Eminence speaker codes dating
Electronic Industries Association (EIA) codes can also be very useful for giving clues as to an amp's age.These codes can be found on speakers, transformers, pots, capacitors, and multi-section electrolytic "can" caps.A Super Echo Twin with serial number 404553 was made in 1964 (4), during April (04) and may have been the 553th amp made that month (553).
Unfortunately, the serial numbers are of little help for dating one of these pre-Ampeg models and EIA date codes on components were used sporadically during the early post WW-II years.
Of course, these codes are only applicable to original components, not replacement parts.
WARNING: Ampeg amplifiers, especially the high-powered amps such as the SVT and V-series, contain lethal voltages even when unplugged and turned off.
It is important to note that parts do not always contain EIA codes, especially those parts from the late 1940s and early 1950s.
Some common manufacturer codes for parts used in Ampegs include: The Michael-Hull amplifiers can be narrowed down to a date of manufacture between 19.