Guitarists worldwide revere the legendary Fender Twin Reverb for its brilliant clean tones and luscious spring reverb. Although Fender never kept serial number records of its amps, you can determine the approximate year your Twin Reverb was built by matching it against the cosmetic changes the amp has gone through. You can also determine the origination year from the amp's serial number thanks to extensive research done on Fender amps by Greg Gagliano, a former contributing editor to "20th Century Guitar" magazine.
Look at your nameplate. If your Twin Reverb has a black nameplate on the front, it was manufactured during Fender's "Blackface" era, which was from 1963 to 1967. If your amp has a silver nameplate with blue labels, it was built during Fender's "Silverface" era, which began 1968. If the label reads "Fender Electric Instruments," it was built before 1965. If it reads "Fender Electric Instruments" it was built sometime after Fender was sold to CBS, which was in 1965.
Inspect the grillcloth. Twin Reverb amps made between the years of 1967 and 1969 had aluminum trim surrounding the sparkling blue grillcloth on the front of the amp. Earlier models had black lines on the aluminum control plate.
Check the wattage and volume knob. From 1977 to 1982, the Twin Reverb's power was increased to 135 watts. Those manufactured in 1973 and later also featured a push-pull master volume knob. From 1982 to 1986, the name was the Twin Reverb II and the power was changed to 105 watts. The black nameplate was also brought back on these models.
Look at the knobs. In 1987, The Twin Reverb II was replaced by The Twin, which featured red knobs, a separate gain channel and a switchable overdrive. The so-called "Red Knob Twins" were made until 1994.
Check the serial number and consult the table listed here. Use the numbers as a guide only, though, as there have been exceptions and breaks to the numbering scheme that Fender used throughout the years.
Twin Reverb AA763, AB763 (blackface) A00100 to A01200 – 1964 A01200 to A04300 – 1965 A04300 to A07000 – 1966 A07000 to A10400 – 1967
Twin Reverb AB763, AC568, AA769, AA270 (silverface) A10500 to A11300 – 1967 A10500 to A16500 – 1968 A16500 to A21400 – 1969 A21400 to A25600 – 1970 A25600 to A37000 – 1971 A37000 to A50500 – 1972 A50500 to A68000 – 1973 A68000 to A99999 – 1974 A81000 to A99999 – 1975
B01000 to B15000 – 1975 B15000 to B68000 – 1976
0100 to 3400 - 1970
In 1992, Fender introduced the classic '65 Reissue Twin Reverb model. As of 2010, the company also offered an updated version of the Twin Amp in their Pro Tube line of guitar amplifiers.