Matched Pair Sylvania 6AU6 6AU6A Vacuum Tubes Valves NOS-Testing RCA Vinyl Stereo new in box GE 1821A

new in box GE 1821A / Z-1879A is still sealed in its plastic baggie

perfectly-matched pair of GE 6SJ7s was tested on our Paul Hart-calibrated TV7/U for shorts

on our Paul Hart-calibrated TV7/U where minimum (65%) is 31 and 100% is 48

new in box Sylvania 14C5 tubes tested to spec on our Paul Hart-calibrated TV7/U

phi-shaped mica spacers

Matched Pair Sylvania 6AU6 6AU6A Vacuum Tubes Valves NOS-Testing RCA Vinyl Stereo new in box GE 1821AThis new old stock testing matched pair of Sylvania 6AU6A tubes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 72 for Tube One and 74 for Tube Two where minimum (65%) is 58. I am playing them in my Musical Paradise MP 3 single ended integrated amplifier (with adapters, not included) with Aimee Mann's seminal "Magnolia" album and they sound terrific. These tubes