The main focus of this article will be speakers found in Fender amps, but before we get into that topic let’s go over a few other areas first.
Early silver face amps: Part 2 went into this topic in some detail, but since that article was printed, I have been asked a of questions about this subject.
There are also exceptions to the rules where Fender delivered non-standard speakers in special orders, Christmas campaigns etc. See our Buyer’s guide to vintage Fender amps for a guide and picture gallery of the known original speakers in the blackface and silverface amps.There are other methods used to date "Silverface" amps, you will need to get the date codes from your speaker frame, tube chart or pots.Pots and speakers are usually stamped with a 6 or 7 digit code that can be dated as follows: The first 3 are the manufacturers code 137xxx = CTS 304xxx = Stackpole 140xxx = Clarostat 134xxx = Centralab 381xxx = Bourns 106xxx = Allen-Bradley Speaker Manufacturers codes 67xxx = Eminence 117xxx = Credence 137xxx = CTS 220xxx = Jensen 270xxx = Quam 285xxx = Rola 328xxx = Utah 391xxx = Altec/Lansing 433xxx = Cleveland 465xxx = Oxford 649xxx = EV 1098xxx = Pyle The next number(s) is (are) the year.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.The fourth digit is the year (a second digit was added here later to help distinguish between 50′s, 60′s and 70′s), and the final two correspond to the week.So looking at the photo of the speaker on my tweed Fender Champ we see a code of 465-909 (we’ll cover the 8EV-29 code in a later post).If three digits are present, the first digit would refer the units of the year i.e. If four digits are present, the first two digits refer to the year i.e. The last two digits would refer to the week of the year i.e.("26" would mean the 26th week or approximately June).These date codes will contain two letters of the alphabet which refer to the year and month of production, and may be interpreted as follows: In the absence of the rubber-stamped date codes, EIA numbers taken from the transformers may allow you to determine the date of production of your amp.These numbers always begin with "606" , and are followed by three or four digits in various combinations.All of this corresponds to the two letter date code stamped on the tube chart, IC (I for 1959 and C for the third month of the year, March).I’m feeling pretty good that the dates all line up on this amp and I have an amp made in March 1959 with an original Oxford speaker.If you are reading this there is a good chance that you are already familiar with the two letter date code used by Fender to date their Champs from 1950′s and 60′s.