Silverface
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. Other blackface cosmetic features were retained. The first silverface Twins used the blackface AB763 circuit until May 1968, when Fender switched to the AC568. Since the tube complement was the same, Fender just used up their stock of printed tube charts saying AB763 until they ran out.
The Twin Reverb, along with all other silverface models, had an aluminum frame (trim) surrounding the sparkling blue grillcloth from late 1967 to 1969. Early silverface amplifiers made between 1967 and 1968 had black lines on the brushed aluminum control plate, still retaining the '60s "tailed" design. This feature was offered on models produced prior to the "tailless" period in 1973. Some later models came with an unusual silver grillcloth with sparkling orange threads ("orange sparkle"); a black grillcloth was even fitted on some production runs.
The rating of the amplifier's output power was also upgraded to 100 watts, and between 1977-1982 the power was increased to 135 watts.
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