Telefunken 12AX7 ECC83 Vacuum Tube Ribbed Plate For Your Univalve Or Bottlehead 12AU7 ECC82 new in box Philco 7A5

new in box Philco 7A5 tube tested to spec on our Paul Hart-calibrated TV7/U

(New EL84s typically test from the mid 20s to mid 60s with transconductance from 7420

Transconductance was 2180 for Tube One and 2150 for Tube Two where new/nominal is within one standard deviation of 1900

It measured 120 where minimum (65%) is 50 and 100% is 77

Telefunken 12AX7 ECC83 Vacuum Tube Ribbed Plate For Your Univalve Or Bottlehead 12AU7 ECC82 new in box Philco 7A5This Telefunken ribbed plate ECC83 12AX7 dual triode was tested on our Paul Hart calibrated TV7 U for shorts, gas, noise, transconductance and gain. There were no shorts, noise or gas. It measured 39 42 where minimum (65%) is 32 32 and 100% is 49 49. It has excellent flashing and a chunky O getter. Its base has the requisite Telefunken diamond embossed with a "24" code with a backwards "7" below it. I am playing it in my Pro Ject Tube Box S phono