Fender Pot Codes Dating Guide: Read the Hidden Year Stamp

Fender Pot Codes Dating Guide: Read the Hidden Year Stamp

Fender pot codes are some of the most useful clues hidden inside a vintage guitar. Every potentiometer stamped into a Fender control cavity carries a manufacturer code and a production date that can narrow a guitar's build window to within a few weeks. When the serial number is vague, the neck date is smudged, or the parts look like they have been swapped, the pots can settle the argument.

This guide covers how to read pot codes on Fender guitars and basses from the 1950s through the 1980s. You will learn the manufacturer codes for CTS, Stackpole, and CRL, the year-and-week dating convention, where to find the codes, and why the pot date is usually a little earlier than the guitar's final assembly date.

If you are trying to place a guitar in the right decade, start with the free Fender serial number decoder. Then open the control cavity and let the pots tell you the rest.

What Are Pot Codes and Why Do They Matter?

A potentiometer, or pot, is the variable resistor behind every volume and tone knob. It is stamped with a code that identifies the maker and the week it rolled off the production line.

The code matters because pots were installed at the factory. A pot dated 1965 almost certainly came from a guitar assembled in 1965 or 1966, not a 1975 reissue. Collectors use pot codes to confirm originality, detect replaced electronics, and cross-check claims when a serial number or neck date looks suspicious.

How to Read a Fender Pot Code

Most vintage Fender pots use a six-digit code in this order:

Manufacturer code (3 digits) + Year (2 digits) + Week (2 digits)

For example, a pot stamped 137-6612 breaks down as:

• 137 = CTS (manufacturer code)
• 66 = 1966 (year)
• 12 = week 12 (approximately mid-March)

A pot stamped 304-5908 breaks down as:

• 304 = Stackpole
• 59 = 1959
• 08 = week 8 (late February)

The format stayed stable for decades. Once you can split the code into those three pieces, you can date almost any pot you find in a Fender.

The Manufacturer Codes You Will See

These are the most common manufacturer codes in Fender guitars and basses:

Code	Manufacturer	Common Fender Era
137	CTS (Chicago Telephone Supply)	Mid-1960s through 1980s
304	Stackpole	1950s through early 1960s
105	CRL (Centralab)	Some 1950s and early 1960s instruments
450	CTS/Sola (rare)	Occasional 1960s and 1970s
618	Bourns	Occasional 1970s imports and reissues

CTS and Stackpole are the big two. If you see 137, you are almost certainly looking at a CTS pot. If you see 304, it is Stackpole. CRL pots appear on some early Fenders, often with a 105 code.

Year and Week Format

The year is almost always the last two digits of the calendar year. A code ending in 57 means 1957, 72 means 1972, and 84 means 1984. The week is a number from 01 to 52 or 53. Week 01 is the first week of January, and week 52 is late December.

Some late-1950s and early-1960s Stackpole pots use a slightly different layout with the manufacturer code and date reversed or separated by a dash. If the numbers do not read cleanly left to right, try reading them right to left. The six digits still resolve into manufacturer, year, and week.

Where to Find Pot Codes on a Fender

Pot codes are stamped on the side or back of the potentiometer can. To see them, you usually need to remove the control plate or pickguard.

Stratocaster

On a Stratocaster, remove the pickguard screws and lift it gently. The three pots sit in a row on the pickguard underside. Tilt the assembly toward the neck and look at the side of each pot can.

Telecaster

On a Telecaster, the pots are mounted to a metal control plate on the back of the guitar. Remove the control plate and flip it over. The volume and tone pots are easy to read once exposed.

Jaguar and Jazzmaster

Jaguar and Jazzmaster controls are mounted on a chrome plate under the pickguard. Remove the pickguard, and you will see the rhythm and lead circuit pots clustered together. A flashlight helps because the pots sit close to the body.

Precision Bass and Jazz Bass

Fender basses use the same pot codes as guitars. On a Precision Bass, the two knobs mount to a small metal plate. On a Jazz Bass, three knobs mount to a similar plate. Remove the plate and read the stamps on the underside.

Tips for Reading Faint Stamps

Pot stamps are small, and decades of solder flux and dust can hide them. Angle a flashlight across the can so the shadows highlight the stamp. A phone photo with the flash off often captures the detail better than the naked eye.

CTS Pot Codes on Fender Guitars

CTS became the dominant pot supplier for Fender starting in the mid-1960s. If your guitar has 137-coded pots, you are almost certainly looking at a CBS-era or later instrument.

Reading a CTS Code

A typical CTS pot in a 1966 Stratocaster reads 137-6618: CTS, 1966, week 18. A 1973 Telecaster might read 137-7327: CTS, 1973, week 27. The consistent format makes CTS pots the easiest to read.

