Editing Tube socket (section)

=== Noval base ===
The nine-pin miniature '''Noval''' B9A base, sometimes called button 9-pin, B9-1, offered a useful reduction in physical size compared to previous common types, such as octal (especially important in TV receivers where space was limited), while also providing a sufficient number of connections (unlike B7G) to allow effectively unrestricted access to all the electrodes, even of relatively complex tubes such as double triodes and triode-hexodes. It could also provide multiple connections to an electrode of a simpler device where useful, as in the four connections to the grid of a conventional grounded-grid UHF triode, ''e.g.'', 6AM4, to minimise the deleterious effects of lead inductance on the high-frequency performance.

This base type was used by many of the [[United States]] and most of the European tubes, ''e.g.'', [[12AX7]]-ECC83, [[EF86]] and [[EL84]], produced commercially towards the end of the era before [[transistor]]s largely displaced their use.

The IEC 67-I-12a specification calls for a 36-degree angle between the nine pins of 1.016&nbsp;mm thickness, in an arc of diameter 11.89&nbsp;mm.

European tubes of this type have numbers 80-89, 180-189, 280-289, 800-899, 8000-8999.