AKG D12 - Replacement capsule

Transmutant

New member
Hi, I will be constructing one for myself and can replicate the process for others if anyone is in need.

My model will not have the humbucking coil, at least not at first, but will utilize the original bass chamber and the original mounting jig. I will be heavily modifying a large dynamic capsule to achieve 20Hz-18KHz response, hefty bass & slight peak around 4-5k region. Will work as a vocal/all-around mic also.

My original D12 capsule is beyond repair but I can do comparison recordings with other mics: AKG D3600, Shure Beta52, Superlux Pro218A, Shure SM7, AKG D330.

This thread is to see if there is market for this part. At this monent I don't have actual number for price.

*T*
 
Hi there,
There are plenty of shot D12s sitting in drawers all around the world.
I'm not sure how sought after an alternative/replacement would be, but true-to-original diaphrams+coils would fly off the shelves. ;)

I have a mint one here, and two dead ones. Coil wires gone. :(
 
Thanks for the comment. My coil was broken next to the winding, no way to repair.

Making true to original capsules + windings would be something else. Unfortunately creating something like that witout the original gear would be next to impossible. I took the original capsule apart to the last part... And boy there was a lot of those.

I will be taking apart 36mm diaphram capsule (shure sm57 is less than 30mm) and putting it together without most parts, the manufacturer has made good capsule but soffocated the coil with too little air/bass ventilation. I will also be turning in lathe a new alumium tube-body behind it to keep it cardioid, the original bass chamber connects behind it with the seal rubber ring and 4 screws.

Sure, it's not like the original but it's something other than installing a generic shure/akg capsule in it.
 
It's such a shame there's no longer a source for replacement capsules, or even just diaphragms and coils.
I wouldn't call it a user friendly job but any decent tech would/should be able to fit the latter.

I looked for a while in the hope of finding another microphone which shares the same diaphragm. I think I did but, unfortunately, it was glued rather than clamped, in that model.

Regardless, it sounds like an interesting project.
Hope it goes well and you update us on the progress. :)
 
Thanks for the comment. My coil was broken next to the winding, no way to repair.

Are you sure about that? I've repaired quite a few D12's with broken coil wires. Extremely finicky, of course.

Making true to original capsules + windings would be something else. Unfortunately creating something like that witout the original gear would be next to impossible. I took the original capsule apart to the last part... And boy there was a lot of those.

It's a complicated capsule for a reason. The D12 wasn't intended as a bass-drum mic. It was designed as a vocal mic...

I will be taking apart 36mm diaphram capsule (shure sm57 is less than 30mm) and putting it together without most parts, the manufacturer has made good capsule but soffocated the coil with too little air/bass ventilation. I will also be turning in lathe a new alumium tube-body behind it to keep it cardioid, the original bass chamber connects behind it with the seal rubber ring and 4 screws.

That limited ventilation was by design too. It's also the reason why there is an expansion chamber.

Sure, it's not like the original but it's something other than installing a generic shure/akg capsule in it.

Why don't you make a completely different mic? Should be a lot easier. Modifying a D12 is next to impossible imho. It's probably the most complicated dynamic single capsule design ever.

I've repaired quite a few of these. They are strange beasts. One of them, belonging to a famous drummer, wouldn't stay alive in his favourite kick drum. Just one or two kicks of the pedal and it almost died. Output level dropped 40 dB. It came back a few days later every time. And it worked consistently in any other kick drum. Never got to the bottom of that problem. In those days, I still had access to new capsules, so it was swapped out.

These days, it's not worth looking at most of the D12's on the market. Most being sold have serious flaws. The latest one that came in, had no expansion chamber, no transformer and a capsule from a tourbus speech mic in it. Just an expensive fake. Fortunately, the guy who bought it, also had a D12 that had an ugly, broken case. So I swapped the internals. Now he has one D12 that looks good and sounds good and some leftovers...
 
Are you sure about that? I've repaired quite a few D12's with broken coil wires. Extremely finicky, of course.

I'm pretty sure, tried to pull out some more, slowly, but keeps breaking all the time. Can't see where it last broke cos so close to the glued windings. I'll call it a lost case.

It's a complicated capsule for a reason. The D12 wasn't intended as a bass-drum mic. It was designed as a vocal mic...

Looking at the original specs I believe it to be so also.

That limited ventilation was by design too. It's also the reason why there is an expansion chamber.

Maybe there was a misunderstanding here. I mean the capsule I'm modifying to go into the d12 body had poor ventilation, the 36mm one.

The D12 is pretty complicated indeed. It's actually not "large" at all. I'd say the membrane is less than 28mm that moves. The magnet housing and felt dampening gives it much bigger appearance.

I might make a completely "new" microphone from this modified cardridge. I was thinking that the D12 body is so cool that others would also like to get it back into action with fitting a part that can be used, both with vocals & kick drum etc.
 
I'm pretty sure, tried to pull out some more, slowly, but keeps breaking all the time. Can't see where it last broke cos so close to the glued windings. I'll call it a lost case.

Sometimes it can be done, sometimes, it can't. It's a finicky job anyways...

Maybe there was a misunderstanding here. I mean the capsule I'm modifying to go into the d12 body had poor ventilation, the 36mm one.

Of course I misinterpreted that...

The D12 is pretty complicated indeed. It's actually not "large" at all. I'd say the membrane is less than 28mm that moves. The magnet housing and felt dampening gives it much bigger appearance.

I might make a completely "new" microphone from this modified cardridge. I was thinking that the D12 body is so cool that others would also like to get it back into action with fitting a part that can be used, both with vocals & kick drum etc.

I've sent you some info in pm, in case you really want to restore it to "genuine" D12 status. If not, I'm looking forward to your build :D
 
I would be very interested in a replacement capsule or any help to try and fix the one i have. mine has the lead wires from the brass ring but they are broken off right in the paper gasket.
 
Back
Top