When Fender Switched to CTS

Fender used Stackpole and CRL pots through the 1950s and early 1960s. By 1964 and 1965, CTS pots were becoming standard in most USA models. By 1966, a Stratocaster or Telecaster with original electronics almost always had CTS 137 pots. A guitar claimed to be a 1962 Stratocaster but fitted with 137-coded CTS pots has been rewired or has replacement electronics.

Stackpole Pot Codes on Fender Guitars

Stackpole supplied many of Fender's pots through the 1950s and early 1960s. Pre-CBS Strats, Teles, Jaguars, Jazzmasters, and Precision Basses often carry 304-coded Stackpole pots.

Reading a Stackpole Code

A 1959 Stratocaster pot might read 304-5932: Stackpole, 1959, week 32. A 1961 Jazzmaster might read 304-6112: Stackpole, 1961, week 12. The format mirrors the CTS layout, so the same decoding rules apply.

Stackpole vs CTS on Vintage Fenders

Stackpole pots are common on pre-CBS instruments, while CTS pots dominate CBS-era and later guitars. Fender used existing stock during transitions, so a few months of overlap is normal. If the pot date is more than a year away from the claimed guitar date, it is worth asking why.

CRL Pot Codes and Other Manufacturers

CRL pots appear less frequently than CTS or Stackpole. The code 105 is associated with CRL/Centralab production, and some early 1950s Fenders used CRL pots alongside Stackpole hardware. Other codes you might encounter include Bourns (618) on some 1970s imports and reissues. When the manufacturer code does not match a common Fender supplier, treat it as a sign that the electronics may have been replaced.

Why Pot Dates Are Usually Earlier Than the Guitar Date

Pots were manufactured in batches and then sat in Fender's parts inventory before being soldered into a guitar. A pot dated week 10 of 1965 might not be installed until week 30 of 1965, or even early 1966. That gap is completely normal.

Most collectors accept a pot date that falls within about 12 months before the guitar's assembly date. A gap of six months is typical. A gap of two years is unusual and should be explained by documented repairs, factory practices, or clear provenance.

This lag also works the other way. A guitar claimed to be a 1959 Stratocaster but fitted with 1966 CTS pots cannot be original. Either the electronics were replaced, or the guitar is not a 1959. Pot codes are therefore a powerful reality check against inflated seller claims.

Using Pot Codes to Authenticate a Fender

Pot codes are one of the strongest pieces of evidence inside a vintage guitar. Use them alongside the serial number, neck date, and hardware.

Cross-Check the Serial Number

Run the serial number through the Fender serial number decoder. A 1965 serial with 1964 or 1965 pots is consistent. A 1965 serial with 1978 pots is not.

Cross-Check the Neck Date

The neck date and pot dates should cluster within about a year of each other. If the neck is dated 1963 and the pots are dated 1967, the neck is probably not original. See our Fender neck date vs serial number guide for more.

Look for Signs of Resoldering

Original solder joints are slightly dull, with a small fillet where the capacitor lead meets the pot lug. Shiny modern solder or disturbed ground wires suggest someone has been inside the control cavity.

Check the Capacitors

Yellow Astron, blue molded, and ceramic disc caps were used in different eras. A matched set of correct-era pots and caps is stronger evidence than pots alone. If the caps are modern but the pots are vintage, the pots may have been harvested from another guitar.

Pot Codes by Fender Era

The pots you find depend heavily on the era of the guitar. Here is a quick reference for what to expect.

Pre-CBS Era (1954–1964)

Pre-CBS Fenders usually have Stackpole 304 pots, especially through the late 1950s and into the early 1960s. Some early guitars also carry CRL 105 pots. By 1964, CTS 137 pots were beginning to appear, but Stackpole remained common.

Typical codes for a 1962 Stratocaster:

• Manufacturer: Stackpole (304)
• Year: 62
• Week: any week in 1962 or very late 1961

CBS Era (1965–1985)

CBS-era Fenders almost always have CTS 137 pots. The transition happened around 1964–1965. By 1966, CTS was the standard supplier for USA Strats, Teles, Jaguars, Jazzmasters, and basses.

Typical codes for a 1972 Telecaster:

• Manufacturer: CTS (137)
• Year: 72
• Week: any week in 1972 or late 1971

1980s Fenders

CTS continued as the dominant supplier through the 1980s. Some Japanese-made Fenders used different manufacturers, including Bourns or Japanese suppliers with non-EIA codes. If you are dating a Japanese Fender from the 1980s, the pot codes may not follow the same rules as USA instruments. Our Fender E-series serial numbers guide covers those guitars in detail.

Common Pot Code Misreads and Mistakes

Even experienced collectors misread pot codes now and then. Here are the most common pitfalls.

Reading the Code Backward

Stackpole pots can be stamped with the manufacturer code and date in either direction. If 304-5932 does not make sense, try 5932-304. The manufacturer code is always three digits, so look for the 137, 304, or 105 grouping.

