The JJ EL84 has become one of the most popular EL84 valves used today. A favourite with musicians and amplifier manufacturers for their versatile application. Manufactured by JJ electronics, what used to be the Tesla name. The EL84 JJ projects a classic raunchy sound from Rock to Blues and Jingly warm clean tones. One of the most rebranded EL84's around today. You will see this valve In many different disguises. We don't believe In freezing (Cryogenic) these valves, hear them In their true natural form.