Celestion occasionally printed their date codes with the month and year back to front by mistake. Eg ‘HA2’ instead of ‘AH2’ for 2nd Jan 1975. A simple typo but it can be very misleading.
Year by year Celestion made small visible changes to their speakers, so an easy way to verify the date code is just to identify these features. The most obvious ones being:
- The colour of the magnet cover
- The cone stamp
- The location and general appearance of the date stamp
- The label
If you can familiarise yourself with the transition periods for these details you will find it a lot easier to date your speakers accurately. My blog post ‘How To Date Vintage Celestion Greenbacks – without using a date chart’ has all the information you need, and I’ll be referring to it throughout this post.
Celestion were mainly only using the cream coloured magnet covers from spring 1974 to mid 1975. So this is a really easy way to date your speakers.
The date code ‘GM4’ on this speaker might appear to be July 1967 or July 1979. However, the general appearance of the speaker tells us it is a mid 1970’s speaker, and therefore we know the date code is back to front and should be ‘MG4’ – 4th Dec 1974.
Some of the visible features that indicate this are:
- The cream magnet cover – found spring 1974 to mid 1975
- The 0444 cone stamp – found late 1974 to mid 1975
- The inspection letter (‘X’ on this speaker) – found 1969 to 1976
…and there are a few more smaller details that I won’t bore you with.
We can also consider the features of the other contenders:
A speaker from July 1967 would be a 20w pre-rola greenback with the date code printed on the front gasket.
A speaker from July 1979 would be a ‘blackback’ with no inspection character in the date code and a 444 stamped Kurt Mueller cone.
All very different looking speakers.
Thankfully, most pre-rola speakers do not have back to front date codes, however watch out for them around late 69, this seems to be a bit of a hotspot for them.
The date code ‘BK’ here represents Oct 1969. Not Feb 1965 or Feb 1977.
We know the speaker is from 1969 just by the general appearance of it. Here are a few of the main indicators:
- Green magnet cover – typical from 1966 to 1973
- The 25w 16 Ohm G12M pre-rola label – typical from late 1968 to spring 1971
- The 102 003 pulsonic cone stamp – typical from 1968 to spring 1971
- The added inspection letter – typical from 1969 to 1976
Feb 1965 is before the T1221 was even being made to my knowledge.
Feb 1977 would be a very different looking speaker – a ‘blackback’ with a Rola Ipswich label, and a ‘1777’ stamped Kurt Mueller cone.
1972 vs 1973 Greenbacks
Another common date code to find is the ‘EF’ stamp. It appears to be May 1973 but is actually June 1972 and should be printed ‘FE’.
Here are a few of the main indicators that point to 1972:
- The smooth paint finish (known as ‘golden sand’) indicates it was likely made before Oct 1972.
- The ‘102 3’ cone stamp is typical from April 1971 to around Feb 1973
- The day of the month omitted from the date code is typical from Dec 71 through to Sept 72
For direct comparison here is a typical greenback speaker from mid 1973. Spot the difference:
- ‘Hammered’ paint finish to the chassis – typical from Oct 1972 onwards
- ‘3’ cone stamp – typical from Feb 1973 to Aug 1973
- Day of the month included in the date stamp
Celestion but stamp on back ok magnet EW 13 3972 0 has metal center cone
Hi David, that is 13th May 1988, speaker model T3972.
“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.” That is taken from my date codes page here: https://www.bygonetones.com/celestion-date-codes.html
Thank you for the date.now I understand the code more on that year stamp, by looking at your code page .first one of this stamp i have seen on magnet back. What are these used for, guitar or pa ?
Hi David, I am not familiar with that speaker model T3972. Can you send me some photos of it? firstname.lastname@example.org If it has the ribbed cone without a whizzer they should usually sound good with guitar. Also if you email email@example.com they have every speaker model on file there and should be able to tell you more about it.
Hi, I bought a white tolex 4×12 over 25 years ago that still has 4 25 watt cream back speakers in it. The date codes for 3 of them are December 1973, and one January 1974. Does that fall into the creamback period? The speakers haven’t been changed as far as i know…
Hi, I would expect to see grey magnet covers on those rather than cream. Personally I have not seen the cream covers that early before, but I guess it is possible. Can you send me some photos please? firstname.lastname@example.org
Thanks Brian! Photos sent.