How to Date a Shure Microphone – Made in USA

You know how the joke goes…first you bring her flowers, take her out to a nice dinner, and then you press your lips up to her and sing sweetly into her diaphragm.

But seriously, I keep needing this info and I’m getting tired of having to Google it so I’m going to publish it on my blog.

I’d also like to note that these instructions are probably only for older Shure mics. I looked at some of my Chinese made mics and they didn’t have the two letter code on them…and honestly if it’s a new mic, who cares.

The time line is something like this – 1984 Shure opened the Mexico plant in Juarez and started assembling mics there with USA parts. They are rare but you’ll see old mics that say assembled in Mexico. Within a couple of years all manufacturing was taken over in Mexico. These mics don’t say where they were made. In 2005 Shure opened the plant in China and started making all of their high production mics there including the SM57 and SM58. Today the more costly mics like the Beta series and SM7B are still assembled in Mexico while the rest are made in China. I would speculate that all the parts are manufactured in China.

Now lets get back to the dating a mic stuff….

Ascertaining the date of manufacture of a Shure mic is harder than it seems. We’ve used more than 20 different date code schemes in the last 85 years, and the details on most of them are long lost. From a warranty perspective, it’s really only important to know when the product was purchased — not when it was actually made — so the Service department relies more on sales receipts than date codes.

Shure opened two manufacturing plants in Mexico in the mid-80’s, but I’m not certain when SM58 production began there. As far as I know, the date code does not indicate where the mic was manufactured. We probably ran parallel manufacturing lines for the SM58 in the US and in Mexico for some time, which means there would be mics from both plants with the same date code.

UPDATE: I was able to find out that, on some Shure products including microphones, we’ve been using a two-letter date code. The first letter indicates the year, and it resets every 20 years starting with “A” in 1961, up through “U” in 1980, then re-starting with “A” again in 1981. The second letter indicates the month, starting with “A” for January, “B” for February, etc. This means that your SM58 with code “RF” was manufactured in June 1978, so it was almost certainly made in the U.S. since the Mexico plants didn’t open until a few years later.

Source: chris_at_shure – https://gearspace.com/board/low-end-theory/615918-dating-sm58-oily-insides.html

Here’s what he’s talking about – unscrew the mic handle and look for the little board with some letters on it. My old SM58’s two letter code says “BJ”.

JACKPOT!!! This is absolutely the type of mic you wanna date! Woohoo! BJ baby!!!

But seriously, according to Chris at Shure’s instructions, that means this mic was born in October of 1983…because 1962 was before the SM58 was released. Pretty cool.

Thanks for reading and good luck dating old mics. I hope ya’ll get some real good BJ’s and HJ’s and DP’s and all the best mics to date.