I did a review of the common fender schematics and came to the following conclusions...
There's an easier way to do this.
Dave Funk's Tube Amp Workbook runs down Fender amp models. I don't know if the original intent was that the "5" in "5F6A" would stand for "50's" but it's convenient now to think of it that way.
Skip to the final number in the model designation. The is the amp #; the Champ is #1, the Princeton is #2, the Deluxe is #3, etc. The numbers were assigned in the probable order they were developed.
The middle letter is the revision. So a 5C3 Deluxe is an earlier variant that the 5E3 Deluxe.
Catches:
- You'll almost never see a schematic for a "5A-" anything, at least not in original form from Fender. My guess is the model designation system wasn't created until after the "A" versions had been superseded, especially since some of those amps were originally made in the late-40's (and generally with different names/model designations).
- Some models were introduced at a time when other amps were in their D or E revisions. As such, those models were typically first designated with an "E" (or whatever) even though it was the first version. An example is the 5E5 Tremolux. I owned a '55 Tremolux, the first year they were introduced (production #45), and it was designated a "5E5". Interesting sidenote, you'll never see an original schematic for a 5E5, because soon after, the 5E5-A revision was released. The only change was moving the trem on switch from the Depth pot (where it made some sense) to the Speed pot.
At the start of the 60's, models were revised and all began with "6G-" even those who never went through an F variant (like the 5E3 being revised to the 6G3).
Throughout the 50's, there were a lot more variations between models. So it's easiest to follow changes to a single model. That's because depending on the amp, you can generally find differences between different "D" or "E" variants (some small, some large). Things somewhat converged during the early 60's, but when the blackface amps were released, Fender pretty much evolved to 1 standard circuit, with exceptions for special application. These amps largely varied in the size/number of output tubes and size/number of speakers. A side benefit to the convergence, from a marketing perspective, is that the entire line essentially had "the Fender sound".