The Date of your Wurlitzer Electric Piano

  • You can date-confirm your own Wurli!  Please do and send me the data. I had a Eureka moment recently, and figured out that, by August 1962 at the latest, all Wurlies had a consistent, cryptic date-stamping system for both the keys, the keybeds (or balance rails) and, later on, the backs of the main rails (where the damper arms and hammers are mounted).  The keybeds will often have a 5-digit code consisting of YMMDD (colors my own.) The keys and main action rails will be stamped YMMDDXXX; sometimes a digit at either end will be smudged or faint.  It is not yet clear what those last “X” digits represent (perhaps an inspector/employee code).  The year-digit (Y) doesn’t include the decade; so, a May 23 1974 keybed will be stamped “40523,” with the “4” meaning “1974.”  (I am pretty sure, BTW, that I am the first person to have cracked this date-stamp code among the people currently fixing these things.  If I may toot my own horn.)
  • The very earliest 140’s (and presumably the 145’s and 720’s) used different stamp codes which have not yet been decoded.  Perhaps YWWxxx. (Year, and week of the year.)  Main rails may also have strange, misleading stamps. 2-digit stamps on keybeds may indicate week of the year, as well. (So far, data seems to be consistent with other clues.)
  • This site can help decode dates found on transformers and volume pots.  These will generally predate the stamps found on the wood, but typically only by a few months:  http://www.triodeel.com/eiacode.htm
  • This site counts weeks of years.  Here’s the link for 1962: http://www.epochconverter.com/weeks/1962
  • Since no model of Wurlitzer was produced for more than 10 years, you can use this chart to get a general sense of the period of your model, then use the stamp on your keys and keybed to pinpoint it.  The key stamp date is NOT the assembly date, but probably the date the keys were cut. (Theorized because: Sometimes a single keybed is made from two pieces of wood, each with a different stamp at the transition point).  Still, usually, it is close.  (Sometimes the upper and lower ends of a keyboard have different date stamps, if two pieces of wood were used.) Triangulating using as many date stamps as possible (from keybed/balance rail, keys, transformer, speakers, volume knobs, and amp) will give you a pretty close idea, and usually (not always) the stamps on the wood will be among the latest dates. In one known case, the keys are from 1971 but the keybed is stamped 1973; in another, a very early 200 has a later transformer stamp than the keystamp date, by months; but usually the keys are stamped within a week earlier or later than the keybed.  (If you do send me data, PLEASE include the serial number and model number, including any letters like “A” or “B” or “P,” from the instrument’s badge, and the precise literal stamp numbering, and their locations.  The letters are crucial: a 140B is a different animal than a 140. Photos, pref multiple, are much better, too.)
  • Eventually, as more data rolls in, this page may include ways to approximate the year of your Wurlitzer by serial number.