Anyone know what this microphone is?

[mikaelea]

I'm trying to fix this microphone which has lost almost all output. I have checked for shorts and loose solder joints but found nothing wrong. Does anyone know what kind of microphone it is? Type, brand, model? Anything that could lead me to solving the problem would be much appreciated! :-)

https://drive.google.com/file/d/19OX...ew?usp=sharing
https://drive.google.com/file/d/1Ib-...ew?usp=sharing
https://drive.google.com/file/d/17Cg...ew?usp=sharing
https://drive.google.com/file/d/1W8R...ew?usp=sharing

[nevetslab]

Made in Austria suggests very early AKG or Norelco Condenser mics. I'm trying to recall the website that is a defacto museum collection of vintage microphones to give a clue to it. I haven't yet started that search, but will see what I can find. The shape of the deep grille assemblies on the shank of the mic looks familiar. Is this an XLR Male connection? Have you found any date codes inside?

[nevetslab]

Radiomuseum at http://www.radiomseum.org/museum/usa...ilwaukee/.html was one of them. Last time I had visited the site, I didn't have any issue getting in, but now, there's a membership fee. There is a Forum on this site, but still no photos, but potential clues. Philips was another brand of mics out of Austria to consider, as well as Siemens.

Another site I found at http://museumofmagneticsoundrecordin...crophones.html has a good photographic record of some collections, though I didn't find this mic in there.

Also, check www.coutant.org. That was the site I was remembering, which has excellent photos, schematics inside details & graphs from the original documents, when available.

That mic you have has the general appearance of the AKG D12E, though that mic is a cardioid dynamic in that basic housing you have on your bench. I found that listed in the collection at www.coutant.org.

[AttachMan]

Local copies:

[nevetslab]

Looking again at these photos, what I thought was an odd-looking condenser mic array inside, but now, it looks like a dynamic microphone array.....like two mic elements in series? This mic MAY BE an AKG D12E after all. Can you get any DCR readings on the wires attached to the capsule inside? I've never been inside the D12E, so I'm no certain what that element is directly below the capsule assembly. A large film capacitor, perhaps? The D12E is transformer coupled, and has taps to select the output impedance, as in the last image, it shows selectable impedances between 50 and 250 ohms. http://www.coutant.org/akgd12e/index.html

[mozz]

I have a old stereo Norelco mic from a old reel to reel, i had it apart a few years back and it does remind me of the inside.

[nevetslab]

I have a old stereo Norelco mic from a old reel to reel, i had it apart a few years back and it does remind me of the inside.

What's the connector format? Was that stereo mic unbalanced output or xfmr coupled. I hadn't thought about it being a stereo mic.

[mozz]

I think it had a 4 or 5 pin din. Don't remember if it was direct wired but I think it was.

[Wal_zz]

Definitely looks like a D12. A classic mic used for kick drum pickup.
These repair notes written by a Portugese audio engineer provide further insight into the D12. Hope they help!
https://lfpneto.me/2013/07/08/akg-d12e-repair/

[nevetslab]

Definitely looks like a D12. A classic mic used for kick drum pickup.
These repair notes written by a Portugese audio engineer provide further insight into the D12. Hope they help!
https://lfpneto.me/2013/07/08/akg-d12e-repair/

NICE FIND in the document search! Most unique in being able to 'tune' the diaphragm....not unlike thumping a voice coil diaphragm of a JBL compression driver.

[mikaelea]

Looking again at these photos, what I thought was an odd-looking condenser mic array inside, but now, it looks like a dynamic microphone array.....like two mic elements in series? This mic MAY BE an AKG D12E after all. Can you get any DCR readings on the wires attached to the capsule inside? I've never been inside the D12E, so I'm no certain what that element is directly below the capsule assembly. A large film capacitor, perhaps? The D12E is transformer coupled, and has taps to select the output impedance, as in the last image, it shows selectable impedances between 50 and 250 ohms. http://www.coutant.org/akgd12e/index.html

Great replys. The DC resistance over the coil is 47 ohms. No shorts to ground and the grounding itself seems to be ok. From what I have gathered so far it seems that, for the transformer coupled versions, the thing directly below the capsule has a transformer in it. . I have no idea what its purpose is for my mic.

I think I will try to gently remove the dust cover from the capsule assembly to see if there is dirt inside. If that is what causes the problem I might be able to solve it! If not I will have to find a suitable experienced repairer.

[S2udio]

Yes this is an early D12 possible an very early one which also came under the Echolett brand.
I put this repair guide together for GDIY a few years ago , the pictures got deleted over time but a fellow member found it on the wayback machine

https://web.archive.org/web/20150319...topic=33755.40

Unfortunately seems like you cannot zoom the images as the original , may still have them in my archive somewhere ?

Hope it helps

[mikaelea]

Yes this is an early D12 possible an very early one which also came under the Echolett brand.
I put this repair guide together for GDIY a few years ago , the pictures got deleted over time but a fellow member found it on the wayback machine

https://web.archive.org/web/20150319...topic=33755.40

Unfortunately seems like you cannot zoom the images as the original , may still have them in my archive somewhere ?

Hope it helps

Wow! That is amazing info. Thank you so much!

[nevetslab]

Yes this is an early D12 possible an very early one which also came under the Echolett brand.
I put this repair guide together for GDIY a few years ago , the pictures got deleted over time but a fellow member found it on the wayback machine

https://web.archive.org/web/20150319...topic=33755.40

Unfortunately seems like you cannot zoom the images as the original , may still have them in my archive somewhere ?

Hope it helps

Ah....Echolette! That was the other brand name I couldn't remember. Seemed they were marketed with Vox gear in the mid/late 60's. I remember seeing the D12 in that lineup.

[Wal_zz]

Full size images were uploaded to Image Shack in 2015 but are no longer available when I checked yesterday. A pity, as they would have been helpful.