What to watch out when opening a Beyer M88

At your risk.


Only do this if the mic is already in a terrible condition unless you know.


To be honest I do not know.


This is just some of my experience. The non working for parts mic that arrived looked as if it was used as a drum itself rather than a drum mic.


It is likely that while opening it up things may become even worse.


The XLR connector can be uncrewed after removing a very tiny screw near the end of the Beyer logo sticker. The tiny screw needs the exact size tiny screwdriver of great quality, otherwise the screw can be damaged. Watchmaker quality screwdrivers should be used. The wires inside the XLR compartment are very short and will be twisted many many times. It has to be done very carefully. But now thinking about it it is unlikely that the problem is there.


The mic capsule protective shell can be removed by removing 3 small screws. I washed mine with detergent and tooth brush as it was in a terrible state. Then used methylated spirit. It still needs more cleaning as the light does not pass through clearly from all points of the double mesh. The mic should be under a magnifying glass. Handling should be extremely delicate. Take your time. Breaking a tiny wire can cost much more time. Watch carefuly before trying to touch the capsule or turn it in order to start pulling it out. Handling may cause wires to break. It is important to find out where to place your fingers. More important where to not place your fingers. Or the so delicate wired may had already been broken.


There is a hum canceling coil wound around the capsule. This should be connected in series with the voice coil. If this is broken the mic won't work.


I do know yet how to proceed. Found 2 soldering terminal instead of 3. Beyer has been contacted for capsule replacement parts and service manual.


Fortunately a boxed Beyer M61 came by post today. It looks like a baby M88 and stronger and it sounds great and so big. Like a giant. (See next post).


For what was found inside (long acoustic tubes etc) see tomorrow's post:
https://euroelectron.blogspot.com/2019/01/similarity-between-akg-d12-d20-d25-and.html