(Ver.1.0) Beta
Stamped on every potentiometer (volume and tone pots) is a six- or seven-digit source code that tells who made the pot, as well as the week and the year. The source dating code is an element of standardization that is administered by the Electronics Industries Alliance (EIA). The EIA assigns
each manufacturer a three-digit code (there are some with one, two or four digits).
When dating an instrument by the ‘pot code,’ keep two things in mind: The potentiometers must be original to the piece (new solder, or a date code that is off by ten or more years is a good giveaway to spot replacement pots); and the pot code only indicates when the potentiometer was manufactured! If the pot is an original, it indicates a date before which the guitar could not have been built – so it’s always a good idea to have extra reference material around.

Finally, a word of caution: This method applies only to American made pots and not all potentiometer manufacturers subscribed to
the EIA source code date. If the code does not fit the above criteria, don’t force it and skew your dating results.