AKG D12 repair attempt...

[wmb]

Any suggestions for separating the spacers. I think I need to re-order them. After rebuilding two capsules one of them is still pretty thin sounding at least when connect it to a mic pre. I've gathered that raising the membrane will increase the fullness.  The upside is that it barely worked at all before and now it produces a pretty strong signal.

I haven't rebuilt the whole mic yet and it's still just the capsule with the bass chamber. One thing about this particular capsule is the gasket on the back for the bass chamber is pretty dry and crumbly. I'm wondering if that could effect the bass response because otherwise the signal playback seem okay when I run the sweep through it.

Another thing, do the nasties sound really obvious? My sweeps have a slight buzzy quality but it's the whole sweep. I think I have heard a little momentary rasp before but there's was nothing standing out. I'm just trying to avoid having to tear it all down again.

Thanks

(P.S. I was kind of overwhelmed when I was removing screws placed some 40-50 years ago that the last person to do this was working as carefully as I was to accomplish the same goal, make a well performing mic.)

 

[wmb]

My sine wave sweep after a tear down and cleaning. Here's a video. I have no idea if I have improved it or not.

http://lovelessmotel.com/d12/d12_sweep.3gp

 

[MagnetoSound]

Sounds like you're driving it hard! Does that distortion go away if you drop the level from the generator?

 

[wmb]

I'll have to give that a try. I started out really low and it was kind of hard to tell how much LF was coming from such a tiny resonator. One post here mentioned it singing so I pushed it up a little more till I could hear it. I've spoken into the capsule with the green and blue wires connected crudely to a mic cable and the sound wasn't bad. Putting the bass chamber on really made a huge difference. I put this mic back into the shockmount before leaving the studio last night but didn't put a new end on the cable I had recently shortened.

 

[wmb]

I am in a freakin' spot! I've rebuilt two D-12's and they are generally improved quite a bit with the exception of some fizz at the upper mids and higher frequencies (>5k when recording electric bass). I don't know how to get rid of it. The membrane looked fine on both. The spacers on my capsules were pretty much fused together and I cannot separate them or move the the membrane around at all. In fact the spacers fit very snuggly between the three screws that stick up from the main body of the capsule. I'm not sure what to do to move the membrane around to position the coil in the gap more precisely. Any ideas?

The most frustrating part is how awesome the mids are for recording bass. Nice and aggressive and no tubby quality in the bass. These mics are very old versions with a metal frame.

Thanks.

BB

 

[clintrubber]

Hello,

Just wondering, has anyone experience with the budget-line AKG D11 ?  (also called D11XLR).
So not the D112, but this beast:

Have already 12(E), 421, 441 for bass-cabs, but you all know how this goes, was nevertheless wondering if the D11 could be fun to add.

They're going cheap, seem well made and as it seems they're having a different signature
than the usual (...) 'low-mics'.

Brighter, less proximity, maybe even to the extend that it's puzzling why
AKG called this a bass-mic ;-)

http://www.akg.com/mediendatenbank2/pspic/hires/95/d114280bea5b3067.jpg


Thanks !

 

[nashkato]

hi
opened up a D12/HI yesterday .
i didn't find any information on this one.
AKG manuals mention a D12/HIT but not a word about this HI.
capsule DCresistance is 50 ohm . there appears to be a transformer inside the basschamber : output DCresistance is 1K2 ohm.

in fact i only gave it a short try inspired by this thread.
i didn't have any luck moving the diaphragm by just loosening the srews and opened it up.
what can i say : it still works 
i'll report back about further attempts, right now it goes on the shelve.

ps: how did you manage to put back on the spring-metalsheet , that keeps together the caspule and the chamber ?
      had more problems doing that than any of the re-assembling of the diaphragm, etc.

 

[poctop]

Man i have done the whole thing and i found a micro clover inside the confined space life find always its way,
Dany

 

[zebra50]

You found a plant inside your mic?? 

