Abbreviation for Junction Field Effect Transistor – an electronic component. A JFET is a specific type of FET not too dissimilar from the MOSFET, which is popular in audio designs. However the JFET also has some similarities to traditional bipolar transistor designs that can make it more appropriate for use in some audio circuit designs. In general FET’s tend to sound more like tubes than typical transistors. The various types of FET’s have different operational characteristics within that paradigm.