Matched Pair Sylvania 6BL7 6BL7GTA Vacuum Tubes Triple 3 Mica NOS NIB Music Of The gray ladder plates

gray ladder plates

I am playing it in my Pro-Ject Tube Box S phono preamplifier with an Ortofon X5-MC high output moving coil cartridge as I write and it absolutely silent

new in box GE 5 Star 5663 premium tube tested to spec on our Paul Hart-calibrated TV7/U

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

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

Matched Pair Sylvania 6BL7 6BL7GTA Vacuum Tubes Triple 3 Mica NOS NIB Music Of The gray ladder platesThis 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