Man has always tried to increase the volume of his voice to the maximum. In order to do so he has used different techniques. One such technique used to increase the magnitude of the voice is vacuum tube amp. A vacuum tube is the amplifier which uses the vacuum tube to increase the amplitude or the power of the signal. This technique was used in the 60s and 70s. These amplifiers were used to amplify the frequencies below microwaves. This technique was replaced by the solid amplifier techniques.
How does the vacuum tube amplifier work?
A vacuum tube amplifier is the device which works on Tran’s conduction, in which voltage controls the current. A cathode is heated within the vacuum bulb which results in the boiling of electrons. The cathode is surrounded by the metal cylinder which is known as metal plates. The power supply between the cathode and the plate is connected in such a way that the plate is more positive. The electron covering the cathode is made to collide with the plate in the open space.
The flow of electron from the plate to the cathode through the battery is established. If you can place a metal mesh between the cathode and the plate then the flow of current could be shut off completely. Now resistor is placed in series with plate. As the plate current is varied, the voltage in the resistor changes in the same proportion. A small change in the grid cathode voltage can result in large change in the voltage in the resistors thus resulting in the amplifying of the triode.