Celestion Date Codes

Celestion Date Codes

How To Date Your Speaker

All Celestion date codes contain a pair of letters. These represent the month and year of manufacture.

Celestion date code

A number directly next to the pair of letters, if present, is the day of the month.

To date your speaker, simply use the reference table below to decipher the pair of letters.

In the example above, GB17 = 17th July 1969. The additional letter ‘Y’ can be ignored.

Date Stamp Locations

For 12″ speakers, the location of the date stamp can guide us to the right time period. These are colour coded on the chart below.

Date Code Locations

The date stamp location for 15″ and 18″ speakers, tends to be on the outer rim of the chassis.

Celestion Date Codes Chart


1944 - 1955
1956 - 1968
1969 - 1991
1991 - 2014
2015 - 2020
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 - 1997aG - 2021ah
H - AugH - 1951H - 1963I/J - 1976H - 1998aH - 2022ah
I/J - SepI/J - 1952I/J - 1964K - 1977I/J - 1999aI/J - 2023ah
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.

’23KH’ on the chassis rim, would be 23rd October 1951
’15BH’ on the front gasket, would be 15th February 1963
‘DC18 N’ on the chassis leg, would be 18th April 1970. Ignore the additional inspection letter.
‘HE V’ on the chassis leg, would be August 1972. Ignore the additional inspection letter.
’10HG’ on the chassis leg, would be 10th August 1997
’27CS’ on a magnet sticker, would be 27th March 2007

Please also use the example photos at the bottom of the page for comparison. These can be very helpful 😉

About The ‘Stamp Format’

You might have read on other websites and books to use the stamp format to date Celestion speakers.

Generally speaking, there was an alternating cycle of Day-Month-Year (DDMY) then Month-Year-Day (MYDD). These are included at the top of the chart for reference and can be helpful for guidance.

However, just be careful using this method. There are quite a few speakers out there that do not comply, and this tends to confuse people.

Celestion Date Code Stamp Formats
Both of these speakers were made Nov 1969.

Oddities and typos

1) Sometimes the month and year codes were printed back to front by mistake. eg HA16 instead of AH16 for 16th Jan 1975.

16th Jan 1975, not 16th Aug 1968!
16th Jan 1975, not 16th Aug 1968!

A particular hotspot for this typo is late 1974 into early 1975. The way to spot them is by looking at the other period features of the speaker. For example, the cream coloured magnet covers tend to be from 74 or 75, rather than 1968.

I have written a more in-depth article on how to identify these typos here – back to front celestion date codes.

2) Through mid 1968 you might find the codes printed on the outer rim of the chassis instead of on the chassis leg.

09DA = 9th April 1968
09DA = 9th April 1968

3) Some speakers, such as the sidewinder series, may have their date stamps printed on the outer edge of the ceramic magnet instead of the chassis leg. Probably because the frame leg is painted black.

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

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 when authenticating 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.

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 Celestion date codes

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.

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

Celestion date codes 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

Celestion date codes 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’.

Alnico models – 1994 to present day

Celestion date codes 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.


  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

      • Ku
        October 5, 2022 / 10:23 pm

        Hello Brain,
        I feel even more confused than before I started trying to date my cab. The Celestians I have are G12T-75’s and the code is somewhat confusing. Maybe you could shed some light on this? They read as follows:

        19CG 13760/28 or
        19CG | 3760/28


        • Brian Harding
          October 27, 2022 / 4:52 pm

          Hi Ku, sorry for late reply. The ‘line or 1′ is a letter T that has not printed properly. T3760 is the model number of the speaker. 19CG is the date code, which is 19th March 1997. Ignore the ’28’ it’s just an inspection code for the Celestion staff.

          Hope that helps, Brian.

    • William Davis
      March 1, 2023 / 10:18 pm

      In the g12h, what does the h stand for?

  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
      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.


    • Brian Harding
      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,


  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
      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!


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

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

    • Brian Harding
      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,


  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
      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
      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.

      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:


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


      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
      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


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

    • Brian Harding
      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
      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,


      • John
        January 28, 2021 / 9:33 pm

        Hi Brian,

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


  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.


    • Brian Harding
      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
      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.


