It consists of a minimum of two coils, the primary and the secondary, wound on the same core.An alternating current in one winding creates a time-varying magnetic flux in the core, which induces a voltage in the other windings.From 1969 to 1983 the date code was after the serial number.From 1984 to 1992 the model number was first, then the date code, then the serial number.In it's simplest form a vacuum tube can be created to operate as a diode: a device that conducts current only in one direction.A third element called a "control grid" can be added to the design which provides the ability to amplify a signal.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.
Many musicians prefer to play vintage Fender, Marshall and Gibson amps.Amps should only be serviced by a qualified technician.Is there a website or anything where I can figure out how old a Marshall amp is?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.
I just scored a 2205 which is a JCM 800 two channel 50 watter with 'verb.