Confusing Resistance with Date

Pots also show values like 250k, 500k, or 1M. These are resistance ratings, not date codes. The date code is the six- or seven-digit stamped number, usually smaller than the resistance marking.

Assuming a Replaced Pot Means a Fake Guitar

A single replaced pot does not make a guitar fake. Volume pots wear out, and many vintage Fenders have had one pot swapped during a repair. One modern pot in an otherwise original 1966 Stratocaster is a repair, not a fraud.

Ignoring the Capacitors and Wiring

Pot codes are one clue among many. Always look at the caps, switches, jack, wiring color, and solder joints. A correct pot date with modern caps and fresh solder is a warning sign that the electronics have been rebuilt.

What Pot Codes Reveal About Value

Originality drives vintage Fender prices, and original electronics are a big part of that equation. A guitar with all four original pots, original caps, and untouched solder can command a premium over a similar guitar with replaced electronics.

All-Original Electronics

Collectors pay more for guitars that still have their factory pots. An all-original 1960s Stratocaster can outsell a functionally identical rewired example by 15 to 30 percent.

One or Two Replaced Pots

A player-grade vintage Fender with one replaced pot is still desirable. It should be sold as a player guitar, with the price reflecting the modification.

Fully Rewired Guitars

A vintage Fender with a completely rewired control cavity and modern pots is worth less to collectors, even if the wood and neck are original. Use the Guitar Price Estimate tool to compare market ranges.

Internal Links and Next Steps

• Fender Serial Number Lookup — Decode any Fender or Squier serial instantly
• Fender Authenticity Check — Free red-flag checklist for suspicious guitars
• Fender Neck Date vs Serial Number — How to reconcile neck stamps with serial numbers
• Pre-CBS Fender Serial Numbers — 1954–1964 dating and value guide
• CBS-Era Fender Serial Numbers — 1965–1985 dating and value guide
• Vintage Stratocaster Identification — Visual markers by era
• Vintage Telecaster Identification — Visual markers by era
• Fender Stratocaster Value Guide — Market values by year and condition
• Fender Telecaster Value Guide — Market values by year and condition
• Fender Setup Guide — Printable factory specs by model and era

FAQ

What are Fender pot codes?

Fender pot codes are stamped numbers on the potentiometers inside a Fender guitar or bass. They identify the manufacturer and the week the pot was made, which helps date the instrument and confirm originality.

How do you read a Fender pot code?

A standard Fender pot code has six digits: manufacturer code (3 digits), year (2 digits), and week (2 digits). For example, 137-6612 means CTS, 1966, week 12.

What does 137 mean on a Fender pot?

The code 137 is the Electronics Industries Alliance manufacturer code for CTS (Chicago Telephone Supply). CTS supplied most Fender pots from the mid-1960s through the 1980s.

What does 304 mean on a Fender pot?

The code 304 is the manufacturer code for Stackpole. Stackpole supplied many Fender pots in the 1950s and early 1960s, especially on pre-CBS instruments.

Can you date a Fender by its pots?

Yes, within a window. Pot dates usually fall a few weeks to a few months before the guitar was assembled. A pot dated 1966 is strong evidence that the guitar was built in 1966 or early 1967.

Should pot codes match the serial number year exactly?

Not necessarily. Pots were made in batches and could sit in inventory before installation. A pot date within about 12 months of the guitar's assembly date is usually acceptable. Larger gaps suggest replaced parts or a mismatch.

What if a Fender has pots from different years?

Guitars sometimes left the factory with pots from slightly different batches, so a small spread is normal. If one pot is several years newer than the others, it was probably replaced during a repair.

Where are the pot codes on a Stratocaster?

On a Stratocaster, the pot codes are stamped on the sides of the three potentiometers mounted to the underside of the pickguard. Remove the pickguard to read them.

Do Japanese Fenders use the same pot codes?

Not always. Japanese-made Fenders from the 1980s sometimes use pots with non-EIA manufacturer codes. The CTS/Stackpole/CRL system applies most reliably to USA-made Fenders.

Do pot codes prove a Fender is original?

Pot codes are strong evidence but not proof on their own. They should be checked alongside the serial number, neck date, hardware, capacitors, and solder joints. For a structured authenticity review, use the Fender authenticity checker.

Conclusion

Fender pot codes are one of the best tools for dating and authenticating a vintage guitar. The small stamped numbers on the side of each pot tell you who made it and when, usually within a week or two.

Start with the Fender serial number decoder to get the broad year and factory. Then remove the pickguard or control plate and read the pot codes. Compare them to the neck date, hardware, and capacitors. Allow a few months of normal production lag, but question gaps of a year or more.

Once the guitar is dated and verified, make it play its best with the Fender Setup Guide. It puts factory-correct action, relief, intonation, and pickup height specs for your exact year and model on one printable page.