General Electric GE 6201 12AT7 ECC81 Vacuum Tube Valve Industrial Variety Triple 3 Mica NOS NIB For Your Univalve Perfectly-Balanced June 06 2023 I am playing it in

I am playing it in my Pro-Ject Tube Box S phono pre-preamplifier (tube on right) with John Mayall’s seminal "The Blues Alone" album

These tubes have copper support rods

I have no means to test this device

Transconductance measured 35

sutured tops

General Electric GE 6201 12AT7 ECC81 Vacuum Tube Valve Industrial Variety Triple 3 Mica NOS NIB For Your Univalve Perfectly-Balanced June 06 2023 I am playing it inThis new old stock, new in box, industrial grade GE triple mica 6201 (12AT7 ECC81) dual triode was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. It measured an absolutely, incredibly super rare, perfectly balanced 70 70 where minimum (65%) is 50 50 and 100% is 77 77. This happens perhaps once maybe twice per decade! This variety has copper support rods; gray plates; two additional, vertical