Normally I just find insects...

http://xaudiaelektrik.blogspot.com/2011/04/strange-things-you-find-inside.html

Maybe the insect left it there? Pictures please!

 

[poctop]

I really wish i could take a picture of some quality to show but anyway i kept the particule it looks definitelvely vegetal to me it is still a greenish color and make some little cup shape form like a clover ,    interessting your article about the wierd things in mike.

hope the mike works for another 20 years now !

Cheers Mate,
Dany,

 

[archieaa1]

Hello Everyone

I read the post and pulled out my old thin sounding D12E. Moving slowly I pulled it apart, cleaned it up, and put it back together. Drum roll please...... It worked! It sounds good. I have 2- d12s and 2 D112 mics. Tested on my voice the repaired D12E seemed to have as much or maybe a little more low end than the d112. The big difference was the mids. The d12 had them and the d112 didn't. The interesting thing is the difference between the D12s. The one I repaired is a d12e with a black plastic frame and no transformer. The other D12 is a D12ES with a grey plastic frame and a transformer. I find that the mids and up sound quite the same but the older D12ES is some what weaker in the low end. Is this normal or does the older one need some attention as well? Has anybody else been able to compare the older to the newer?

Thanks for any info.

Archie

 

[Shuggie101]

Hi everybody

Sorry to dig up such an old thread but I just wanted to say a big thanks to everybody who contributed such useful advice.

I just followed he guidelines to re-build the AKG D25 that has been sitting unused in the bottom of my mic cupboard for a decade or more.

The sound started out thin, strangely coloured and, of course, totally lacking in bass. Now it sounds huge, detailed and surprisingly bright. I'm even liking it on acoustic guitar.

Mine has a transformer mounted in the bass chamber. I think it had previously been messed around with and since I'd be unlikely to use the bass roll off switching, I bypassed the switch and transformer.

Mine is a 50 Ohm D25 so I'm running the mic through the same Sowter transformer (50:200) that I use for my Reslo ribbon.

Now if anybody out there knows where to get a replacement suspension rubber - or how to make one - I'd love to know.

Thanks again

Shuggie

 

[s2udio]

Well done on the repair

As for the ""new"" on the old D series AKG's,...Unicorns come to mind !
Use your ingenuity,....modern foams come to mind ?

 

[steenamaroo]

If no one minds I think I'll keep this thread alive.

I have two d12s here in need of diaphragms.

 

[s2udio]

Unobtanium  Unfortunately.......

Have the windings gone OC ?

Hopefully someone will one day make a few DIY  D12 replacement diaphragms ... £100 each must be worth it ?

Maybe an opening for for someone with the time and patience, passion, jigs and eyes to perfect.

But I don't hold a lot of hope now AKG have a released the new version.

What have AKG come up with ?, a chinese miracle !

Must try one against my two working originals , well after all the D12 , the definitive no contest  Kick  mic,

In my ears anyway.

 

[steenamaroo]

No, the mics are perfect except the fine wires from the coil have perished.
The tail ends that enter the capsule are intact.


I kinda thought that myself. Surely someone somewhere has the capability to manufacture these?
Since we're making it up though, why not start at £30?

Incidentally, were there variations? I'm fairly sure the coil size is different between my two broken D12s.

 

[s2udio]

No, the mics are perfect except the fine wires from the coil have perished.
The tail ends that enter the capsule are intact.

Then maybe a carefully exercised repair may be possible.

 

[steenamaroo]

Nah, I don't see it.
The wires are broken right at the coil.

Thanks though.

 

[pan60]

Nah, I don't see it.
The wires are broken right at the coil.

Thanks though.

I have bee looking for a few of these for dissection, if you are interested in parting with them p.m. me.
pan

 

[bkbirge]

Nah, I don't see it.
The wires are broken right at the coil.

Thanks though.

Post pics, you never know, someone may see a way to get 'em working again.