Potentiometer Codes On Gibson Bass Guitars
 | | Wiring loom from a 1977 Gibson Grabber. Notice the pot code 1377719 which indicates that it was made by CTS in the 19th week of 1977 |
Just like the basses themselves, the potentiometers (the volume and tone dials) have a serial number stamped into them. This is an invaluable tool for dating vintage Gibson Instruments. The serial numbers that Gibson used were cryptic to say the least - whilst the pot codes had a simple system in which the date of manufacture was an integral part of the serial number
How to Read Pot CodesMost Gibson basses use pots made by a company called CTS (Chicago Telephone Supply), which has a manufacturers code of 137. CTS codes are in the format 137-year-week. So in the example pictured 1377719 would indicate a CTS pot, manufactured in the 19th week of 1977. Gibson did use pots by other manufacturers, but rarely - one such manufacturer is Centralab, code 134.
The other number on the pot 70-031 is the Gibson part number. For more information about part numbers, and ratings, see the VintageGuitar Gibson Pot Database
When dating an instrument using pot codes, it is important to remember that pots can be changed, so any conclusion must be in line with other features, such as hardware and serial numbers.
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