The 12DB5 is a vacuum tube used in many electronic amplifiers. It is a dual-triode vacuum tube with both triodes sharing a single cathode. It was developed by RCA in the 1950s and was used in audio amplifiers, which led to its popularity throughout the 1960s and 1970s. This tube is often used in guitar amplifiers to give them their characteristic sound. It has two plates and a total of 12 control grids, which gives it its name. The 12DB5 also has an oscillator grid, which makes it useful for tuning circuits. The gain of the tube is controlled by the amount of grid current applied, and the amount of plate current. This makes it a good choice for use in high-gain amplifiers. The 12DB5 also has a relatively low microphony noise, which is important in audio amplifiers.