The 6V6 is an Octal based beam-power tetrode, introduced by Radio Corporation of America RCA United States during 1937. The 6V6 is similar to its larger sibling, the 6L6. The 6V6' strength over the 6L6 was the lower input powere required and the consequent ability to run on lower rated power supplies and consume lower heater current, sure, the 6V6 generated a lower power output but in push pull, fpor car radios and domestic radios it became te valve of choice to replace power pentodes such as the 6F6 had previously been used. The 6V6 required less heater power and produced less distortion than the 6F6, while still offering higher output in both single-ended and push-pull configurations.

In an audio output stage, a single 6V6 can be used to produce about 3W (continuous), and a push-pull pair about 10-12W. The 6V6 was introduced in both metal and shouldered glass tubes. RCA was promoting the superiority of its metal tube designs in the second half of the 1930s and the metal variant was produced in huge quantities. Other manufacturers preferred the glass envelope presentation either as the 6V6GT, the 6V6GTA with controlled heater start up pr the 6V6GTG with glass base rather than the more usual pinch stem seal.

6V6 valves are renowned for their longevity and have been found to give sterling service even when run beyond their maximal performance envelope. Because of this, the 6V6 became popular in musical instrument amplifiers and to this day, Chinese, Slovakian and Russian valve manufacturers keep the 6V6 in production. However, the best devices of type are the vintage beauties that

In the Soviet Union a version of the 6V6GT was produced since the late 1940s which appears to be a close copy of the 1940s Sylvania-issue 6V6GT - initially under its American designation (in both Latin and Cyrillic lettering), but later, after the USSR had adopted its own system of valve designation, the valve was thence labelled 6P6S (6П6С in Cyrillic.)

Some key classic guitar amplifiers the 6V6 does duty in the output stage are:-

Clark Amplification 5E3 Cabinet
Fender 57 Champ Reissue
Fender Champion 600 (new)
Fender Deluxe 1957 Reissuse 2007
Fender Deluxe Reverb
Fender Musicmaster Bass Guitar 1970
Fender Princeton Reverb 1964 & Reissue 2008
Fender Tweed Champ 1960
Fender Vibro-Champ 1965
Gibson GA-20T 1959
Guild 66-J 1965
Magnatone 213
Marble Bluebird
RCA SP 20 amp
Sears Silvertone 1472
Silvertone 1331 1954-1957
SUPRO 1606 1955-1956
Swart AST
Victoria 5112 amp
Victoria Amp Model # 20122