The Ampeg SVT is a bass guitar amplifier designed by Bill Hughes and Roger Cox for Ampeg and introduced in 1969. The SVT is a stand-alone amplifier or "head" as opposed to a "combo" unit comprising amp and speaker(s) in one cabinet, and was capable of 300 watts output at a time when most amplifiers could not exceed 100 watts output, making the SVT an important amp for bands playing music festivals and other large venues.
The SVT has been through many design changes over the years but is still in production today. While the SVT could be used with any 300 watt, 2- or 4-ohm cabinet combination, Ampeg recommended that it be used with a pair of sealed 8x10" speaker enclosures because one cabinet could not handle the power of the SVT. It was not until 1980 that the speakers in the enclosures were updated to a power handling rating of 350 watts, allowing a player to use an SVT head with only one cabinet.[1]
SVT originally stood for Super Vacuum Tube, but Ampeg has since revised the meaning of the initialism to Super Valve Technology,[2] with the word "valve" referring to the vacuum tubes (called "valves" in Britain and some other regions) used in the amp.