Celestion Date Codes

Celestion Date Codes

Celestion date codes are located on the front gasket, the chassis, or a magnet sticker.

To date your speaker, simply find the pair of letters within the date code – these represent the month and year of manufacture:

Month & Year Stamp

Then use the reference table below to decipher them. For 12″ speaker models, use the stamp location colour codes to guide you.

If you need more help, scroll further down the page for a more detailed explanation.

Celestion Date Codes Chart

MONTH

1944 - 1955
[DDMY]
1956 - 1968
[DDMY]
1969 - 1991
[MYDD]
1991 - 2014
[DDMY]
2015 - 2020
[MYDD]
A - JanA - 1944A - 1956B - 1969A - 1991A - 2015ah
B - FebB - 1945B - 1957C - 1970B - 1992B - 2016ah
C - MarC - 1946C - 1958D - 1971C - 1993C - 2017ah
D - AprD - 1947D - 1959E - 1972D - 1994aD - 2018ah
E - MayE - 1948E - 1960F - 1973E - 1995aE - 2019ah
F - JunF - 1949F - 1961G - 1974F - 1996aF - 2020ah
G - JulG - 1950G - 1962H - 1975G - 1997a
H - AugH - 1951H - 1963I/J - 1976H - 1998a
I/J - SepI/J - 1952I/J - 1964K - 1977I/J - 1999a
K - OctK - 1953K - 1965L - 1978K - 2000a
L - NovL - 1954L - 1966M - 1979L - 2001**ah
M - DecM - 1955M - 1967N - 1980M - 2002ah
A - 1968*P - 1981N - 2003ah
Stamp locations:Q - 1982P - 2004ah
Green = chassis rimR - 1983Q - 2005ah
Yellow = front gasketS - 1984R - 2006ah
Blue = chassis legT - 1985S - 2007ah
Purple = magnet stickerU - 1986T - 2008ah
V - 1987U - 2009ah
Speaker models:W - 1988V - 2010ah
a = Modern alnico modelsX - 1989W - 2011ah
h = Heritage models & some UK made greenbacksY - 1990X - 2012ah
Z - 1991Y - 2013ah
*Transition from front gasket to chassis leg = April 1968Z - 2014ah
**Transition from chassis leg to magnet sticker = early 2001

Note – Ceramic guitar speakers (greenbacks) first appeared around 1964 / 1965, so it is highly unlikely you will find any earlier than this. Before 1965 guitarists were mainly using the alnico G12 models.

How To Date Your Speaker

Step 1 – Check The Stamp Location (12″ speakers only)

The location of the date code tells us the most likely date range the speaker was made:

Date Code Locations

These stamp locations hold true for most 12″ speaker models, other sizes of speaker may be different. 15″ and 18″ speakers tend to be on the outer rim.

Step 2 – Decipher The Date Code

All Celestion date codes contain a pair of letters representing the month and year the speaker was made. In most cases the first letter represents the month, and the second letter represents the year.

Month & Year Stamp

To date your speaker, simply find the pair of letters in your date code and use the chart at the top of the page to decipher them.

A number directly next to the pair of letters, if present, is the day of the month. So ‘GB17’ on the photo above = 17th July 1969 (ignore the ‘Y’).

It’s that simple!

Just be careful of date codes printed in reverse (year then month), these are generally rare but are fairly common on mid 1970’s creambacks.

More example date codes are shown further down the page. Use them to compare against your own.

If you are struggling to date an old greenback speaker using the Celestion date codes chart above then my blog post how to date vintage greenback speakers should help you further.




What About The Stamp Format?

You might have read on the Celestion website to use the stamp format to date your speakers.

The stamp format can be useful for verification. For example a ‘DB’ date code on the frame leg would be translated as 1969 if it was in the format MYDD, or 1992 if it was in the format DDMY.

However, I do not recommend using the stamp formats as the main basis for dating your speakers. The problem is, Celestion were not very consistent with them and this confuses a lot of people:

Stamp Formats
Both of these speakers were made Nov 1969.

I have included the stamp formats in the year column headers on the chart if you want to use them.

Other Markings

other markings

An extra single letter is apparently just an ‘inspection letter’ and can be ignored. For dating purposes it is useful to know these are only usually present on speakers made between 1969 to 1976. From 1986 onwards a two digit number is normally used instead.

