The 2A3 Triode

2A3. The 2A3 is one of the greatest tubes of all time, and is the very definition of hifi, being the power tube of the device that was first labeled with that title, RCA’s 1935 D-22 with push pull 2A3 power. The 2A3 dominated the high-end radio market of the 1930's, and was reportedly Paul Klipsch's favorite tube. E.H. Scott loved it enough to include 12 of them running in push-pull in his amazing 1935 Quaranta Amplifier. The 2A3 served an industrial role as well, and was common in US Military regulated power supplies during and after WW2. The 2A3 dates to 1932 or so, but was in production until the 1980's. There's a reason, it’s a beautiful sounding tube. Tube data for the 2A3 can be found here.

2A3. A roundup of 2A3 tubes. Starting with a Ken-Rad tube likely from the 1940’s, an early 2000’s Sovtek Reflektor 2A3 (which is sonically the best of the lot here in my experience), Sophia’s mesh plate globe, JJ’s massive 2A3-40 and a Belgian 6B4G tube, which is actually just a 2A3 with a different base.

2A3. Prized possessions, a pair of new in the box mono plate 2A3 from Triad. These are incredible tubes.