Amperex 12AX7 ECC83 Vacuum Tube Valve Early 1950s Welded Plate Large D Slanted Getter

Amperex 12AX7 ECC83 Vacuum Tube Valve Early 1950s Welded Plate Large D Slanted GetterThis Dutch Amperex ECC83 12AX7 dual triode was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas and it measured 41 38 where minimum (65%) is 32 32 and 100% is 49 49. This tube is RCA branded; has solid, spot welded ribbed plates; copper support rods; a 509 date code; sutured tops and a large D getter angled at 45 degrees. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY

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

I have played it in my Bottlehead Crack headphone amplifier and it sounds outstanding

This new old stock-TESTING matched pair of Sylvania 6F6GT tubes was tested on our Maxi-Matcher 325 volts on the plates and a bias of -36 volts for shorts

It measured 54/66 where minimum (65%) is 50/50 and 100% is 77/77

Tube One drew 19

37 and 44 where minimum (65%) is 25

The dust jacket shows some wear

They measured 28

This lot of two Sylvania 35Z3 rectifier tubes tested 52 and 60 on our Paul Hart-calibrated TV7/U where minimum (65%) is 40 and 100% is 62

The tubes have black plates

a round mica spacers and gray plates

matching 9-39 date codes