Western Electric ONE (1) 272A preamp triode tNOS AT1000 TESTED Vacuum Tubes mesh plate IOB Audio 1957

This listing is for one (1) 272A preamp triode vacuum tube in the ST (Coke bottle) tube shape. It has a black bakelite 4-pin base, mesh plate, and bottom D getter.

Your tube has been fully tested on a computer-regulated, USA-made Amplitrex AT1000 on Fixed Bias setting with like new, NOS results (tNOS). Here's what that means: to qualify for this listing, several stringent conditions must be met: The plate current must measure between 5 mA and 7.4 mA AND transconductance must measure between 560 uMhos and 840 uMhos, consistent with original 1957 RCA, Sylvania, GE, and/or Tung-Sol datasheet specifications for new tubes of this type. The tube must also show no shorts, show a gas current less than 0.62 mA, and a heater-to-cathode leakage of less than 10 microamps (10 uA). The tube might have mechanical wear or have the label rubbed off - these are very old! Used-testing tubes are available in a separate listing at a significant discount. Every tube you receive from Sound By Doc is guaranteed against failure for 60 days after purchase, an industry extreme!

These photos are not stock photos. You are looking at the actual tube you will receive. Serial Number WE-01-03.