Electronic components such as transformers, potentiometers, speakers, and some capacitors are often stamped with a date code, which indicates the manufacturer and the manufacturing date.
The code follows the format: = a number from 1 - 52 indicating the week of manufacture.
Remember, your amp is newer than the newest component.
For example, if you find pots from late ‘64 and transformers from early ’65, you can be pretty sure your amp is a 1965.
The following chart, was originally printed in VG magazine, by Gerald Weber.
If you see any data that is not listed here or notice any errors, for 1970’s and earlier Fender amps, please send us an email and we will update the chart.
Neither the date nor the value can be determined from the serial number.
Fender’s amps, unlike their guitars, are not tracked by the serial number.
: The transformer number tells you when the transformer was made and not necessarily the date the amplifier left the Fender Factory, the “2 Letter” date code on the Tube Chart or QA Sticker actually tells you that and that makes it the most accurate option for dating the month and year it was made....The type of face, grille cloth, type and number of speakers, type and number of knobs, etc.only come into play when you’re trying to value the amplifier in the Blue Book for Guitar Amplifiers per the model description that is provided.They are not of a concern with dating as only the 2 letter date codes on whichever chart or sticker and the transformer number comes into play for that....There are other ways but the above is a more accurate method.Per Blue Book and Fender Consumer Relations Department. By entering this site you declare you read and agreed to its Terms, Rules & Privacy and you understand that your use of the site's content is made at your own risk and responsibility.For more information, please visit this site: Fender Support kcbuck So... Some things are very obvious such as non-original or reconed speakers, non-original transformers, replaced pots, re-tweed, re-tolex, re-grill, etc.and these changes are often disclosed and of a non-malicious nature.Other things to look for include chasses placed in cabinets from a different year, “doctored” tube charts, non-original control plates (usually reproductions) on silverface amps, original transformer bell ends (they have correct date codes, of course) on non-original transformers, and non-original knobs (either repro or silverface knobs on blackface amps).unusual things can be found such as the empty “Pulse Adjust” hole on the rear of early ’60 brown amps, the “middle” volume control, use of tweed style grill cloth, strange non-documented transitional circuits, and changes in tolex color including the super-rare cream colored “brown” tolex that is found on some late ’60 amps. Given that people may refer to this information seeking specific production quantities of amps they are curious about, it should be pointed out that the serial numbers apply to chassis types, and not specifically to amplifier models.Looking at serial numbers next to the ’60 5G5 brown Pro Amp for example, we see numbers ranging from 00001 to 02000, suggesting that there are 2000 of these amplifiers made in ’60.