You’re looking at a vintage or near-vintage Fender amp—it’s got a silver control panel with blue lettering, but how old is it? If you have access to the serial number on the back of the chassis, there are several online resources that will help, although I have found that they still have some contradictory or incomplete information. Regardless of serial number, you can still narrow down or rule out certain ages by some features or design changes during the silverface era. These changes didn’t typically start and end with the calendar year, so the years I mention will be somewhat approximate. Also realize that these changes don’t always apply to the same models at the same time, which I will try to point out when I am aware of them.
- The first two years of silverface production (the last two years of the 1960’s) saw the grille of the amps surrounded by a narrow metal trim frame, popularly known as a drip-edge.
- Up until about 1972, the high-wattage Fender amps did not have a master volume control.
- This master volume control later gained a pull-boost function on the high-wattage models in about 1974. Also note that the mid-wattage Fenders (Pro Reverb, etc.), gained the master volume and pull-boost together in the mid-1970’s.
- In about 1977, the larger Fenders also switched to using ultralinear transformers (sometimes shortened to UL, and not to be confused with the Underwriters Laboratories label applied to electronic products in general). This raised the rated output power of the 40-watt and the 50-watt models to 70 watts, and the 100-watt models to 135 watts. This was actually spelled out in the model name of the Bassman 100 as it was renamed the Bassman 135.
- The Fender logo, mounted on the top left of the grille, started in the silverface era with a “tail” underneath the logo, but lost the “tail” around 1974 for most amps.
- One thing to keep in mind is that most of these changes affected the larger Fender amps to a greater degree than the small amps like the Champ or Princeton. Most of these small Fenders I’ve seen have hardly any visual differences during the 1970’s.
With all the details and changes over the years, the silverface Fenders can sometimes get confusing when trying to figure out exactly what you’re looking at. This is a quick way to track the bigger changes, and hopefully will make buying or evaluating one easier.