The JJ Electronic KT88 is a sonically faithful reproduction of the original tubes with a robust construction encased in a thick glass envelope. The JJ KT88 delivers a powerful 42 Watts with plenty of headroom to spare. This tube has a tone that is warm and lively with a detailed and balance response. The JJ KT88 is an excellent choice for Hi-Fi stereo equipment as well as guitar amplifiers. It can be used in place of 6550 tubes.