Dating rola speakers
The Celestion G12 Al Ni Co blue is a really sweet sounding speaker with just the right crisp and grit. The sound of the G12M "greenback" (25 watts) is unmistakable, and legendary. The Celestion Vintage 30 is responsible for many of the A word about the G12H: sparkle and clarity are brevity of words for this phenomienal speaker-- it is amazing!
Great sustain and power chords with midrange clarity are a rock and roll god's gift to the ears. Furthermore, G12H has a free air resonance at 55 Hz compared with many of the other Celestion speakers @ 75 Hz, which means it gives you extended bass response-- which means that the open E is Killer! All speakers sold new, manufactureer's warranty, factory sealed box-- "no open box, demo"-- fresh new...
This information is being compiled, organized and edited into a soon to be released book that details all sorts of production and manufacturing information, including tables showing serial numbers and their date of production.
Some of the entries on the age list show actual known production dates and can be used as markers to guage the quality of other entries around them.
Thanks to the Electronics Industry Association (EIA) code conveniently placed on them by the manufacturer, many individual components can be dated to the year and week of production.
Some of the component parts of Hammonds and Leslies have EIA codes printed on them.
What follows is a breakdown of the more common parts and a description of their codes.
In general, tubes appear to have had the shortest stock life and speakers the longest.
Even the above is fraught with some risk, as replacement parts used for repair or modification will occasionally skew the overall picture.