The code beginning with the letter ‘T’ is the model number of the speaker, for example ‘T1281’ represents a 55Hz 16 Ohm G12H.

The small circular stamp with ‘insp’ text or a letter ‘P’ inside it, is a quality control stamp. It is an important stamp to look for to authenticate old ‘pre-rola’ speakers.




Example Celestion date codes through the years

1944 to 1951

01MG = 1st Dec 1950
01MG = 1st Dec 1950

Date codes are usually printed on the outer rim of the chassis and consist of 4 digits only.

Note: You might have read on Celestion’s website that the letter M was excluded from the month codes until 1963. That is incorrect, as is evident here.

Celestion month codes always went from A to M, skipping the letter ‘I’.

If you ever find a letter ‘I’ in your date codes it is just a typo and should be a letter ‘J’. See next photo for an example of that.

1952 to Spring 1966

08AI = 8th Jan 1964
08AI = 8th Jan 1964

Date codes are usually stamped on the front gasket of the speaker. Notice the large font size and white manilla paper gasket. A leading zero is used for single digit numbers.

The font size is reduced from around mid 1965 onwards.

Spring 1966 to March 1968

07ML = 7th Dec 1966
07ML = 7th Dec 1966

The gasket material is made from cork with a thin paper overlay and is made up of 4 separate pieces. The date code is still on the front gasket but with a smaller font size.

Fake date stamps

29HM = Supposedly 20th Aug 1967
29HM = Supposedly 29th Aug 1967

Any greenback speakers with pre-April 1968 date codes printed on the chassis leg are likely to be fakes. Genuine stamps would be on the front gasket (as in the previous photo above) until April 1968.

April 1968 to December 1968

26JA = 26th Sept 1968
26JA = 26th Sept 1968

Date codes are printed horizontally on the frame. The faint ink can sometimes make them difficult to read. Occasionally they might be printed on the outer rim.

Note: The typical stamp format for 1968 is DDMY, not MYDD as stated on Celestion’s website.

1969 to mid 1976

DC1 = 1st April 1970
DC1 = 1st April 1970

Date codes are printed vertically on the frame. An additional inspection letter is usually included (except Aug 73 to Jun 74), these can be ignored for dating purposes.

Leading zeros are usually omitted from the day of the month, eg ‘6’ instead of ’06’.

From around Dec 1971 to Sept 1972 the day of the month is usually omitted:

JE = Sept 1972
JE = Sept 1972

mid 1976 to late 1985

AM9 = 9th Jan 1979
AM9 = 9th Jan 1979

From around June 1976 the inspection letter is no longer included.

The circular quality control stamp changes appearance through the years: From roughly March 1978 to mid 1980 – usually a large letter ‘P’ or ‘Q’. From around mid 1980 to late 1985 – usually an “insp number” stamp with no circular border.

FS27 = 27th June 1984
FS27 = 27th June 1984

From about mid 1983 to 1986 the T model number is rarely stamped on the frame leg because it is shown on the speaker label.

1986 to late 1987

EU22 = 22nd May 1986
EU22 = 22nd May 1986

From around Jan 1986 onwards the ‘insp’ stamp is no longer used and the two digit inspection number is appended to the end of the date code instead. These inspection numbers can be ignored for dating purposes.

Late 1987 to early 1990

MV1 = 1st Dec 1987
MV1 = 1st Dec 1987

From around Dec 1987 to April 1990 – the date code, speaker model, and inspection number are joined together in one continuous line. The letter ‘T’ prefix is usually omitted from the speaker model.

1990 to mid 2001, & ‘Heritage’ models, & UK made greenbacks 2001 to 2005

17KF = 17th Oct 1996
17KF = 17th Oct 1996

From around April 1990, the ‘T’ prefix is usually included with the model number.

From 1991 onwards, leading zeros are usually included with the day of the month, eg ’08’ instead of ‘8’.

Black frames / Sidewinder models

LY02 = 2nd Nov 1990
LY02 = 2nd Nov 1990

Due to the black coloured frame, the date stamp is printed on the magnet instead of the chassis leg.

Alnico models – 1994 to present day

20BY = 20th Feb 2013
20BY = 20th Feb 2013

Date codes are printed on the front gasket and may include the model number and inspection number.

Standard production models – early 2001 to present

27FN = 27th June 2003
27FN = 27th June 2003

Date codes are printed on a magnet sticker and go back to the simple 4 digit system.

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