JJ Electronic, s.r.o is a Slovak electronic component manufacturer, and one of the world’s remaining producers of vacuum tubes. They are based in Čadca, in the Kysuce region of Slovakia. Most of the products that JJ offers are audio receiving tubes. These vacuum tubes are mainly used for guitar and hi-fi amplifiers. In technical terms, JJ produces triodes, beam tetrodes and power pentodes. Double diode vacuum tubes for full wave AC-to-DC rectifiers are also produced. JJ also produces electrolytic capacitors for higher voltage purposes, generally for use in audio amplifiers. JJ also manufactures their own line of high-end audio amplifiers and guitar amplifiers. In 2015, the company sales amounted to EUR 8.5 million and net income came to EUR 3.8 million. Most production is exported to the United States.