor and excellent soundstaging

These tubes have mica snubbers for increased stability and lowered microphonics

new in box Sylvania 12AV7 dual triode was tested on our Paul Hart-calibrated TV7/U for shorts

Matched Pair Sylvania 6C4 Vacuum Tubes Black Plates Copper Support Rods Ken-Rad NOS-Testing Delco-BRANDED 6SK7 tested as goodThis almost perfectly matched pair of Sylvania black plate 6C4 triodes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Tube One measured 60 while Tube Two measured 62 where minimum (65%) is 55 and 100% 85. They have top D getters; copper support rods and nice flashing. They sound great in my Alan Eaton single ended 45 amplifier (with an adapter, not included). WE HAVE SCORES OF THOUSANDS