However, by examining those components as a group one can determine that the instrument was produced no earlier than the latest date indicated by its component parts.In general, tubes appear to have had the shortest stock life and speakers the longest.There are a number of visual cues: anything with a foil CBS ID tag is post 1966, anything with a metal tag is prior to 1966.
Any other single speed model (45/47/51) is prior to late 1963.Recently, the production data was found and there is no longer any need for guessing.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.Most of the tone generator wax and Mylar capacitors do, as well as pre- and power amplifier multi-section can electrolytic capacitors.The code typically takes the form of YYWW, where YY is the last two digits of the production year and WW is the production week. All of the speakers in Hammond organs, Hammond Tone Cabinets and Leslie cabinets dating from 1946 forward that I have seen have production date codes stamped on them. The coding scheme is XXXYWW where XXX is the company EIA code (Jensen = 220, Rola = 285, Heppner = 575), Y is the last digit of the production year, and WW is the production week.
3227204 is a Tung-Sol tube manufactured during the fourth week of 1972.