Introduced in 1952, the Fender Twin featured a 2x12" speaker configuration, tweed covering, and two 6L6 power tubes supplying 25 watts of power. In '58, Fender boosted the power output to 80 watts with a quad of 5881 output tubes. Known as the "high power" Twin, these models have become the most sought after by both players and collectors. In 1963, Fender added reverb to the design and the Twin Reverb was born. Throughout the years, the ever-popular Twin has had many versions, including the Twin Reverb, Twin Reverb II, Red Knob Twin (often referred to as the "evil Twin"), and, most recently, the '65 reissue.