      • 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
          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.


  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
      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
      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.

  16. August 13, 2021 / 7:09 pm

    Thanks for all the info! I do have a question about some of the numbers on the chassis date stamp. I have a mesa 4×12 all the speakers are stamped 18AJT4335 / 03. I understand everything but what is the “03”?

    • Brian Harding
      August 14, 2021 / 10:17 am

      Hi, that is just the ‘inspection code’ and can be ignored for dating purposes.

      regards, Brian.

  17. Oliver
    December 3, 2021 / 8:32 pm


    I’ve got a Chinese made Celestion Vintage 30 with serial a serial number starting with GK. This seems to indicate it was manufactured in July of 2000. However, the serial number is located on a magnet sticker, which I understand didn’t come into effect until 2001. Also, the T number end with an “A”, which I understand didn’t start until 2003 at the earliest.

    Any help in accurately dating this would be greatly appreciated!

    • Brian Harding
      December 4, 2021 / 5:23 pm

      Hi, can you send me some photos of it please? info@bygonetones.com You are right the A and B after the T number didn’t come until around 2003 or later. Could it be an X rather than a K? for 2012?


  18. Tom Henry
    January 3, 2022 / 1:06 am


    I have a Vintage 30 with the magnet sticker which reads 09MQ. From your chart I would guess this speaker to be from 2005…correct? But, what month was represented by the letter M? I have checked to make sure I didn’t misread the code.

    Your information is extremely valuable and I appreciate all you have done.

    Thanks so much!

    • Brian Harding
      January 6, 2022 / 12:19 pm

      Hi Tom, the letter M would represent December. Hope that helps, Brian.

  19. John B
    January 10, 2022 / 7:22 am


    I have a Mesa OEM Vintage 30 (T4335) with a date code that doesn’t fit the format. It has a magnet speaker, so it’s post 2001. The date code is 08 C. The sticker isn’t damaged or anything like that. It doesn’t habe a B at the end of the type code so I would think it is pre 2008ish.
    Recently also saw a Marshall OEM V30 (T3897) in a facebook group with the date code 12 D. Any idea when these were made? Thanks

    • Brian Harding
      January 12, 2022 / 11:52 am

      Hi John, sounds odd. Can you send me some photos please? info@bygonetones.com However, if the digit for the year has not printed for some reason then you will struggle to date it accurately. Apart from the clues you already have, like the magnet sticker and the lack of the A or B at the end of the T number. Sounds like it is circa 2001 to 2004 to me. I need to do more research into when exactly they started printing the A/B after the T code, but I know it was for a manufacturing legislation that came in around 2003 / 2004. regards, Brian.

    • Paul
      October 20, 2022 / 7:49 pm

      Hi John, I also have a Mesa OEM Vintage 30 (T4335) with a date code that doesn’t fit the format. It has a sticker on the magnet speaker, so it’s post 2001. My date code is 22 B. It also doesn’t have a B at the end of the T4335 type code. From research obtained from Andrew ‘Nolly’ Getgood from , if you look at the Mesa Boogie serial number next to the speaker jack plate, on the rear of the cab, the beginning of 2002, Mesa serial numbers are approx C-43000ish. Mesa serial numbers end of 2003 is C2-47xxx’ish. As my serial number is C-44751 on my Mesa Tradional 412 cab, I’m guessing my speaker date is most likely 2002/2003 I’m not certain if 22B is 22nd Feb in those years though? Andrew also mentioned the Mesa V30 speaker type numbers changed to T4335B around 2005/2006. Hope that helps!

      • Brian Harding
        October 27, 2022 / 5:19 pm

        Hi Paul, sorry for late response, and thanks for the info. Fwiw, the letter A or B at the end of the T number does not indicate a different specification for the speaker. So a T4335B is (in theory) made to the same specification as a T4335A. If you can hear a difference in tone between those model codes, it is probably due to different parts suppliers used through the years, and /or the ageing process in general. Hope that helps, Brian.

