In the fall of 1965, Fender switched from stamping these numbers in black ink, to dark green ink.
This information original was found on The Unofficial Ampeg Page ( which appears to be dead.
The following lists provide an accurate record of the date codes used.
The first electronic loudspeaker designs were introduced in the 1920’s, and while there have been many improvements in component materials over the decades, not much has changed in the basic functionality of a loudspeaker: a permanent magnet interacts with an electromagnet (voice coil) to move a cone back and forth to produce sound waves. Morgan has a Bachelor’s degree in Chemistry from the University of Georgia and a Ph. in Physical Chemistry from Emory University in Atlanta.
Greg is a long time Fender collector who is very knowledgeable not only in the details, but in the circuitry as well.
Vintage 1959 Fender tweed Bassman, classic 5F6-A circuit. Mid-60s factory Top Boost AC-30, designed by Dick Denney, JMI production, grey panel, original transformers, housed in a very authentic North Coast repro cabinet riding on a beautiful repro chrome dolly, Weber Blue Dog alnico...
Here we have a vintage 1951 Fender TV-front tweed Deluxe amplifier, an early piece of Fender history.
Serial number 3648, original Jensen P12R alnico magnet speaker, just reconed.
Transitional cosmetic, blonde tolex and blackface circuit. Fender's top of the line piggyback amp, blackface AB763 circuit, 85 watts, 4x6L6, solid-state rectifier, 2 channels, tremolo, matching cabinet with JBL 1x15" loudspeaker, clean and original including tilt-back legs, sliding...
Here we have a vintage 1966 Fender Bassman head, in good shape.