Smallest power tube commonly available, delivering around 7 – 12 W per tube. They run hotter than 6V6 due to their smaller surface area and higher heater current. Soundwise they’re closer to 6V6 and 6L6 than to EL34 despite the name when compared in the same amp. However, EL84 amps might in general have their own recognizable character due to the typical design of the output stage.