[citation needed] The Twin has seen a number of revisions since its introduction, both internal and external, with its designs sometimes varying greatly from one year to the next.
[2] Many notable musicians have used Fender Twin amplifiers, including Mark Knopfler, David Gilmour, Chuck Berry, Buddy Holly, George Tomsco of The Fireballs, Mike Oldfield, The Beatles[3] (1968 Twin Reverb amps using the AC568 circuit),[4] Jimi Hendrix,[5] Eric Clapton,[5] Peter Green, Jeremy Spencer, Danny Kirwan, Keith Richards, Mick Taylor, Steve Jones (Sex Pistols), Jerry Garcia (Grateful Dead), Eric Johnson, Joe Bonamassa, Junior Brown, Kurt Cobain and Tommy Emmanuel.
[6] The original version was an all-tube combo amplifier with dual 12" speakers and two 6L6 tubes for a rated output of 25 watts.
The entire line of Fender amplifiers from 1955 to 1959 (later for smaller models and Bassman) was uniform in this look—tweed or "airline linen" covering with a maroon with gold stripe woven saran grill cloth.
Like its predecessors, the narrow panel tweed Fender amplifiers used Jensen Alnico V Concert Series Speakers, for the most part.
Due to its volatile nature if broken, it was quickly superseded with a GZ34 rectifier but not duly noted on the tube chart until the second production.
The final 5F8-A Twin-Amp version, released in 1958 and produced into early 1960, had become the crowning achievement of Fender fifties amplification.
With such bursts of volume energy, often these top-of-the-line Jensen speakers would fail, and sometimes even burn out (smoke) voice coils.
Keith Richards has used these late model, high-power Twin amps on Rolling Stones tours with his own special design Celestion Alnico (similar to the G12-80) speakers to insure optimum live efficiency.
The exact plight of the Twin-Amp during the months between January and May 1960, however, remains open to considerable speculation, debate and study.
The re-emergence of the Twin-Amp in mid 1960 revealed a new aesthetic design that would become prominent among Fender's top of the line amplifiers, with the exception of the Vibrasonic-Amp.
By 1961, the Bandmaster, the Bassman and the newly debuted Showman were all covered in the new look exemplified by the late 1960 Twin-Amp: blonde tolex and maroon or "oxblood" grille cloth.
The Twin-Amp of this period (late 1960–1963) was manufactured with a variety of speakers including Jensen, Oxford and JBL designs.
The brown one still had the harmonic tremolo and early Vibroverb reverb circuitry with an extra tube and rear dwell control.
The blonde Twin Reverb Leo gave to steel player Red Rhodes for testing purposes at the famous Palomino Club (North Hollywood).
The first production Twin Reverb models used an unusual 7355 power tube (weaker cousin to the 6L6) as with their concurrent smooth blonde, blackface Fender Showman amplifier.
The more common speakers found in Fender Twin Reverb amps include Jensen C12Ns, Oxford 12T6s, JBL D-120Fs (an upgrade at the factory), Altec Lansing 417-8Cs, Utahs and, in later years, CTS and Eminence models.
In 1968 the Fender amplifier line switched from the original black faceplate to a new brushed aluminum faceplate with light blue labels (except the Bronco, which has red) and changed the color of the grillcloth from silver grey to silver with sparkling blue threads embedded within it, ushering in the Silverface era.
Early silverface amplifiers made between 1967 and 1968 had black lines on the brushed aluminum faceplate, still retaining the '60s "tailed" design on the amp logo, installed on the upper left side of the grillcloth.
In 1982 the Twin Reverb II was introduced to compete with Mesa Boogie's very successful products; it had an output rating of 105 watts and a return to Blackface era cosmetics albeit with a different, channel-switching cascading gain circuit with a more modern mid-range voicing and without the 'traditional' vibrato.
This version is very similar in cosmetics with the previous one but it introduces, for the first time, a full tube tremolo in a modern twin amp.
[15] In 1992 Fender introduced the '65 Reissue,[16] with blackface cosmetics and circuitry, an output rating of 85W RMS and 8Ω Jensen C-12K speakers.
The '65 Reissue is constructed with a printed circuit board and new 1/4" phone jacks for the footswitch pedal replacing the older RCA design of the vintage originals.
[18] In 2012, Fender released a series of three tweed-style amplifiers as an artist signature line, endorsed by Eric Clapton.
One of these amps is the Twinolux, a modified version of the 5E8 Tweed Twin that removed one channel, and added a tremolo effect, with an overall 40W output.