I turned to the Internet to do some more networking which resulted in a major turn of events as I met two individuals who have become instrumental partners in this project: Greg Huntington and Devin Riebe.Greg is a long time Fender collector who is very knowledgeable not only in the details, but in the circuitry as well.New panels made after the CBS acquisition were used beginning in April 1965 and say "Fender Musical Instruments." So, if you have January 1965 amp, it will have a Fender Electric Instruments panel whereas a January 1966 amp (even though it has that green "OA" date stamp) will have Fender Musical Instruments. Although the database doesn't have thousands upon thousands of entries, we are seeing some interesting patterns emerging that will help date amps by serial number. The early amps (woodie and tweed) had serial numbers handwritten on the tube chart.
Greg and Devin's experience meshed well with mine since I'm essentially the blackface/silverface amp guy (amps made between 19) in the group.
Additionally, Greg and Devin also had data that they had been collecting from Fender amps for years. Everything is confidential, we don't make record of who owns what amp in the database.
For example if you have 606-432 on a transformer, you can tell that it's a Schumacher transformer from the '606', the year is either 1974, or a 1964, from the '4', and the '32' is the week of production.
The model type, or number, is sometimes stamped on the transformer frame, or bell, as well; for example 022798, telling us that this is the power transformer from a Fender Super Reverb.
If the transformer was read from a silverface Vibro Champ we can deduce it was made in 1974 – almost…
Remember that this is when the transformer was manufactured.Sometimes there is also another series of numbers stamped on the piece, this is the OEM (Original Equipment Manufacturer) part numbers above or below the EIA code, and in some cases parts makers elected not to include the EIA codes, so not all parts have them.These "Code" formats were not completely standardized, but a little deciphering will generally yield the info that's needed to identify the transformer in question.These are usually in the form of a six-digit number with the following formatting scheme: The first three digits represent the manufacturer code, the next digit represents the year of production and the last two digits represent the week of production.Thus as an example 606452 is a transformer code: 606 tells us it is a Schumacher transformer made in either 1964 or 1974 and and it was built on the last week of December.These 1965 codes begin with the letter "O." The code for the year 1966 is "P." However, someone in the factory apparently forgot to switch the stamper from "O" to "P" in January 1966.