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.

33 Comments

  1. February 27, 2020 / 6:27 pm

    Does the code N 9BK make any sense? My amp guru says they must have transposed the B and the K at the factory but that seems a bit farfetched. It has the cone code of 23 102 014 and is a T1281 with no magnet cover. Two of the speakers in the cabinet have this date code. The other two are 029 JB

  2. Ed Amantia
    March 20, 2020 / 12:13 pm

    Hey there, thanks for such a fantastic and informative site!… There is something unusual about a ‘69 Celestion I have. It is a T1281 G12H. The first thing that is unusual is it happens to have the exact same date (GB17Y) of the one above that you have on your site showing what the date code means! Weird… But the main reason I’m contacting you is this should obviously have an 014 cone yet it has an 003 cone which obviously is not correct for a T1281?… Everything about the speaker looks correct, the spider, the cone, the frame etc. Have you ever seen this situation where a T1281 has a 003 cone? Another strange thing is the original pre-Rola solder tabs are gone although this may have just been a repair that somebody put more modern tabs on it. Thanks!
    Best, Ed

    Sent from my iPhone

    • Brian Harding
      Author
      March 20, 2020 / 4:52 pm

      Hi Ed, good to hear from you. Yes it is definitely unusual to find a speaker with the wrong cone fitted like that. I have seen a handful of similar examples such as T1511 fitted with 003 cone, and T1221 fitted with ‘4’ cone. It is unusual, but does seem some left the factory with the wrong cones.

      The solder terminals breaking off is a fairly common problem on pre-rola’s, got to treat them with care. Repairing them is difficult when they have broken off. There are some good and bad amateur repairs out there!

      Hope that helps, Brian.

  3. Nikolaj Nisson
    June 20, 2020 / 8:06 pm

    Hey! Great page!

    I got 4x greenbacks g12m25 with basscones, and the seller told me they were made 1969.
    Stamps on leg say : V(or Y) 22KB and T1511. So it seems its backwards? B = 1969?

    The white stamps on cones read: 29 102 014.

    Are they really from 1969? The backward stamp makes me confused now.

    Cheers!

    • Brian Harding
      Author
      June 20, 2020 / 10:52 pm

      Hi Nikolaj, thanks, yes that sounds like a 1969 stamp to me, and correct cone code for the period. It is fairly common to find them printed back to front in late 69. This page explains further. Those should be very nice sounding speakers too!

      Hope that helps,

      Brian.

  4. Lachlan
    August 8, 2020 / 6:10 am

    Hi guys, just curious, when did Celestion start stamping MADE IN ENGLAND into the speaker rim?

    Thanks in advance.

    • Brian Harding
      Author
      August 8, 2020 / 10:36 am

      Hi Lachlan, good question! I have just had a look over my photos and the ‘made in england’ stamp on the rim seems to first appear on speakers with an April 1966 date code (DL). At least I can’t find any examples earlier than this, they could exist, but not in my photo collection. So we both learned something!

      Brian.

  5. gary
    October 25, 2020 / 8:59 am

    i think i have 1993 speakers, code reads 0ec t 3760 11 , any help?

    • Brian Harding
      Author
      October 25, 2020 / 11:36 am

      Hi Gary, yes the first digit is missing, but the ‘ec’ part is the month and year. So that would be May 1993. T3760 = G12T-75. ’11’ is the inspection number. The layout is also correct for that period, so that verifies it.

      Hope that helps,

      Brian.

  6. gary
    October 25, 2020 / 3:58 pm

    thats why i was confused, all 4 speakers have the same code, but only 1 digit not 2, thx for verifying this for me. gary

  7. William
    November 26, 2020 / 10:14 pm

    I’ve two speakers t 15 17 cc25x
    T15 17 fc 24 r numbers on the cone are 52-102-003
    16-102-003 any idea what yr they are from ? Or what they came in ?

