Dating early Fender amplifiers is sometimes quite challenging.While dating Fender amps made before 1994 by serial number is all but impossible (as records of these numbers were never kept), all hope is not lost—the charts below should prove helpful in dating your Fender amp.
An updated version was introduced in 2006 as part of the "Vintage Modified" line.
We combined all of our information into a computerized database for this project and for the past 18 months have been slowly (sadly, very slowly) gathering information that we collect ourselves as well as from other people. What we need is the following: 1) Model name 2) Model number on the tube chart 3) Date code letters on the tube chart 4) Speaker codes (if speaker is original) 5) Transformer codes (if the amp doesn't have date codes on the tube chart) 6) Cosmetic features (flat/raised logo, tweed/tolex, blackface/silverface, rough/ smooth blond tolex, white/skirted knobs, TV-front/wide-panel, etc.) One very interesting and very important factoid has surfaced regarding the date code letters on the tube chart.
In the fall of 1965, Fender switched from stamping these numbers in black ink, to dark green ink.
First, it will be useful to you to understand the following five terms in order to choose the correct chart for dating your amp: refers to the two-tone woven fabric that covered many early amplifiers.
On early amps, this material was varnished to make it a more durable covering.