The Fender Reverb Unit (6G15) was a tube, spring reverb-equipped effects unit made by Fender. The Reverb Unit was originally introduced in 1961. It was discontinued in 1966 and was replaced by a solid-state model.[1] The unit features three controls: Dwell, Mix and Tone and is run by two pre-amp tubes and a power tube. Physically the unit looks like a small ampilfier head and since the early '60s the unit has become synonymous with surf music.
The tube reverb was reintroduced in 1976 with a silver control panel ("Silverface"). It was discontinued in 1978.[2]
A reissue of the original tube reverb was introduced in 1994. It is available with white, black or brown tolex. Fender also now makes a tweed covered Reverb Unit to match the tweed amplifiers of the 1950s.[3]