Dating marshall cabinet
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.
So ‘GB17’ on the photo above = 17th July 1969 (ignore the ‘Y’). More example date codes are shown further down the page. 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.
You might have read on the Celestion website to use the stamp format to date your speakers. 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.
From around Dec 1971 to Sept 1972 the day of the month is usually omitted: From around June 1976 the inspection letter is no longer included.
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: I have included the stamp formats in the year column headers on the chart if you want to use them.
The letter ‘T’ prefix is usually omitted from the speaker model.
From around April 1990, the ‘T’ prefix is usually included with the model number.