    • Brian Harding
      Author
      November 26, 2020 / 10:50 pm

      Hi William. Those are model T1517, a G12S model speaker. I know they were used by Selmer, possibly other brands too. Have you got any photos you can send me please? info@bygonetones.com There is some more info about those on my greenbacks page here: https://www.bygonetones.com/vintage-celestion-greenback-models.html#T1417 FC24 and CC25 are the date codes June 1970 and March 1970. Those are “pre-rola” so fairly collectable but they don’t tend to bring the same prices as the G12M and G12H speakers. If you are selling those I might be interested depending on condition, send me an email with some photos if you can. The ‘102 003’ stamp on the cones is the pulsonic code for a 75Hz cone. More info on that on my cones page here: https://www.bygonetones.com/vintage-celestion-guitar-speaker-cones.html

      Hope that helps, Brian.

  8. Matt
    January 5, 2021 / 8:55 pm

    I have a G12M with gray plastic, Rola Celestion LTD – Ipswich/ Suffolk label, with date code MF30Z, and an underlined 3 on the cone. Is this a December 1973 with Pulsonic cone? Any thoughts on it’s value?

    • Brian Harding
      Author
      January 6, 2021 / 7:14 pm

      Hi Matt, yes thats Dec 73, pulsonic cone.

      The value of any vintage Celestion speaker really depends on its condition and how good it sounds, not just on “what it is”.

      There are loads of potential issues a speaker can have that will have a negative impact on it’s value, but the most common ones are coil rub and failing glue at the spider support. So to value your speakers properly you should give them a full health check first. My page here should help with that:

      https://www.bygonetones.com/how-to-test-a-vintage-celestion-greenback-speaker.html

      For an indication on how much people are asking for them you can check sold prices on reverb.com here:

      https://reverb.grsm.io/Celestion-1973-Sold-Listings

      Hope that helps, Brian.

  9. Marc
    January 13, 2021 / 6:05 am

    Hello, thank you very much for the very informative side, Brian!
    I have just seen a Blue Celestion speakers with the date code 20 FM with RIC cones and was asking myself if they could be from 1967 or 1961? Would you be able to help? Thank you very much. Best regards Marc

    • Brian Harding
      Author
      January 13, 2021 / 3:53 pm

      Hi Marc, likely the date code is back to front, so 20th Dec 1961. 67 is very unlikely for a vox blue. They were only blue for a few years – 1960 to 1964, after that they were painted silver instead. The RIC cones also were only standard from about 1960 to mid 1962 on the blue, the H1777 / 003 pulsonic cones were standard from around mid 62 onwards.

      regards, Brian.

      • Marc
        January 13, 2021 / 6:38 pm

        Thanks Brian, for the very helpful information!

  10. Tibor
    January 14, 2021 / 4:08 pm

    Brian,

    I am looking at a pair of 1982 T3054 speakers with apparently no insp stamp. Is that regular?
    Thanks

    • Brian Harding
      Author
      January 16, 2021 / 6:47 pm

      Hi Tibor, I would expect to see an inspection number on a 1982 speaker yes. However they do sometimes wear off or get cleaned off by previous owners. It is not something I would worry about on a G12-65. It wont be a fake or anything like that.

      Hope that helps, Brian.

  11. John
    January 25, 2021 / 2:43 pm

    I have a Celestion Blue with 03MCT4427B on the front gasket.
    It would date this ‘modern’ AlNiCo back to 03 december 1993.
    Throughout your awesome website 1994 is used as the first year for these.
    Also, do you happen to know what the “B”-suffix stands for? I’ve seen “A” and “B” added to the T-number on several models.

    • Brian Harding
      Author
      January 25, 2021 / 8:08 pm

      Hi John, if you’re absolutely sure about the letter C in the date code then that would most likely put it at Dec 2017. Celestion were not always consistent with their stamp format (DDMY or MYDD) so it is not always a reliable way to date speakers.

      I do know what the letter A and B stand for at the end of the T number, however I have been asked by Celestion not to publish it on the website because it is for their own internal use. However I can tell you they only started adding those extra letters around 2005, or 2003 at the very earliest, due to new manufacturing laws. So, any speakers made before then will not have the extra A or B on the end of the code. This is how we can say your speaker is likely not from 1993.

