Tip - How Does a Tube Amplifier Work? | eHow

How Does a Tube Amplifier Work?. Tube amplification became possible after John Ambrose Fleming invented the first vacuum tube, under the name the kenotron, in 1904. The first valve had two electrodes, earning it the name diode. This device, however, was not used for amplification. Its main purpose was to receive radio signals, as it didn't have the...