Diff: TheHammondLeslieAgeDeterminationList

 This is one of the most commonly asked questions, and unfortunately, due to the lack of available factory records on production dates, one of the most difficult to answer. There is some help available however: 

  

 The Hammond/Leslie age determination list was initially compiled by BevisPeters, and is currently maintained by RickPrevallet. It is basically a list of dates and serial numbers for various Hammond and Leslie models. It also provides guidelines to determine, generally, the age of a Hammond, based on certain features and characteristics that changed throughout the model history. 

  

  

 !EIA Codes 

  

 Many of the components found in Hammonds and Leslies (like speakers, tubes and capacitors, for example) have numeric codes 

 !Transformer Colors 

  

 The color of the power transformer can help date an [AO-28]. 

 They came in two colors: silver (pre-1963) and black (1963 and later.) Black transformers have a four digit date stamped into the bell housing.Silver ones do not. To get an idea of the production date for a silver AO-28 look at the can capacitor's date code (235-xxxx).