In most applications, the vacuum tube is obsolete, having been replaced decades ago by the bipolar transistor and, more recently, by the field-effect transistor .
Tubes operate at higher voltages than transistors.
At the highest power levels, some tube circuits have power supplies delivering several kilovolts. Vacuum tubes are making a comeback among audiophiles who insist that tubes deliver better audio quality than transistors. The major disadvantages of tubes include the fact that they require bulky power supplies, and the high voltages can present an electric shock hazard. Bringing you the best technology specific search engines.