Author Topic: How to date a Musitronics Mu-Tron III  (Read 2256 times)

Offline guizmo

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How to date a Musitronics Mu-Tron III
« on: August 08, 2015, 11:05:47 PM »
Hello everybody,

Is there somebody here that could help me to date my vintage Musitronics Mu-Tron III?
It's an original Mu-tron III (not 3+) from the seventies, it has the black knobs and its serial number is 08706.

Thanks

Offline Student Rhodes

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Re: How to date a Musitronics Mu-Tron III
« Reply #1 on: August 09, 2015, 11:16:15 PM »
Can you open it up and look at the manufacturer code on the potentiometers? 
Usually there's about seven or eight digits stamped on them. 
The first three numbers correspond to the manufactures, for example 137 is CTS.  The next three or four are usually an indication of the week and the year. For example, 2674 would be the 26th week of 1974, though something like 832 could mean the 8th week of 52, or 62, depending on the era of the pot.  Since yours if from the 70s, I'd expect to see four digits after the manufacturer code.

Here are the most common pot manufacturers (the first 3 digits of the source-date code):
•106 = Allen-Bradley
•134 = CentraLab
•137 = CTS (Chicago Telephone Supply, pots and speakers)
•140 = Clarostat
•304 = Stackpole
•381 = Bourns Networks
•615 = IRC (International Resistive Company)

However the latter four digits will tell you what year they're from.

Offline guizmo

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Re: How to date a Musitronics Mu-Tron III
« Reply #2 on: August 10, 2015, 02:19:07 AM »
Cool ! Thanks, I'm gonna try to see it!