7247 is a dual triode vacuum tube manufactured by Philips in the 1930s. It has two identical triodes that are used in circuits to create amplifiers, oscillators, and mixers. The 7247 is used in amplifiers due to its low noise and low distortion. It was originally used in radios and has been used in many other applications since. Its low plate voltage rating of 100V makes it suitable for low-power valve amplifiers. This tube is also helpful in creating feedback-based amplifiers. Its reputation as a reliable, long-lasting component has made it a part of many vintage sound equipment designs.