It is possible to date a vintage greenback with some accuracy, without looking at the date code at all.
Year by year Celestion made small visible changes to their speakers. The most obvious ones are:
- Colour of the magnet cover
- Cone stamp
- Location and general appearance of the date stamp
If you can familiarise yourself with the transition periods for these details you will find it a lot easier and quicker to date your speakers more accurately.
The earliest 12″ ceramic speaker I have ever seen was a PA model made in late 1964. The earliest G12M guitar speaker I have ever seen was a T1221 made in March 1965.
The last 25w G12M and 25w G12H models seem to have been phased out in 1979, in favour of the higher power handling speakers such as the G12-65 and G12-80.
So if you are trying to date a vintage greenback (G12M or G12H) we can immediately narrow the possibilities down to roughly 1965 to 1979 because this is the only time they were being made. No more of this 1956 nonsense please!
The first reissue greenbacks came out in the late 1980’s – I will not be mentioning those here.
The information given below is mostly based on the T1221 model. This is because the T1221 seemed to be first in line whenever any changes were introduced. Probably due to higher production numbers compared with other speaker models.
So please keep this in mind – in most cases the dates shown are for rough guidance only, rather than exact cut off dates. Transitional overlaps should be expected, and different speakers models, especially 8 Ohm models, may have slightly different transition periods.
The colour of the magnet cover gives us an approximate date range for when the speaker was made.
- Rola Thames Ditton label only = mid 64 to early 66
- Green = Jan 66 to Aug 73
- Grey = Aug 73 to Apr 74
- Cream = Apr 74 to Apr 75
- Black = Apr 75 to 79
Note – If you are struggling to date a mid 70’s creamback speaker, it is very likely the date code is printed in reverse. This was very common during the creamback period, and trips up a lot of people.
Date Code Location & Appearance
Through the years Celestion moved the location of the date stamp and altered its appearance:
- On the front gasket = 52 to Mar 68
- Horizontally on the frame leg = Apr 68 to Dec 68
- Vertically on the frame leg = Jan 69 onwards
- Additional inspection letter included = Jan 69 to Sep 73, & Sep 74 to Sep 76.
- Day of the month missing = Dec 71 to Sep 72
- Rola Thames Ditton labels = mid 64 to early 66
- “Pre-rola” 15 Ohm labels = Jan 66 to Apr 68
- “Pre-rola” 15 Ohm labels with “5w more” sticker = Apr 68 to Aug 68
- “Pre-rola” 16 Ohm labels = Aug 68 to Apr 71
- “Transitional” Rola Ipswich labels (no speaker symbol) = Apr 71 to Dec 71
- Rola Ipswich labels = Dec 71 to 80
- The ‘1 tab’ chassis – used upto mid 1969. The solder terminal does not usually have cutouts at the sides
- The ‘4 tab’ chassis – used mid 1969 onwards. Solder terminal usually has side cutouts.
- Smooth paint = standard on most greenback models from 1964 to Sep 72
- Hammered paint = standard on most greenback models from Oct 72 onwards, but can be found on some earlier models such as T1134.
|75Hz stamps||55Hz stamps|
|'H1777' or '**/H1777'||mid 1962 to 1966||'SP444' or '**/SP444'||1966 to 1967|
|'003' or '**/003'||mid 1966||'014' or '**/014'||mid 1966|
|'**/102/003'||mid 1962 to 1967||'**/102/014'||1966 to 1967|
|'** 102 003'||mid 1962 to Apr 1971||'** 102 014'||1966 to mid 1971|
|'102/3' or '102 3'||Apr 1971 to Apr 1973||'102/14' or '102 14'||Apr 1971 to mid 1973|
|3||Apr 1973 to Apr 1974||14||1972 to Apr 1973|
|1777||Apr 1973 onwards||'102/30' or '102 30'||Apr 1971 to mid 1973|
|RIC***||Aug 1973 to Apr 1975||4||Apr 1973 to Apr 1974|
|98700||May 1974 to Jun 1974||5||Apr 1973 to Apr 1974|
|0444||Aug 1974 to Apr 1975|
|444||Late 1975 onwards|
|RIC***||Aug 1973 to Apr 1975|
|'**' = a variable two digit number said to represent the week of the year the cone was made||1105 or 5011||1976 to 1980|
|'***' = a variable three digit code with unknown meaning|