Lots of different speakers were used in the blackface and silverface era Fender amps.
In a BF Vibrolux Reverbs you could have either Jensen, CTS or Oxford, the BF Super Reverbs had Jensen, CTS, Oxford or sometimes JBL, the BF Pro Reverb had Jensen, Oxford or Utah, .
typically 400V or more, and a lower voltage for the tube filament, typically 6.3 or 12.6V. Dating Marshall Amps In 1969 Marshall introduced a date coding system.
Some of the older Marshall amps have an inspection sticker on the top of the chassis which usually has the day, month and year the amp was actually made or inspected. Note, "A" Date Code ran for 18 months (July 1969 to December 1970) so the "B" date Code was never used and has been omitted. The serial number is generally located on the back of the chassis but from 79 to 80 it was on the front panel.
The resulting negatively-charged cloud of electrons is called a space charge.
These electrons will be drawn to a metal "plate" inside the envelope if the plate (also called the anode) is positively charged relative to the filament (or cathode).
Other configurations are also possible including the Pentode, a tube with 5 active elements providing an additional amplification factor.
There are a large number of tube varieties and uses.In the silverface era Eminence, Oxford, Utah and Rola were more often used and Jensen was phased out.Even at we struggle with keeping a correct amp and speaker model overview. For most purposes, the vacuum tube has been replaced by the much smaller and less expensive transistor, either as a discrete device or in an integrated circuit. and Canadian English) or (thermionic) valve (outside North America) is a device generally used to amplify, or otherwise modify, a signal by controlling the movement of electrons in an evacuated space.It consists of a minimum of two coils, the primary and the secondary, wound on the same core.