Dating fender guitar amplifiers
These are marked with EIA code “831” and are most prevalent during the 1966-68 time period.Some examples include a '66 Princeton Reverb and ’66 Pro Reverb with Better Coil output transformer, a ‘66 Deluxe Reverb and ‘67 Twin Reverb with Better Coil reverb transformer, and a 1968 Vibro Champ with Better Coil trannies.These units look, and apparently sound, just like the Schumacher-made units so it’s easy to overlook that “831” code.Working at FMI – I was able to interview a fellow (who wishes to remain anonymous) who worked at Fender in 1972-73 in the amp department.Also note the vertical black lines on the control panel (found on earliest silverface amps) and the large ceramic power resistors coming off the power tube sockets which indicates the AB568 circuit. But really, these cabs were large because they were of a “special design” that “greatly improves tone and volume without distortion, and permits optimum performance of the speakers.” At least that’s the reason according to the ’69 catalog.Also, another thing I’ve never seen before is a what appears to be a shipping tag of some sort (see photo).They were something to behold, all chatting away while soldering so quickly, it didn't hardly seem like they were looking at the amps.
The Australian Fender Distributor then installed 240V - 110V stepdown transformers in the bottom of the cabinets.
I promise the tables will still be there after you finish reading.
Okay, I know you’re all just dying to skip ahead to the serial number tables but try to contain your excitement and read through the article first.
These are marked with EIA code “606” which is the company number for Schumacher.
Well, this universal “truth” was debunked when we found a bunch of amps with transformers made by the Better Coil and Transformers company.
A 1957 tweed Vibrolux was reported with a tube chart printed with circuit “5E3” (tweed Deluxe) instead of the correct 5F11 (see photo).