Dating a fender amplifier with serial number

These are marked with EIA code “606” which is the company number for Schumacher.

only come into play when you’re trying to value the amplifier in the Blue Book for Guitar Amplifiers per the model description that is provided.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.They are not of a concern with dating as only the 2 letter date codes on whichever chart or sticker and the transformer number comes into play for that....There are other ways but the above is a more accurate method.