1. The 6AU8A is a small-signal, dual triode vacuum tube with a 9-pin miniature base.
2. It was used in various consumer and industrial applications, including as a part of radio and television equipment.
3. It is highly resistant to microphonic feedback and produced a clean loud sound with minimal background noise.
4. The 6AU8A was one of the more popular preamplifier tubes used in the 1950s and 1960s.
5. This tube is similar to the 6AL5, 6AK5, 6AV6 and 6AL6, but with higher gain and greater power handling capability.
6. It is a very reliable tube, and is usually available at reasonable prices.