  20. Lee walker
    March 17, 2022 / 1:20 pm

    Hi John
    My Celestion g12l only has 4ohm, 2712, 21ME430610 and Celestion printed on it the big number goes up the leg and the 2712 is on the cone, any help with info on date wattage etc would be great
    Thanks Lee

    • Brian Harding
      March 17, 2022 / 7:22 pm

      Hi Lee, can you send me some photos please? info@bygonetones.com

      ’21ME’ is the date code, 4306 is the model number (T4306), and 10 is the inspection number. 21ME should translate as 21st Dec 1995. However I think it is unusual for the T to be missing from the model number. I would like to see photos of it to be sure.

      I am not familiar with the T4306 model speaker, so don’t know about power handling etc, but if you email drdecibel@celestion.com they should be able to tell you more about it. They have every speaker model on file there.

      regards, Brian.

  21. Emanuel Boggia
    March 1, 2023 / 6:06 pm

    Hello Brian,

    I have some speakers that don’t fit the format.
    They are Celestion Vintage 30 T4416B (Mesa OEM 16 ohm).

    They have the white paper sticker (post-2001) and the B suffix (post-2005) but their code is 04CA (4th of March 1991). Any clue how to read this?

    Here there is a quick picture:
    Thanks for sharing all this research with us!!!

    • Brian Harding
      March 1, 2023 / 6:49 pm

      Hi Emanuel, 04CA is likely 4th March 2015. Don’t worry too much about the stamp format of MYDD or whatever, they didn’t always stick to them.

      Hope that helps,


  22. Steve Counsel
    April 14, 2023 / 5:35 pm

    I’ve got a 10” alnico speaker 31AM stamped on the front gasket, on the badge on the magnet it looks like it says ZIORO 1595 the “I” could be a 1 but it’s not clear, anyone have any idea what this is? I’m thinking maybe an organ speaker of some kind? I’m thinking about putting it into a practise amp but can’t get a stable ohm reading with a multimeter?

    • Brian Harding
      June 11, 2023 / 10:12 pm

      Hi Steve, sorry for the late reply, I’m not familiar with that speaker model sorry, but 31AM would be the date code – likely 31st Jan 1967. The ‘1595’ is likely to be the model number of the speaker. Not sure about the ‘ZIORO’. If you email drdecibel@Celestion.com quoting the 1595 model number, they should be able to tell you more about it. regards, Brian.

  23. SgtThump
    June 2, 2023 / 5:58 pm

    I’m stuck. I have Greenbacks in an old Marshall cab. The serial of the cab made me think it was made in 1993. But it looks like the codes stamped on the Celestion speaker frames are 2001?

    23L QT1224 / ?
    23L 0T1224 / ?

    I think the 4th character is a Q, but it could be zero or O. At the end, there is a slash and something after it I can’t make out.

    Can you help? Thanks!

    • Brian Harding
      June 11, 2023 / 10:00 pm

      Hi, sorry for the slow reply. Can you send me some photos of these please? info@bygonetones.com If correct, the date code ’23LQ’ would be 23rd Nov 2005. The speaker model number is likely to be T1221 rather than T1224. The digit after the slash is likely to be the inspection number and can be ignored. It is possible the speakers are not original to the cab. Some UK made greenbacks from that period did have the date codes on the chassis leg. regards, Brian.

  24. Tristan
    July 20, 2023 / 12:46 am

    Thank you for the info! Maybe you can help with a code from my Classic 30s :


    The “B” looks to be in a different font than the remaining characters. Any help would be most appreciated!

    • Brian Harding
      July 23, 2023 / 12:38 pm

      Hi Tristan, it is probably a number 8 rather than a letter B. So ‘8HH’, and that would likely be 8th August 1998.


  25. MarkQAZ
    September 30, 2023 / 3:28 pm

    Hi Tristan,

    I bought a recent vintage 30 that doesn’t seem to align with the chart above. It looks like this Celestion has a barcode and it is labeled as GL157946N50. My guess is it is Jul 2023?

    • Brian Harding
      September 30, 2023 / 6:35 pm

      Hi Mark, sounds odd, can you email me some photos please. info@bygonetones.com

      thanks, Brian.

  26. Meindert van der Werff
    November 5, 2023 / 2:07 pm

    The code on my Celestion G12M is : 11 el T1220/16 . Could you tell me the date of production is ? Greetings from the Netherlands !

