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:
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|
|1956 - 1968|
|1969 - 1991|
|1991 - 2014|
|2015 - 2020
|A - Jan||A - 1944||A - 1956||B - 1969||A - 1991||A - 2015ah|
|B - Feb||B - 1945||B - 1957||C - 1970||B - 1992||B - 2016ah|
|C - Mar||C - 1946||C - 1958||D - 1971||C - 1993||C - 2017ah|
|D - Apr||D - 1947||D - 1959||E - 1972||D - 1994a||D - 2018ah|
|E - May||E - 1948||E - 1960||F - 1973||E - 1995a||E - 2019ah|
|F - Jun||F - 1949||F - 1961||G - 1974||F - 1996a||F - 2020ah|
|G - Jul||G - 1950||G - 1962||H - 1975||G - 1997a|
|H - Aug||H - 1951||H - 1963||I/J - 1976||H - 1998a|
|I/J - Sep||I/J - 1952||I/J - 1964||K - 1977||I/J - 1999a|
|K - Oct||K - 1953||K - 1965||L - 1978||K - 2000a|
|L - Nov||L - 1954||L - 1966||M - 1979||L - 2001**ah|
|M - Dec||M - 1955||M - 1967||N - 1980||M - 2002ah|
|A - 1968*||P - 1981||N - 2003ah|
|Stamp locations:||Q - 1982||P - 2004ah|
|Green = chassis rim||R - 1983||Q - 2005ah|
|Yellow = front gasket||S - 1984||R - 2006ah|
|Blue = chassis leg||T - 1985||S - 2007ah|
|Purple = magnet sticker||U - 1986||T - 2008ah|
|V - 1987||U - 2009ah|
|Speaker models:||W - 1988||V - 2010ah|
|a = Modern alnico models||X - 1989||W - 2011ah|
|h = Heritage models & some UK made greenbacks||Y - 1990||X - 2012ah|
|Z - 1991||Y - 2013ah|
|*Transition from front gasket to chassis leg = April 1968||Z - 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:
- On a magnet sticker = early 2001 to present. Note – if the date code is printed directly onto the magnet without a sticker, it is likely a chassis leg period stamp on a black speaker.
- On the chassis leg = April 1968 to early 2001 (& heritage series 2005 to present, & some UK made greenbacks 2001 to 2005).
- On the front gasket = 1952 to March 1968 (& modern alnicos 1994 to present).
- On the chassis rim = 1944 to 1951. Or it is a chassis leg stamp printed in the wrong place, these are most common through mid 1968.
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.
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 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 Celestion’s website to use the stamp format to date your speakers. I do not recommend this method. The stamp formats are not very consistent and this confuses a lot of people:
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
Date codes are usually printed on the outer rim of the chassis and consist of 4 digits only.
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
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
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
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
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
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:
mid 1976 to late 1985
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.
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
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
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
From around April 1990, the ‘T’ prefix is usually included with the model number.
Black frames / Sidewinder models
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
Date codes are printed on the front gasket and may include the model number and inspection number.
Standard production models – early 2001 to present
Date codes are printed on a magnet sticker and go back to the simple 4 digit system.