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.
It’s unknown if the tweed covering was a mistake (“Oops, I thought this was a 4x10 Bassman cabinet that I was covering”) or intentional, perhaps as a special order.
The raised “Fender” grille logo lost its tail around 76.
There are exceptions to this rule like the the Bronco.
Fender often used the same circuit for many years so this is not a very accurate method for amp dating.
The code is simple, the first two letters are the revision, where AA is the first revision, AB is the second, etc.
These are marked with EIA code “606” which is the company number for Schumacher.
Well, this universal “truth” was debunked when we found a bunch of amps with transformers made by the Better Coil and Transformers company.Serial Number: There is no information readily available for dating Fender amps by serial number but there are people working on it. Circuit Code: In 1963 Fender stoped using model numbers to identify schematics and began using the model name and an assigned circuit number.These circuit numbers which are located on the tube chart can be usefull for getting a rough date on an amp. I promise the tables will still be there after you finish reading. Okay, I know you’re all just dying to skip ahead to the serial number tables but try to contain your excitement and read through the article first.The code follows the format: XXXYY ZZ where: XXX = a two or three (possibly four on newer amps) digit number indicating the manufacturer.