There are some exceptions and some overlap, but the general idea is this: Tweeds (early 50’s to very early 60s), Browns (1960 – 1962), Blondes (1962 – 1963), Blackface (1963 – 1967), and Silverface (1967 – 1981).
Up until the end of the blackface era (1967), all amps left the factory with a tube chart that had a two letter date code stamped on it.
There are some easy ways to find out when your vintage Fender was manufactured.
With bottom-end headroom characteristic of 6L6 tubes and a versatile all-12AX7 tube preamp, the Hot Rod Deluxe III amp offers luscious Fender spring reverb, an effects loop and more.
If you want to add a little output, fullness, and stage coverage, you can even add a matching 1x12 extension enclosure to your Hot Rod Deluxe III.
Whether it’s a vintage amp or a recent model such as this Fender Pro Reverb, hum can have several causes.
Possible culprits include the preamp tubes, the power tubes, the hum balance resistors, and the power supply caps.
Some things are very obvious such as non-original or reconed speakers, non-original transformers, replaced pots, re-tweed, re-tolex, re-grill, etc.