There are some easy ways to find out when your vintage Fender was manufactured. First, to get a general idea,there’s the appearance/style of the amp. There are some exceptions and some overlap, but the general idea is this: Tweeds (early 50’s to very early 60s), Browns (1960 – 1962), Blondes (1962 – 1963), Blackface (1963 – 1967), and Silverface (1967 – 1981). Up until the end of the blackface era (1967), all amps left the factory with a tube chart that had a two letter date code stamped on it.
TUBE CHARTS:
The tube chart date code works like this: the first letter indicates the year and the second letter indicates the month. So if your blackface amp has a date code stamp of OB, it was made in 1965/February. If your tweed champ is stamped HH, it was made in 1958/August.
A – 1951 A – January
B – 1952 B – February
Try the serial number. Dating by serial number, while less accurate, can be of some use. Stamped on the metal backing of most amps is the serial and production number. It is typically in the A00000 format. Up to 1981, Fender's serial numbers were genuinely serial within one amp type. Thus, for a given amp (say, the 5E1 Tweed Champ) they started with a definite number, in this case C00001, and just kept adding '1' for each new Tweed Champ until the model was discontinued - in this case approximately C23000 nine years later (info from Greg Gagliano).
C – 1953 C – March
D – 1954 D – April
E – 1955 E – May
F – 1956 F – June
G – 1957 G – July
H – 1958 H – August
I – 1959 I – September
J – 1960 J – October
K – 1961 K – November
L – 1962 L – December
M – 1963
N – 1964
O – 1965
P – 1966
Q – 1967
TRANSFORMER DATE CODES:
Another way to get a close estimate of when your amp was made is to read the codes on the transformers. Most post tweed Fenders had trannys manufactured by Schumacher.
They used a code like this: 606 – 645
Fender Amp Serial Number Search
The date is in the last three digits, after the 606 – . The first of the three digits tells us the last digit of the year (unfortunately not decade specific) and the last two numbers tell us the week. In the above example, the transformer was made in either 1966 or 1976, week 45. Now if it’s a blackface amp, it’s a safe bet that 6 means 1966. If it’s a silverface amp, that 6 indicates 1976.
This code can be found on the power transformer, output transformer, choke, and reverb transformer. They are all usually within a few months of each other. Use the latest one to give you a good idea of when it was made. For example, if your silverface super reverb has transformer codes all from 1974, it was made in 1974! Let’s say the weeks are 27, 29, 33, 41. Based on the last number (45), it’s safe to say it was made in late 1974.
Fender Amp Date Serial Number
Many silverface and some blackface amps have the exact week, month and year stamped insie the chassis.
FENDER SERIAL NUMBERS:
Fender Blues Jr Serial Number Lookup
Here’s a link to a great webpage that has compiled the dating list forFender Serial Numbers.