01 / ELECTRONICS
How to date guitar potentiometers
Look for an EIA manufacturer/date code on the metal casing. Do not confuse it with the resistance value or a part number. Photograph every visible line before interpreting it.
CTS · 1966 · week 30
| Digits | Meaning |
|---|---|
| 137 | Manufacturer: CTS |
| 66 | Year ending in 66; in this vintage context, 1966 |
| 30 | Week 30 |
Common maker prefixes include 137 = CTS, 304 = Stackpole and 134 = Centralab. Spaces or hyphens may separate the groups.
What if the year has only one digit?
In 304 825, 304 identifies Stackpole, 8 is the final year digit and 25 is the week. The code alone does not identify the decade. On the documented 1958 Stratocaster below, the surrounding evidence places it in 1958.
This dates the component, not the completed guitar. Parts can sit in stock, and replacements can be much later. Do not scrape a marking or disturb a solder joint just to expose a digit.
Technical reference: GuitarHQ’s source-date code guide. Photographic example: True Vintage Guitar’s 1958 Stratocaster study.
02 / FENDER NECK HEEL
How to read a vintage Fender neck date
First identify the format. A pencilled date, a month-name stamp and a later all-numeric code do not follow the same rules. The heel is the body end of the neck; use existing photographs or ask a qualified technician to expose it.
Pencil dates: read what is actually written
1960s month-name stamps
Stratocaster neck code · March · 1964 · nut-width category
The opening 2 is a model code, not the second day of March. B denotes a nominal 1⅝-inch nut width, not a neck-profile shape. Model codes changed over time, so do not extend this example to every Fender era.
Later eight-digit stamps
Precision Bass · fretted maple neck · week 10 · 1975 · Monday
This interpretation applies to the documented 1972–1980 system. Do not use it on the different 1969–1971 codes. Missing or blurred digits should remain unknown.
Technical reference: GuitarHQ’s Fender neck-date research, including Greg Gagliano’s work. Pencil-date photograph: True Vintage Guitar.
03 / PUTTING THE EVIDENCE TOGETHER
Three dates do not have to be identical
Imagine a guitar with a March 1964 neck stamp, late-1963 pot codes and a serial falling within a 1964 range. Those observations can be compatible. They are a starting point for checking the assembly, not a certificate of originality.
| Observation | What to record | What it does not prove |
|---|---|---|
| Neck marking | Full code, clear photo, interpretation | The body’s age or shipment date |
| Pot codes | Each code separately; unreadable digits noted | That the electronics were installed at the factory |
| Serial number | Exact characters, location and possible ranges | That all parts belong together |
| Repair history | Invoices, replaced parts and dated photographs | Undocumented work elsewhere on the instrument |
If one pot appears much newer, investigate that component and its connections before redating the entire guitar. If two clues conflict, keep both in your notes and seek an explanation.
Original explanations by The Real Deal Guitar Shop, with the technical and photographic sources credited above. Reference photographs depict third-party instruments, not pieces offered by this collection. Updated 16 September 2026.