It’s simple: the 5 stands for 5 watt pure tube and 18 stands for 1 x 8″speaker. A trip in the time machine….A champ the way it should sound! The 518 is a tribute to the Champ and after 40 years, this little gem continues to delight players from being an outstanding practice and studio amp. This is a perfect choice for club dates when paired with an efficient external speaker cabinet. Did you know that the origianl ’50′s Champ has been the mainstay of many of the Stones recorded tracks for decades? The 518 is our most affordable amplifier and available with a 12 inch speaker in a larger cabinet – the Victoria 5112.