Speaker code dating decline in online dating
The first three numbers represent the company that made the speaker, the fourth (and fifth if there are seven numbers) represent the year the part was made, and the last two numbers represent the week that the part was made during that year.
Make note that a source code beginning with 220 was made by Jenson, 328 by Utah, 285 Rola, 137 CTS and 134 by Centralab.
There should be a code stamped into the metal case on the transformer that looks something like this: EIA606-813. Apparently Music Man used the same source for it's power transformers as did Fender back in the 70's, because my MM also has the 606 source code.
Now, we come to the last three digits of the code with the 8 being the last digit of the year, and in the case of Music Man Amps this would have to be 1978, as the amps were only built from 1974 thru 1984.
Yes, you can use the power transformer as another option for dating your Music Man Amp if the original Eminence speaker has been replaced.
You also don't have to remove or get into the chassis to find the transformer, and as mentioned earlier with speakers, this needs to be the original transformer and not a replacement.
JBL makes a wide range of speakers and subwoofers both under the JBL name and also under the Altec Lansing and Harman Kardon names.
Jenson speakers are from the 1950s, and CTS and Centralab speakers were used from the 1960s onward.
This will be a 6 digit code which is inked stamped on the bell housing of the speaker.
You should be able to look in the back of your amp ,and with very little effort, spot this code.
If you are not comfortable in taking your chassis apart to look for dates on your Music Man Amp, there is an easier way to get a good idea of when it was built.
If the Amp still has the original Eminence speaker/speakers, then you can get a good idea of how old your amp is from the Speaker Source Code.