    • Brian Harding
      December 6, 2023 / 3:21 pm

      Hi, sorry for the late reply, only just noticed your message. 11EL in that style would be 11th May 2001.

      regards, Brian.

  27. George
    November 18, 2023 / 4:38 pm

    Hello, I might have a weird case, or maybe not 🙂
    Inside a 4×12 Marshall angled cabinet, model 1935, serial 44190 there are four T1221 identical Celestion speakers, “pre-rola” label with date stamp FC51R – Ignoring the last R, I assume the FC51 is the date code. But 51 has no meaning, might be a typo? So is it 15th June 1970?

    • Brian Harding
      December 6, 2023 / 3:24 pm

      Hi, sounds like a typo or smudged print. Probably ‘FC21’ – 21st June 1970, sounds about right for the cab serial, but email me some pics if you can to confirm: info@bygonetones.com

      regards, Brian.

  28. Eero
    December 12, 2023 / 11:18 am

    Hello! I happened to find a G15C from inside an old (made late 70s-early 80s) DIY 2×15″ I’ve had for almost 15 years. The speaker is missing the green plastic cap, so I only found out what it is recently, after taking it out and spotting Celestion codes on the rim! Model T1102, 47 751 002 on the cone. The other one’s a vintage Goodmans, so I guess I could be considered lucky 😀 (paid pennies for the cab back in the day)

    Anyway, the date code seems odd considering the information on this page. It says 08CD. It’s DDMY so that would point to 1959 – which is absolutely impossible. It’s probably not a fake speaker because I know the cab’s history far back enough. 1971 is likely though, so did they use a different date code on larger speakers or could this be a stamping error?



    • Brian Harding
      December 13, 2023 / 6:00 pm

      Hi, yeah Celestion didn’t always stick to the stamp format. ‘CD’ is likely March 71, combined with that style of pulsonic cone stamp. Try not to focus on the stamp format too much. It can be confusing. Whilst the stamp format information is correct generally speaking, unfortunately Celestion didn’t always stick to it, so it is not an exact science.

      Hope that helps, Brian.

  29. Steph
    February 9, 2024 / 3:04 am

    Hi, is this where I am able to ask a question about whether markings on a 60’s G12M are legitimate? Please let me know.



    • Brian Harding
      March 17, 2024 / 6:52 pm

      Hi, yes ask away.


  30. R G
    March 16, 2024 / 9:38 pm

    I have a couple of alnicos, a cream and blue both of which just have dd then one letter so the cream is clearly printed 10A then follow but the t number. Why is it missing a letter? Is it just the first lot of production?

    • Brian Harding
      March 17, 2024 / 6:51 pm

      Hi Roman, can you email me some pics? info@bygonetones.com thanks, Brian.

  31. April 5, 2024 / 7:03 pm

    I have had a big, old 9″/23cm-diameter Celestion speaker since childhood in the late 1960s and it seemed like a museum piece even back then. My assumption about its origins are that it was a public address speaker at the school where my late father taught as that’s where mystery items in our household usually originated. The date stamp appears to be on the rim, backing up that apparent great age. Unfortunately, the rim is rusted around where the date stamp apparently is so it’s very difficult to tell what it says. It looks sort of like ’05AG’ to me, the only thing about which I am absolutely certain being the ‘A’. The figures and letters of the model no. are also fairly difficult to make out and there is a place where one is unsure whether it’s a figure/letter or whether it’s a blank space. Here are those I think I can read – Z16M6 (space?) 1726. The magnet is surrounded by a thick, heavy back-brace (if that’s the technical term!) with “Celestion – The very soul of music” on the badge. If you can come up with an at least approximate date, Brian, that would be very welcome and if you cannot well, so be it!

    • Brian Harding
      April 23, 2024 / 12:41 pm

      Hi, sounds like one of the early radio extension speakers made by Celestion. Not really my area of expertise, but the 05AG is probably the date code representing 5th Jan 1950. I would guess 1940’s / 1950’s sounds about right for it. The Z16M6 and 1726 likely being the model number of the speaker. A vintage radio forum or facebook group might be able to give you a better response. Hope that helps, Brian.

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