In the table below, for example, a “CE” date code indicates a production date of May 1992.On the inside of the cabinets of most Fender amps made after 1950 and before 1970, there might be a “tube location” sticker.on a Bass-Master might indicate that the amp is from 1965 or 1966, before the four-digit serial numbers were used.The circuit in [that amps] is built on a phenolic turret board instead of the Fender style fibre board used [later.] [...] it appears that Traynor/Yorkville used three digit serial numbers up until 1968.These numbers always begin with “EIA 606,” and are followed by three or four digits in various combinations.If three digits are present, the first digit refers to the year (i.e., a “7” would mean 1967).For example, EIA 606-4-21 would denote the 21st week of 1964.It is also advisable to add about 6 months to the date to allow for time these parts may have spent in inventory storage.
In general, Fender amps that don’t have rubber-stamped tube sticker date codes have EIA numbers on their transformers that might enable determination of the production date.
If you are unable to determine the approximate production year of your amplifier using the above charts, there are other means of dating Fender amps.
Several excellent books are available that contain reliable and invaluable information on the history of Fender amplifiers. To use these books most effectively, you’ll need to get the date codes from the speaker frames and potentiometers, and as much other detailed information as you can find about the specs and features of your amp.
If four digits are present, the first two digits refer to the year (i.e., a “66” would mean 1966).
The last two digits refer to the week of the year (i.e., a “26” would mean the 26th week or, roughly, June).