RCA Cunningham 5Z3 Vacuum Tube Black Plate Rectifier Shoulder ST Shape 3CZ3A Octal I am playing them in

I am playing them in my ArtSound single-ended 805 monoblocks with Steely Dan’s seminal "Aja" album

new in box Zenith 2BU2 / 2AS2 / 2AS2A / 2AH2 tested to spec on our Paul Hart-calibrated TV7/U

As I test new-in-box 5963s

This black plate Delco 5Y3G rectifier tube was tested on our Paul Hart-calibrated TV7/U for shorts

I am playing it in Bottlehead Crack headphone amplifier as a 12AU7 substitute and it sounds excellent

RCA Cunningham 5Z3 Vacuum Tube Black Plate Rectifier Shoulder ST Shape 3CZ3A Octal I am playing them inThis RCA Cunningham 5Z3 rectifier tube was tested on our Paul Hart calibrated TV7 U for shorts, gas and emissions. It tested 68 in Section One and 58 in Section Two where minimum (65%) is 40 40 and 100% is 62 62. It has a tall, engraved stamped base; black plates, copious amounts of flashing and a nice, old fashioned shoulder bottle. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT. PLEASE ALSO SEE OUT ETSY SISTER SITE