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.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.

Dating Fender Tube Amps by Serial Number, Part I by Greg Gagliano Copyright 1997, 20th Century Guitar Magazine. Well, we'll get to good parts, but first a little background information is in order.

After reading Teagle and Sprung's excellent Fender amp book, I took them up on their challenge that maybe someday someone will compile enough serial numbers so that Fender amps can be dated that way. I contacted several Fenders collectors and dealers who were kind enough to supply me with data.

The 4x10 Bassman used the prefix "BM" while the piggyback Bassman used the prefix "BP." The reverb units have the prefix "R." In addition, the tweed Super, Pro and Bandmaster sometimes have the prefix "S" in the serial number.

The blackface and silverface amps (late 1963 to 1980) generally have serial numbers begin with the prefix "A." However, it appears that these were not used sequentially across all models.

Likewise, the brown/blonde Tremolux, Concert, Vibrasonic, Twin, Pro, Super, Vibrolux, Showman, Dual Showman, and Bandmaster used a sequential numbering independent of model, but as with Fender guitars, these were not used consecutively. The 1956 to 1963 Champ, Harvard, Princeton, Deluxe; the 1956 to 1960 Vibrolux, the 1956 to 1964 Bassman, and all the tube reverb units have their own serialization scheme.

The Champ has a "C" prefix, the Harvard an "H" prefix, the Princeton a "P" prefix, the Vibrolux a "F" prefix, and the Deluxe a "D" prefix.In March 1985, CBS sold Fender to a group of private investors.The serial numbers do not reflect this change - Fender continued to make instruments using existing serial number schemes.The biggest tip off would be the control panels which brings us to interesting factoid #2.After CBS bought Fender in January 1965, there were still plenty of control panels for various models that were in stock.Dating a guitar or amp can be a very exasperating experience.