      Fwiw I think the first Vox Blue speakers to be introduced in 94 were likely models T530 and T727, because they were initially made for the Vox AC30 reissues. From what I understand, model T4427 is a slightly different spec to the Vox version. I’m not sure exactly when they first started making that model but likely would have come along a bit later than the first run of Vox speakers. You might want to email drdecibel for clarification on that – drdecibel@Celestion.com

      Hope that helps,

      Brian

      • John
        January 28, 2021 / 9:33 pm

        Hi Brian,

        Thank you for the detailed information. All very helpful.
        Much appreciated!

        Regards,
        John

  12. Max
    February 2, 2021 / 2:37 pm

    I’ve got two T1088 silver G12 8 Ohm that have much larger centre cone caps, about 9cm diameter. The cone only has a mark of “444”, so I just wondered if you know what they are or anything about them.

    Thanks
    Max

    • Brian Harding
      Author
      February 2, 2021 / 7:38 pm

      Hi Max, sounds like a recone to me. Probably a late 70’s or 80’s Mueller cone. If you email me some photos I will have a look. info@bygonetones.com

      regards, Brian.

  13. Jonny B
    February 22, 2021 / 12:27 pm

    Very helpful information to date speakers. I’ve got a yellow G12/50 with the date code GK21. using your chart I’ve made that July 21st 1977, hope that’s right!

    • Brian Harding
      Author
      February 22, 2021 / 4:51 pm

      Hi, thanks. That sounds about right to me. Those yellow frame G12/50’s do tend to be mid to late 70’s speakers.

      Brian.

      • Jonny B
        February 23, 2021 / 6:46 pm

        Brian thanks for that. Also the cone has 1975 printed in white, – would that be manufacture date?
        By the way I’m selling it on eBay at present if you want to have a look. Cheers.

        • Brian Harding
          Author
          February 23, 2021 / 7:23 pm

          Hi, the ‘1975’ is just the specification for the cone, not the date. It’s just coindidence it looks like an actual date.

          Brian.

  14. John Oswald
    April 3, 2021 / 6:44 am

    I just purchased a Marshall 1960BC. G12M speakers, the stamp on all 4 is R2BK T1221/ 04 Can you please help decode this?
    Many thanks

    • Brian Harding
      Author
      April 3, 2021 / 11:12 am

      Hi John, yes if you look at the example photos, that date code is in the style normally seen from 1990 to mid 2001. The BK in the code will be Feb 2000. You are probably reading the first ‘R’ in the code incorrectly. It should be a number representing the day of the month, so can only be either a 0, 1 or 2. The ink is probably a bit smudged making it look like something else. T1221 is the model of the speaker, and 04 is an inspection number.

      regards, Brian.

  15. Alex
    April 16, 2021 / 10:35 am

    Hi. I have an AC30 and one speaker has the cone code 1 H1777 (The ‘H’ on this one doesn’t really look like an ‘H’, it’s more of a blob of ink. Would I be correct to assume it was smudged during application, or could it be something else?)

    The other is 52 H1777. Do the numbers represent the week? If so, do the cones not mark the year?

    Oddly the tinsel wire on one of them is routed from the cone and out of the basket, and joins to the terminal externally. The other has it’s wires routed normally and you can’t see them just by looking at the speaker from the back, if you know what I mean. Has the other one been repaired at some point or could this have happened at the factory?

    Many thanks for this great resource!

    • Brian Harding
      Author
      April 19, 2021 / 2:35 pm

      Hi Alex, can you send me some photos of those? info@bygonetones.com

      The number prefix before the H1777 is supposedly meant to represent the week of the year that the cone was made, not the speaker, however you can find them a lot higher than 52 on some speakers, so that might not be true. Ink smudges and typos are not too unusual.

      As for the solder terminal, they changed design in early 66. The earlier ones are on the frame, and the later ones are on card between the chassis legs. You can see examples of that here: https://www.voxac100.org.uk/celestion_silvers.htm

      I would have to see photos of them to say if they have been repaired or not.

      Hope that helps, Brian.

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